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Climate change could make ‘droughts’ for wind power 15% longer, study says
Extreme “wind droughts” that reduce power output from turbines for extended periods could become 15% longer by the end of the century across much of the northern hemisphere under a moderate warming scenario.
That is according to a new study in Nature Climate Change, which explores how climate change could impact the length and frequency of prolonged low-wind events around the world.
According to the study, “prominent” wind droughts have already been documented in Europe, the US, northeastern China, Japan and India.
As the planet warms, wind droughts will become longer in the northern hemisphere and mid-latitudes – especially across the US, northeastern China, Russia and much of Europe – the paper says.
The study – which focuses on onshore wind – warns that “prolonged” wind droughts could “threaten global wind power security”.
However, they add that research into the effects of climate change on wind supply can help “prepare for and mitigate the adverse impacts” of these prolonged low-wind events.
Combining wind power with other energy technologies – such as solar, hydro, nuclear power and energy storage – can help reduce the impact of wind droughts on global energy supply, the study says.
One expert not involved in the research tells Carbon Brief that the findings do not “spell doom for the wind industry”.
Instead, he says the study is a “navigation tool” which could help the energy industry to “counteract” future challenges.
Wind droughtWind power is one of the fastest-growing sources of energy in the world and currently makes up around 8% of global electricity supply. It is also playing a crucial role in the decarbonisation of many countries’ energy systems.
Wind is the result of air moving from areas of high pressure to areas of low pressure. These differences in air pressure are often due to the Earth’s surface being heated unevenly.
Human-caused climate change is warming the planet’s atmosphere and oceans. However, different regions are heating at different rates, resulting in a shift in global wind patterns. The IPCC finds that global average wind speeds (excluding Australia) slowed down slightly over 1979-2018.
There have already been dozens of recorded instances of prolonged low-wind events, known as wind droughts, which can drive down power production from wind turbines.
Dr Iain Staffell is an associate professor at the Centre for Environmental Policy at Imperial College London who was not involved in the study. He tells Carbon Brief that wind droughts often “push up power prices” as countries turn to more expensive alternative energy supplies, such as fossil fuels.
For example, Staffell tells Carbon Brief that, in the winter of 2024-25, Germany saw an “extended cold-calm spell which sent power prices to record highs”. (In German, this type of weather event is referred to as a “dunkelflaute”, often translated as “dark doldrums”.) He adds:
“It’s important to note that I’m not aware of anywhere in the world that has suffered a blackout because of a wind drought.”
Capacity factorThe productivity of wind power sites is often measured by their “capacity factor” – the amount of electricity that is actually generated over a period of time, relative to the maximum amount that could have been generated in theory.
A capacity factor of one indicates that wind turbines are generating the maximum possible amount of electricity, while zero indicates that they are not producing any power.
The authors define a wind drought as the 20th percentile in each grid cell – in other words, winds ranking in the slowest bottom fifth of winds typically recorded in the region.
They look at the frequency of prolonged wind droughts and how that might change as the world warms.
The map below shows regions’ average capacity factor at 100 metres above the ground level, derived from the ERA5 reanalysis data over 1980-2022, where darker shading indicates a higher capacity factor.
It also shows 19 wind droughts recorded since the year 2000 across Europe, the US, northeastern China, Japan and India. Wind droughts are indicated by yellow triangles for local events and hashed areas for larger-scale events.
Wind droughts, indicated by yellow triangles for local events and hashed areas for larger regions. Shading shows the region’s average capacity factor at 100 metres above the ground level, derived from the ERA5 reanalysis data over 1980-2022, where darker shading indicates a higher capacity factor. Source: Qu et al (2025).The map also shows that the darker shading for “abundant wind resources” is typically found in the mid-latitudes near “major storm tracks”, including the central US, northern Africa, northwestern Europe, northern Russia, northeastern China and Australia.
Modelling windTo assess the severity of past and future wind droughts, the authors consider both the frequency and duration of these low-wind events.
To calculate wind drought duration, the authors use reanalysis data and models from the sixth Coupled Model Intercomparison Project (CMIP6) – the international modelling effort that feeds into the influential assessment reports from the Intergovernmental Panel on Climate Change (IPCC).
The authors then look at how wind drought conditions may change in the future, by modelling wind speeds over 2015-2100 under a range of future warming scenarios.
They find that wind drought frequency and duration will both increase in the northern hemisphere and mid-latitudes by the end of the century. The authors identify “particularly notable increases” in wind drought frequency in the US, northeastern China, Russia and much of Europe.
In the northern mid-latitudes, there will be a one-to-two hour increase in average wind drought duration by the end of the century under the moderate SSP2-4.5 scenario, according to the study. This is a 5-15% increase compared to today’s levels.
The authors also assess “extreme long-duration events” by looking at the longest-lasting wind drought that could happen once every 25 years.
The study projects roughly a 10%, 15% and 20% “elongation” in these long-duration wind droughts across “much of the northern mid-latitude regions” under the low, moderate and very high warming scenarios, by the end of the century.
However, the authors find “strong asymmetric changes” in their results, projecting a decrease in wind drought frequency and intensity in the southern hemisphere.
The authors suggest that the increase in wind droughts in the northern hemisphere is partly because of Arctic amplification – the phenomenon whereby the Arctic warms more quickly than the rest of the planet.
Accelerated warming in the Arctic narrows the temperature gap between the north pole and the equator and alters atmosphere-ocean interactions, which reduces wind speeds in the northern hemisphere.
Conversely, the authors suggest that increasing wind speeds in the southern hemisphere are caused by the land warming faster than the ocean, resulting in a greater difference in temperature between the land and the sea.
Record-breaking wind droughtsFinally, the authors also investigate the risk of “record-breaking wind droughts” – extreme events that would only be expected once every 1,000 years under the current climate.
They use CMIP6 models, based on historical data over 1980-2014, to assess how long-lasting such an event would be in different regions of the world. These results are shown on the map below, where darker brown indicates longer-duration wind droughts.
One-in-1,000 year “record-breaking wind droughts”, based on observed data over 1980-2014. Source: Qu et al (2025).These 1,000-year record-breaking wind droughts typically last for 150-350 hours (6-15 days), occasionally reaching up to 400 hours in regions such as India, East Russia, east Africa and east Brazil, the paper says.
The authors go on to assess the risk of record-breaking wind droughts for existing wind turbines under different warming scenarios.
The plot below shows the fraction of the CMIP6 models used in this study that project record-breaking wind droughts for onshore wind turbines.
Blue bars show the percentage of wind turbines that face a “weak” risk of exposure, meaning that fewer than 25% of models predict that the turbine will be exposed to record-breaking wind droughts by the year 2100. Green bars indicate a “moderate” risk of 25-50% and brown bars denote “severe” risk of greater than 50%.
Each panel shows a different region of the world, with results for low (left) moderate (middle) and very high (right) warming scenarios.
Fraction of models used that predict record-breaking wind droughts for currently deployed wind turbines under different climate scenarios. Blue bars show turbines with “weak” riskgreen bars indicate a “moderate” risk and brown bars denote “severe” risk. Source: Qu et al (2025).The study finds that, globally, around 15% of wind turbines will face “severe” risk from record-breaking wind droughts by the end of the century, regardless of the future warming scenario. However, different parts of the globe are expected to face different trends.
In North America, the percentage of turbines facing a “severe” risk from such extended wind droughts in the year 2100 rises from 14% in a low warming scenario to 39% in a very high warming scenario. Europe also faces a higher risk to its wind turbines under higher emissions scenarios.
However, the trends vary across the world. In south-east Asia, for example, the percentage of wind turbines at “severe” risk of the longest wind droughts drops from 18% under a low warming scenario to 11% under a very high warming scenario.
Energy securityThe planet currently has 1,136GW of wind capacity. The authors say that, according to a report by the International Renewable Energy Agency, “wind power capacity is projected to grow substantially as the world pursues decarbonisation, aiming for 6,000GW by 2050”.
The paper sets out a number of ways that energy suppliers could reduce their exposure to record-breaking wind droughts.
The authors say that developers can avoid building new turbines in areas that are prone to frequent wind droughts. They add:
“Other effective mitigation measures include complementing wind power with other renewable energy sources, such as solar, hydro, nuclear power and energy storage.”
Staffell tells Carbon Brief the study provides helpful insights for how the world’s power supply could be made less vulnerable to prolonged low-wind events:
“I don’t see this study as spelling doom for the wind industry, instead it’s a navigation tool, telling us where to expect challenges in future so that we can counteract them.”
Staffell argues that there are “many solutions” for combatting wind droughts – including building the infrastructure to enable “more interconnection” between countries’ power grids.
For example, he says the UK could benefit from connecting its grid to Spain’s, noting that “wind droughts in the UK tend to coincide with [periods of] higher wind production in Spain”.
He adds:
“Increasing flexibility and diversity in power systems is a way to insure ourselves against extreme weather and cheaper than panic-buying gas whenever the wind drops.”
Similarly, Dr Enrico Antonini, a senior energy system modeller at Open Energy Transition, who was not involved in the study, tells Carbon Brief that wind droughts “do not necessarily threaten the viability of wind power”. He continues:
“Areas more exposed to these events can enhance their resilience by diversifying energy sources, strengthening grid connections over large distances and investing in energy storage solutions.”
In a news and views piece about the new study, Dr Sue Ellen Haupt, director of the weather systems assessment programme at the University of Colorado, praises the “robust” analysis.
She says the work “would ideally be accomplished with higher-resolution simulations that better resolve terrain, land-water boundaries and smaller-scale processes”, but acknowledges that “such datasets are not yet available on the global scale”.
Meanwhile, Dr Frank Kaspar is the head of hydrometeorology at Germany’s national meteorological service. He tells Carbon Brief how additions to this study could further help energy system planning in Germany.
Kaspar tells Carbon Brief it would be helpful to know how climate change will affect seasonal trends in wind drought, noting that in Germany, wind power “dominat[es] in winter” while solar plays a larger role in the energy mix in summer. [The UK sees a similar pattern.]
He adds that the study does not address offshore wind – a component of Germany’s energy mix that is “important” for the country.
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State of the climate: 2025 on track to be second or third warmest year on record
As it passes its midway point, 2025 is on track to be the second or third warmest year on record, Carbon Brief analysis shows.
However, it is very unlikely to beat 2024 as the hottest year.
This is not surprising, as 2024’s record temperatures were boosted by a strong El Niño event that has now faded.
The analysis also finds there is a less than 10% chance that average temperatures in 2025 will be more than 1.5C above pre-industrial levels.
However, with long-term warming trending strongly upward and, potentially, accelerating, the world is expected to firmly pass the Paris Agreement 1.5C target – which refers to long-term warming, rather than annual temperatures – in the next five years.
In this latest state of the climate quarterly update, Carbon Brief finds:
- So far, 2025 has seen record warm temperatures in January, the third warmest February and June and the second warmest monthly temperatures for March through May on record.
- The world, as a whole, has warmed approximately 1.1C since 1970 – and around 1.4C since the mid-1800s.
- Neutral El Niño Southern Oscillation (ENSO) conditions are expected to persist for the remainder of the year and into 2026.
- Arctic sea ice extent hit record low levels for much of June and into early July – and remains well below the historical range (1979-2010).
In this assessment, Carbon Brief analyses records from five different research groups that report global surface temperature records: NASA, NOAA, Met Office Hadley Centre/UEA, Berkeley Earth and Copernicus/ECMWF.
These records are combined into an aggregate that reflects a single best-estimate, following the approach used by the World Meteorological Organization (WMO).
The first six months of 2025 have been very warm, each of them coming in the top-three warmest on record across all the different scientific groups that report on global surface temperatures. This is despite the presence of moderate La Niña conditions in the tropical Pacific at the start of the year, which typically suppress global temperatures.
The table below shows the rank of each month in 2025 relative to all the months since the dataset began (1850 for NOAA, Hadley/UEA and Berkeley Earth, 1880 for NASA, and 1940 for Copernicus/ECMWF). Hadley/UEA has been unusually slow in reporting data in 2025 and currently only has global mean surface temperature value available up to February.
It demonstrates how January 2025 was the warmest January on record in the WMO aggregate, March, April and May the second warmest and February and June the third warmest.
Monthly rankNASANOAAHadley/UEABerkeley EarthCopernicus/ECMWFWMO avg Jan1st1st1st1st1st1st Feb3rd3rd3rd3rd3rd3rd Mar2nd1st1st2nd2nd Apr2nd2nd2nd2nd2nd May2nd2nd2nd2nd2nd Jun3rd3rd3rd3rd3rdWhen combined, the first six months of the year in 2025 were the second warmest first half of the year in the historical record. Temperatures averaged at just 0.08C below the record set in 2024 after the peak of a strong El Niño event, as shown in the figure below.
Global mean surface temperature anomalies for the first half of the year from 1850 through 2025 from the WMO aggregate of temperature records. Anomalies plotted with respect to a 1850-1900 baseline. Chart by Carbon Brief.The figure below shows how global temperature so far in 2025 (black line) compares to each month in different years since 1940 (lines coloured by the decade in which they occurred) in the WMO aggregate of surface temperature dataset.
Global surface temperature is currently around 1.4C above preindustrial levels – in-line with the best estimate of the human contribution to global warming. Most of this warming – around 1.1C – has happened just since 1970.
However, global surface temperatures have been declining in May, April and June from highs at the beginning of 2025. This is driven in part by continued cooling of sea surface temperatures after an El Niño-driven peak in early 2024, as well as a contribution from short-lived weak La Niña conditions at the start of the year.
The figure below shows a range of different forecast models for ENSO conditions for the rest of this year, produced by different scientific groups. The values shown are sea surface temperature variations in the tropical Pacific – known as the El Niño 3.4 region – for overlapping three-month periods.
ENSO forecast models for overlapping three-month periods in the Niño 3.4 region (April, May, June – AMJ – and so on) for the remainder of 2025. Credit: Image provided by the International Research Institute for Climate and Society at Columbia Climate School.Neutral ENSO conditions are expected to persist through the start of 2026 in most models, with a handful of models showing a return to weak La Niña conditions (defined as El Niño 3.4 region sea surface temperatures under-0.5C) in the autumn and winter months. No models expect the development of El Niño conditions in 2025 and early 2026.
On track to be the second or third warmest yearCarbon Brief has created a projection of what the final global average temperature for 2025 will likely be by looking at the relationship between January-June temperatures and the annual average for each year since 1970. The projection also takes into account ENSO conditions in the first six months of the year and their projected development.
The analysis includes the estimated uncertainty in 2025 outcomes, given that temperature averages from only the first quarter of the year are available so far.
The chart below shows the expected range of 2025 temperatures using the WMO aggregate – including a best-estimate (red) and year-to-date value (yellow). Temperatures are shown with respect to the pre-industrial baseline period (1850-1900).
Annual global average surface temperature anomalies from the WMO aggregate plotted with respect to a 1850-1900 baseline. To-date 2025 values include January-June. The estimated 2025 annual value is based on the relationship between the January-June temperatures, ENSO conditions, and annual temperatures between 1970 and 2024. Chart by Carbon Brief.Carbon Brief’s projection suggests that 2025 is virtually certain to be one of the top-three warmest years on record, with a best-estimate suggesting that global average temperatures will be approximately equal to 2023.
Currently, there is a less than 1% chance of 2025 being the warmest year on record, a 51% chance of it being the second warmest and a 49% chance of it being the third warmest. There is a roughly 9% chance that 2025 annual temperatures will exceed 1.5C above pre-industrial levels.
(A single year exceeding 1.5C is not equivalent to a breach of the Paris Agreement goal to limit temperature increases to 1.5C, which has been widely interpreted to mean temperature averages over 20 years.)
The figure below shows Carbon Brief’s estimate of 2025 temperatures using the WMO aggregate, both at the beginning of the year and once each month’s data has come in. The estimate jumped notably after 2025 saw the warmest January on record, but has been relatively stable over the past six months.
Carbon Brief’s projection of annual 2025 global temperatures based on the WMO aggregate at the start of the year and after earth month’s global surface temperature data became available. The dashed line shows the prior record set in 2024 at 1.55C. Chart by Carbon Brief. Record or near-record warmth in many regionsWhile global average temperatures are an important indicator of changes to the broader climate system over time as a result of human activities, these impacts will differ as some regions experience more rapid warming or extreme heat events than is reflected in the global average.
The figure below shows the temperature anomalies for the first six months of the year relative to the 1951-1980 baseline period used by Berkeley Earth. Virtually the whole planet except a small area off the coast of Baja Mexico and in Antarctica saw temperatures warmer than that baseline, with much of Europe and Asia around 2C warmer than the 1951-1980 period.
Map of year-to-date (January-June) global surface temperature anomalies shown relative to the 1951-80 period following the convention used by Berkeley Earth. Credit: Berkeley Earth.A number of areas saw record warm temperatures over January through to June in the Berkeley Earth dataset, compared to all prior years since the global temperature record began in 1850.
The figure below shows areas of record warm temperatures in dark red; there were no areas with record – or even top-five – cool temperatures. (For more, read Carbon Brief’s factcheck on how climate change is not making extreme cold more common).
Map of year-to-date (January-June) regions that set new records (warmest through to fifth warmest). Note that no regions set cold records for the year-to-date in 2025. Credit: Berkeley Earth.Notable areas of record warmth include much of China, south-west Australia and the Mediterranean region. Western Europe, in general, was quite warm, though most land areas did not see a new record set. Overall, approximately 7% of the surface saw record warming in the first six months of the year.
In June, the western Mediterranean saw particularly exceptional warmth, as shown in the figure below. This marine heatwave was driven by a combination of short-term natural variability on top of the long-term warming trend in the region.
The temperature increase in the western Mediterranean region in July – relative to the long-term warming trend – represents the largest short-term increase in temperatures for the region since June 2003, which was a precursor to a devastating heatwave that is believed to have killed 70,000 people.
Map of June global surface temperature anomalies over the Mediterranean region, shown relative to the 1951-80 period following the convention used by Berkeley Earth. Credit: Berkeley Earth. Record-low Arctic sea ice extent in JuneArctic sea ice extent saw record lows for much of June 2025 and early July, moving out of record territory in mid-July, but remaining far below the historical range (1979-2010).
Antarctic sea ice extent has been at the low end of the historical range for much of the year, but has not set new records aside from a brief period in late February and early March.
The figure below shows both Arctic and Antarctic sea ice extent in 2025 (solid red and blue lines), the historical range in the record between 1979 and 2010 (shaded areas) and the record lows (dotted black line).
Arctic and Antarctic daily sea ice extent from the US National Snow and Ice Data Center (NSIDC). The bold lines show daily 2025 values, the shaded area indicates the two standard deviation range in historical values between 1979 and 2010. The dotted black lines show the record lows for each pole. Chart by Carbon Brief.Unlike global temperature records, which only report monthly averages, sea ice data is collected and updated on a daily basis, allowing sea ice extent to be viewed up to the present.
However, this dataset – which has been continuously measured by satellites and assembled by the US National Snow and Ice Data Center (NSIDC) since 1979 – may soon be less available.
The US Department of Defence is planning to cease provision of satellite sea ice extent data to the NSIDC at the end of July. While some other satellite instruments can be used to help fill in the gaps, the change will degrade the scientific ability to effectively track this key climate variable.
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The 1.5 degrees climate advocacy conundrum
Breakthrough has just released a new discussion paper, Warming has reached 1.5°C. What does that mean for climate advocacy? This blog is part 3 of the paper, on the 1.5 degrees Celsius conundrum.
by David Spratt
1.5°C has become the policy-making target
Until 2015, climate-policy making and advocacy was focused on the 2°C goal, which was seen as appropriate to “prevent dangerous anthropogenic interference with the climate system” (Article 2 of the UNFCCC). As an aside, how was 2°C ever considered a reasonable goal? Answering that question — it wasn’t science-based, but first proposed by an economist — may provide insight into why 1.5°C isn’t either.
At the Paris COP in 2015, the overarching goal adopted was to hold “the increase in the global average temperature to well below 2°C above pre-industrial levels” and pursue efforts “to limit the temperature increase to 1.5°C above pre-industrial levels”. Since the Paris Agreement, the focus of advocates has been 1.5°C.
The flawed benchmark of 1.5°C
Sir David King, the former UK Chief Scientist and advisor to three (Labour and Conservative) governments, reflected on his work with AOSIS on 1.5°C in Paris in 2015. The Independent journalist Donnachadh McCarthy reported that King “astounded me by saying he now realised this was wrong, and believes the passing of the Arctic tipping point has been reached... He said the 1.1°C rise that we already have is too dangerous — and candidly admitted he believed US climate professor James Hansen had been right after all in 1988, when he warned the US Congress that we should not pass 350 ppm CO2 (parts per million carbon dioxide). We have now breached 415 ppm and are heading fast towards 500 ppm, Sir David said” (emphasis added).
This is widely understood. The NGO 350.org was explicitly established in 2008 on the view that what was safe was < 350 ppm and < 1°C, a position based on the work of former NASA climate chief James Hansen, sometimes referred to affectionately as the “godfather” of modern climate science.
Likewise, in "A safe operating space for humanity", Rockstrom et al. (including Hansen and Will Steffen), proposed that “human changes to atmospheric CO2 concentrations should not exceed
350 ppm”.
But in current mainstream climate advocacy, < 1°C and < 350 ppm seem to have been dropped to
the wayside.
1.5°C is not a safe limit
Many lines of evidence show that systems have/will have passed their tipping points at 1.5°C, and tipping points are now in play, including at both poles. Coral reef systems have been in a death spiral for more than a decade. Permafrost, boreal forests and the Amazon are becoming net carbon emitters.
In September 2022, Stockholm University’s David Armstrong McKay and his colleagues concluded that even global warming of 1°C risks triggering some tipping points. At 1.5°C, “we're at risk of crossing irreversible thresholds on unique and threatened systems”, says Johan Rockström, director of the Potsdam Institute for Climate Impact Research.
This year, new research has reaffirmed that 1.5°C is too high to prevent tipping points: there is a “significant” risk of large Amazon forest dieback if global warming overshoots 1.5°C. And there is a new scientific warning that “1.5°C is too high for polar ice sheets” and the Paris Agreement target won’t protect them.
As well, Earth may have hit a point of irreversible moisture loss in its soil. And the natural sequestration of CO2 by the terrestrial biosphere peaked in 2008 and is in decline, accelerating climate change.
At a May 2008 climate conference at the Academy of Science conference in Canberra, the international guest speaker was Dr Neil Hamilton, then head of the WWF Arctic Programme. He told a somewhat stunned audience that the WWF was not trying to preserve the Arctic ecosystem because “it was no longer possible to do so”. That is, it had already passed its tipping point, at a time when global average warming was 0.8°C!
Likewise the world’s greatest coral researcher, Australia’s Charlie Veron, told the Royal Society in London in 2009 that a safe boundary for reef systems was 0.5°C.
The evidence grows that the 1.5°C target was never a safe target for humanity.
Figure 1: Climate models (CMIP6) and observations (ClimateBrink)We are already at 1.5°C.
In 2018, the IPCC mid-range projection for the world to warm to 1.5°C above pre-industrial levels was 2040. But a new World Meteorological Organization report this year indicates that Earth will cross this point in just two years, with a “70% chance that the 2025-2029 five-year mean will exceed 1.5°C above the 1850-1900 average”.
In fact, 2023 was 1.5°C and 2024 reached 1.6°C, and the running average for the last 24 months has been close to 1.6°C. A new paper (currently in pre-print) shows that for one temperature data set, the warming trend reached 1.5°C in 2024, and four other data sets show 2026.
For all practical purposes, the warming trend has hit 1.5°C, as James Hansen has noted: “Averaged over the El Nino/La Nina cycle, the 1.5°C limit has been reached”. This is also consistent with the CMIP6 model projections (Figure 1, produced by Zeke Hausfather).
1.5°C is not a point of system stability
Scientists say it is a big mistake to think we can “park” the Earth System at any given temperature rise – say 2°C – and expect it to stay there. The late Prof. Will Steffen and his coauthors in their widely-read 2018 “Hothouse Earth” paper warned that “even if the Paris Accord target of a 1.5°C to 2°C rise in temperature is met, we cannot exclude the risk that a cascade of feedbacks could push the Earth System irreversibly onto a ‘Hothouse Earth’ pathway”.
In other words, by 1.5°C, there may be so many carbon-cycle and other feedbacks under way and active system instabilities that the climate will not stabilize at 1.5°C, but rather it will move towards a new point of equilibrium at a significantly higher level. The implication is that our choice is either to cool back to Holocene (pre-industrial) conditions, or accept that the next point of system stability may be around 3°C.
This is a point that paleoclimatologists make repeatedly, that the climate’s history over the last 800,000 years shows temperature and CO2 oscillating between two levels, interrupted by abrupt instability, offering critical insights into today's rapidly changing climate. The climate see-sawed between glacials around 180 ppm which were 3-5°C cooler than recent centuries, and the warmer interglacials around 280 ppm (see figure 2). We are now approaching 430 ppm.
Figure 2: Earth system stabilityHansen says we have now left a state of system stability — the Holocene — and are headed into a period of rapid, unstable (non-linear) change driven by record-fast increases in CO2 and amplifying and cascading feedbacks. The current 1.5°C climate is not a point of system stability, which lies at a significantly higher warming when the current system feedbacks have played themselves out to equilibrium. The last time CO2 was around the current level — 3 to 3.3 million years ago — temperatures were around 3°C hotter than pre-industrial and sea levels 25 metres higher.
In other words, 1.5°C is not a destination, but a signpost on a dusty road to somewhere hotter. So it cannot be an advocacy endpoint either, from a “science-based” perspective.
UN report: Five charts explaining the rise of global food insecurity
Hunger has, on average, fallen worldwide after hitting 15-year highs in 2021 and 2022.
This is one of the key findings from the latest “State of Food Security and Nutrition in the World” (SOFI) report, an annual assessment produced jointly by the UN Food and Agriculture Organization (FAO), International Fund for Agricultural Development, UN Children’s Fund, World Food Programme and World Health Organization.
The SOFI report also examines the cost of a “healthy” diet around the world, the surge in food price inflation and the contribution of energy and fertiliser prices to overall food inflation.
In a statement, FAO director-general Dr Qu Dongyu said that it is “encouraging” to see the world making progress on hunger, but added: “We must recognise that progress is uneven.”
Below, Carbon Brief highlights five charts from the report which explain the state of food insecurity around the world.
- Hunger decreased in recent years in most parts of the world, following sharp increases in 2020-21
- The cost of a healthy diet increased around the world
- Food price inflation outstripped general inflation over 2019-25
- Gas price shocks contributed to high commodity prices
- Fertiliser prices have remained high following Russia’s invasion of Ukraine
Since 1975, the FAO has tracked the prevalence of undernourishment – the proportion of the population in each country who does not regularly consume sufficient amounts of food for sustaining a healthy life.
These estimates are used to assess progress on achieving global goals, such as the 2030 Sustainable Development Goals (SDGs), launched in 2015.
The left-hand chart above shows the number of people facing hunger each year from 2005-24. The right-hand chart shows the percentage of the population facing hunger over this time period for the world as a whole (red), Africa (dark blue), Asia (blue), Latin America and the Caribbean (light blue) and Oceania (cyan).
Over the past 20 years, undernourishment broadly decreased until 2016 and then began to rise sharply in 2020 and 2021. This increase coincided with the Covid-19 pandemic.
The report estimates that the population facing hunger in 2024 was between 638 million and 720 million people, or between 7.8% and 8.8% of the global population.
The report sets its “best estimate” of the population facing hunger at 673 million people, which represents a decrease of 15 million people compared to the previous year.
However, the report notes that the progress made in reducing hunger worldwide has been uneven, as seen in the chart above.
There were improvements in south-west and southern Asia, as well as Latin America, but a continuing rise in hunger in much of Africa and western Asia.
The report also finds that around 2.3 billion people were “moderate or severely food insecure” in 2024, noting that this represents an increase of 683 million more people than when the SDGs was launched a decade ago.
The report projects that by 2030 around 512 million people could face chronic hunger, with 60% of the world’s undernourished people located in Africa.
It highlights that achieving the goal of eliminating hunger by 2030 will be an “elusive target”.
The report warns that the “deteriorating food insecurity” in territories and countries currently affected by humanitarian crises – such as the Gaza Strip, South Sudan, Sudan, Yemen and Haiti – may not be fully reflected in its current estimates.
2. The cost of a healthy diet increased around the world The number of people around the world who were unable to afford a healthy diet (left) from 2017-24. The cost of a healthy diet per person, per day in purchasing power parity dollars (right) for the world (red), Africa (cyan), Asia (blue), Europe (light blue), Latin America and the Caribbean (dark blue), North America (dark grey) and Oceania (light grey). Credit: Carbon Brief, based on the UN State of Food Security and Nutrition in the World report (2025)The report finds that the cost of a “healthy” diet rose during 2023 and 2024.
It defines a “healthy” diet as one that comprises a “variety of locally available foods that meet energy and most nutrient requirements”. A healthy diet should be diverse, adequate and balanced, while maintaining moderation in consumption of food related to poor health outcomes, the report says.
In 2019, a healthy diet cost, on average, 3.30 purchasing power parity (PPP) dollars per person, per day. (Purchasing power parity is a type of currency conversion, based on the cost of goods in different locations, that allows one to compare the purchasing power of different currencies.)
By 2024, increasing food prices had driven this cost up to 4.46 PPP dollars, the report says.
At the same time, the report finds that the proportion of the population unable to afford a healthy diet has decreased every year since 2017, with the exception of 2020. For example, in 2020, the number of people worldwide who could not afford healthy food was 2.9 billion, which fell to 2.6 billion in 2024.
This is due to the economic recovery following the Covid-19 pandemic, which led to an increase in incomes that outstripped the rise in food prices, the report says.
The chart above shows how the global population was unable to afford a healthy diet each year from 2017-24 (left) and the average cost of a healthy diet, in PPP dollars per person, per day (right, red). The right-hand chart also shows the cost in each of six regions: Latin America and the Caribbean (dark blue), Asia (blue), Africa (cyan), Europe (light blue), Oceania (light grey) and North America (dark grey).
However, not all regions experienced the same economic recovery, it adds.
Asia, as a whole, saw the largest decrease in the unaffordability of healthy food – with the proportion of people unable to afford a healthy diet falling from 35% in 2019 to 28% in 2024. In contrast, the unaffordability of healthy diets increased “substantially” in Africa, with two-thirds of the population unable to afford healthy diets in 2024.
The rest of the world’s regions – with the exception of Oceania – saw a “marginal” decrease in the unaffordability of healthy food in recent years, the report says.
There are significant differences in affordability according to national incomes.
In low-income countries, the number of people unable to afford a healthy diet “has been steadily increasing since 2017”, says the report. This is attributed to a recent halt in economic growth and a sharp rise in food prices.
In lower-middle-income countries, that number decreased from 2020 to 2024, mainly due to improvements in affordability in India.
Conversely, in upper-middle- and high-income countries, the number of people unable to afford healthy food has been declining since 2020.
The report concludes that “people who are unable to afford even a least-cost healthy diet are likely experiencing some level of food insecurity”.
3. Food price inflation outstripped general inflation over 2019-25 Consumer price index (blue) and food consumer price index (red) from 2015-25, using 2015 as a reference year. Credit: Carbon Brief, based on the UN State of Food Security and Nutrition in the World report (2025)The report finds that food price inflation has “significantly” outstripped general inflation over the past five years. Median global food price inflation rose from 2.3% in December 2020 to 13.6% in January 2023.
The chart above shows consumer price index (blue) – which includes price changes to all of the items a household typically consumes – and the consumer food price index (red) over 2015-25, with 2015 taken as the reference year.
The highest rates of inflation occurred in low-income countries, with several countries experiencing “hyperinflation”, including inflation levels above 350%. The report explains that most households in low-income countries source much of their food from local markets, which are more vulnerable to price shocks.
The authors attribute the heightened inflation to a combination of factors that includes the Covid-19 pandemic, the war in Ukraine and shifting monetary policy – from lowering interest rates and launching fiscal support at the beginning of the pandemic to raising interest rates to combat surging prices.
According to the report, previous food-price shocks – such as the one that occurred during the 2008 global financial crisis – were “predominantly” driven by supply, while the current surging inflation was driven initially by demand.
Supply-side shocks occur when production or distribution of food are disrupted by external factors, resulting in a “steep and prolonged rise in food prices”. Supply-side shocks create “persistent inflationary pressures”, the report says.
Demand-side shocks – a “sudden and unexpected increase in consumer demand for food products” – are often due to economic growth and changes in consumption patterns. (The report cites as an example the Covid-19 pandemic, which led to a “surge” in demand for food at home.) Demand-side shocks are characterised by rapid increases in price, but do not typically have a long-term impact.
In addition to the global factors driving food inflation, localised shocks – such as extreme weather events – impacted inflation on sub-national and national scales, by destroying crops, disrupting supply chains and suppressing household incomes.
Since 2020, the report says, 139 out of 203 countries have faced cumulative food price inflation above 25%, with 49 countries experiencing cumulative food inflation higher than 50%. It warns:
“Such prolonged food price pressures risk undermining household coping capacities and worsening food insecurity.”
According to the report, food price rises of 10% are associated with a 3.5% rise in “moderate or severe” food insecurity, with women “disproportionately affected”.
It also notes that food price inflation has previously been found to have “detrimental effects on child nutrition”, particularly among vulnerable populations.
4. Gas price shocks contributed to high commodity prices Contribution of food price shocks (left) and food and energy price shocks (right) to global commodity food prices, from 2019-25. Overall fluctuations in food commodity prices are shown in dark blue on both charts. Credit: Carbon Brief, based on the UN State of Food Security and Nutrition in the World report (2025)Rising food prices were amplified by rising energy costs over the past several years, the report says.
It points out that oil and gas are “key input[s] in agriculture production – from fertiliser manufacturing through to transportation”.
(Nitrogen-based fertilisers are typically produced using fossil gas as an input. The process of manufacturing them is an energy-intensive one – accounting for about 1% of all global energy usage.)
The report cites two “waves” of shocks that “largely shaped” the changes in agricultural commodity prices over 2020-22.
The first wave, it says, occurred early in the Covid-19 pandemic as food supplies contracted due to supply-chain disruptions, as well as “precautionary trade restrictions and increased stockpiling”.
Global energy markets were further “destabilised” by the second shockwave – Russia’s invasion of Ukraine in February 2022. Prior to the outbreak of the war, Russia was the third-largest producer of oil and the second-largest producer of fossil gas in the world.
The war resulted in “significant price increases and heightened volatility”, which translated into higher production costs economy-wide, the report says.
The initial surge at the beginning of the pandemic contributed about 15 percentage points to global food inflation, while the war in Ukraine added 18 percentage points, the report says.
The charts above show global food price inflation (black lines) over 2019-25. The blue line in the left panel shows the contribution of “food price shocks”, such as the disruption of the Black Sea trade corridor and the decline in fertiliser exports from Russia. In the right panel, the red line shows the contribution of both food price and energy price shocks to food inflation.
According to the report, the rise in agricultural and energy commodity prices account for nearly half of food price inflation in the US and more than one-third of food price inflation in the Euro area during peak inflation over the past few years.
It adds that the remaining inflation is explained by several other factors, “including rising labour costs, exchange rate fluctuations and pricing behaviour along the supply chain”.
5. Fertiliser prices have remained high following Russia’s invasion of Ukraine Monthly price of phosphate rock (blue), diammonium phosphate fertiliser (dark red) and triple superphosphate fertiliser (light red) from 1970-2025. Credit: Carbon Brief, based on the UN State of Food Security and Nutrition in the World report (2025)The report notes that Russia’s invasion of Ukraine in February 2022 upended global fertiliser markets due to economic sanctions against Russia and Belarus – two of the world’s largest fertiliser exporters.
In 2020, Russia exported 14% of globally traded urea, the most commonly used nitrogen fertiliser. Belarus and Russia combined account for more than 40% of traded potash, a key potassium fertiliser.
While many of the sanctions against Russia following the outbreak of the war specifically omitted fertilisers and agricultural commodities, the report notes that restrictions on banking and trade increased the “cost of doing business” and restricted the ability of countries to purchase food and fertilisers from Russia.
However, the report points out, global potassium fertiliser prices were already on the rise prior to Russia’s invasion of Ukraine, due to export restrictions on fertilisers from China.
Similar trade measures on fertilisers – both export restrictions and import tariffs – have “played a role” in price spikes during previous episodes of global food price crises, including in 2007-08 and 2011-12, the report says.
The report looks specifically at phosphate fertilisers, noting that those prices have “historically been shaped by both long-term structural trends and short-term shocks”. These factors include trade restrictions, energy costs, geopolitical tensions and imbalances in supply and demand.
The chart above shows the monthly price of phosphate rock (blue), diammonium phosphate (dark red) and triple superphosphate (light red) from 1970 to 2025.
(Phosphate rock is the raw material used to manufacture most phosphate-based fertilisers, while diammonium phosphate and triple superphosphate are two commonly used phosphate fertilisers.)
Export restrictions were “critical factors” in driving the three major historical phosphate price spikes highlighted in the chart – in 1974, 2008 and 2021-22.
Given the small number of countries that produce phosphate fertilisers – their production is highly concentrated in China, the US, India, Russia and Morocco – these actions “exacerbat[e] global shortages”, the report says.
The report also points out that the concentration of agricultural markets – including the fertiliser market – is a “systemic issue that undermines efficiency and affordability” in both low- and high-income countries.
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DeBriefed 25 July 2025: World court delivers climate ‘turning point’; Renewables ‘unstoppable’; Antarctica’s oldest ice examined
Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.
POLLUTERS ‘ACCOUNTABLE’: The UN’s highest court has told “wealthy” countries “they must comply with their international commitments to curb pollution or risk having to pay compensation to nations hard hit by climate change”, reported Reuters. The International Court of Justice (ICJ) issued a much-awaited advisory opinion that small island states have described as a “legal stepping stone to make big polluters accountable”, the newswire added.
‘INHERENT RIGHT’: The Associated Press said that, during a two-hour hearing to present the unanimous opinion, Japanese judge Yuji Iwasawa told the court that the “human right to a clean, healthy and sustainable environment is…inherent in the enjoyment of other human rights”. The newswire said activists described this as a “turning point in international climate law”.
‘LEGAL WEIGHT’: The Times noted that the “view is non-binding on governments, including the [UK], and the US does not recognise the court’s jurisdiction”. However, the “ICJ’s advisory opinions carry great legal weight and are seen to contribute to the clarification of international law”, the newspaper added. Carbon Brief has just published an in-depth Q&A on what the opinion means for climate change.
Renewables ‘breakthrough’BRINK OF BREAKTHROUGH: UN secretary-general António Guterres said on Tuesday that the “world is on the brink of a breakthrough in the climate fight and fossil fuels are running out of road”, the Guardian reported, as two new reports were published illustrating the growing dominance of renewable energy. In his online speech, Guterres said the global energy transition is now “unstoppable” due to “smart economics”.
RENEWABLES ‘CHEAPER’: The first of the new reports, from the International Renewable Energy Agency (IRENA), said that around 90% of renewable power projects globally are now cheaper than fossil fuel alternatives, Reuters said. The second, from the UN drawing on data from multiple international agencies, found that renewables made up 92.5% of all new electricity capacity additions and 74% of electricity generation growth in 2024, the Financial Times reported. Carbon Brief pulled out five key takeaways from both reports.
Around the world- IN DANGER: The Trump administration has “drafted a plan to repeal a fundamental scientific finding”, known as the “endangerment finding”, that “gives the US government its authority to regulate greenhouse-gas emissions and fight climate change”, reported the New York Times.
- EU-CHINA SUMMIT: The EU and China have “committed to leading the world in the fight against climate change” in a joint statement released on Thursday following a meeting between the two superpowers, Bloomberg said. Carbon Brief’s China Briefing newsletter provided more details.
- JAPAN EYES NUCLEAR: A Japanese utility has become the first since the Fukushima nuclear disaster 14 years ago to take steps towards building a new reactor, reported Channel News Asia.
- SHELL QUITS INITIATIVE: Shell and other fossil-fuel companies have “abandoned” a six-year-long attempt to define a net-zero emissions strategy “after being told that such a standard would require them to stop developing new oil and gas fields”, according to the Financial Times.
- FLASH FLOODS: Ongoing flash flooding in Pakistan has killed at least 266 people over the past month, the Hindu reported.
The temperature in some parts of Iran this week – as authorities asked people to limit drinking water amid an ongoing drought crisis, reported the Guardian.
Latest research- Climate change is creating “new vulnerabilities” for pandemics | Carbon Brief
- South American lands stewarded by “Afro-descendant” people coincide with areas with “high biodiversity” and are associated with a 29-55% reduction in forest loss, compared to control sites | Communications Earth & Environment
- The “true price” of solar geoengineering is “much higher than its modest technical costs would indicate” | npj Climate Action
(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)
CapturedNew research covered by Carbon Brief this week found that one in three people in informal settlements in the global south live in floodplains and are at risk of a “disastrous flood”. The chart above draws on data from the study, published in Nature Cities, to illustrate where in the world has the highest number of “slum residents” living in floodplains.
Spotlight Antarctica’s oldest ice arrives in UKCarbon Brief recently visited British Antarctic Survey scientists responsible for uncovering the secrets of Antarctica’s oldest ice.
Standing in a freezer in Cambridge – with a -25C chill licking at his nostrils – British Antarctic Survey (BAS) lab manager Jack Humby excitedly opens up an unassuming polystyrene box.
Using his bare hands, he pulls out its contents. Long square-shaped sections of crystal clear ice – wrapped in plastic labelling which way is up – are revealed.
Little about the appearance of the ice gives away that it is at least 1.2m years old.
It has journeyed to the BAS headquarters on the outskirts of Cambridge from an ice core drilling camp in East Antarctica.
British Antarctic Survey lab manager Jack Humby holds 1.2m-year-old Antarctic ice. Credit: Daisy DunneIn January, scientists at the camp vertically drilled a 2,800m-long ice core, with on-site tests revealing it was likely to be at least 1.2m years old. The ice was then flown to a nearby port and shipped to Europe aboard the Italian icebreaker Laura Bassi.
The ice was drilled as part of the Beyond Epica Oldest Ice project, a large-scale field operation involving multiple research teams and laboratories across Europe.
‘One shot’Owing to its specialist equipment and research expertise, BAS has been tasked with analysing the ice to reveal its secrets.
Though not visible to the human eye, the ice contains organic compounds and tiny pockets of air from periods stretching back hundreds of thousands of years.
Over the next seven weeks, the research team at BAS will work around the clock to analyse these features. However, in order to do so, they will have to melt the ice.
Dr Liz Thomas, head of the ice cores team at BAS, told journalists:
“It’s a huge responsibility because this is a one shot. Given how much effort has gone into drilling these cores, we have to get this absolutely right.”
To conduct their analysis, the team plan to use a gold-plated instrument to melt the square-shaped sections of ice being stored in the freezer room.
The meltwater will then be piped into a specially designed lab next door, which contains millions of pounds worth of analysis equipment, according to Humby.
Climates pastThe analysis will help scientists work out how old the ice actually is. Though initial tests suggest it is at least 1.2m years old, but the team believe it could be up to 1.5m years old or even older.
It will also enable researchers to paint a more detailed picture of Earth’s past climates.
In turn, this could inform scientists’ understanding of how large swings in temperature in the past have affected various parts of the Earth climate system, including its ice sheets and ecosystems.
Ultimately, this could help researchers to make more informed projections about the likely impacts of human-caused climate change, Thomas explained:
“As climate scientists, it’s our job to provide as much information as we can. What we’re relying on to understand the next steps is climate models. They are fantastic, but they’re only as good as the information we put into them. That really is the justification for looking back in time.”
Watch, read, listenCOP30 LOOMS: A long-read in the Brazilian culture magazine Piauí examined the fraught road that the nation faces to host the next UN climate summit in November.
ARCTIC ‘MELTING POINT’: In Nature Communications, researchers recounted how the Arctic island of Svalbard is facing a “dramatic shift” to high air temperatures and rainfall in the depths of winter.
STUDENT VICTORY: The Guardian spoke to a group of students from the Pacific islands who started the campaign for the world’s top court, the ICJ, to take on the issue of climate change.
Coming up- 23-31 July: COP15 of the Ramsar Convention on Wetlands, Victoria Falls, Zimbabwe
- 30 July: International Energy Agency electricity mid-year update
- 30 July: Advancing the implementation of the Chilean framework Law on Climate Change, Santiago, Chile
- Boston Globe, climate science and environment reporter | Salary: Unknown. Location: Boston, US
- Science Museum London, curator of climate and earth sciences | Salary: £41,770. Location: London
- Netflix, manager, sustainability standards and partnerships | Salary: Unknown. Location: Amsterdam, Netherlands
DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to debriefed@carbonbrief.org.
This is an online version of Carbon Brief’s weekly DeBriefed email newsletter. Subscribe for free here.
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ICJ: What the world court’s landmark opinion means for climate change
The highest court of the UN has issued a landmark “advisory opinion” stating that nations can be held legally accountable for their greenhouse-gas emissions.
Recognising the “urgent and existential threat” facing the world, the International Court of Justice (ICJ) concluded that those harmed by human-caused climate change may be entitled to “reparations”.
Their opinion largely rests on the application of existing international law, clarifying that climate “harms” can be clearly linked to major emitters and fossil-fuel producers.
The case, which was triggered by a group of Pacific island students and championed by the government of Vanuatu, saw unprecedented levels of input from nations.
In a unanimous decision issued on 23 July, the 15 judges on the ICJ concluded that the production and consumption of fossil fuels “may constitute an internationally wrongful act attributable to that state”.
The opinion also says that limiting global warming to 1.5C should be considered the “primary temperature goal” for nations and, to achieve it, they are obliged to make “adequate contributions”.
While the ICJ opinion is not binding for governments, it could have significant influence as vulnerable groups and nations push for stronger climate action or seek compensation in court.
Below, Carbon Brief explains the most important aspects of the ICJ’s 133-page advisory opinion and speaks to legal experts about its implications.
- How did this case come about?
- How has the case been decided?
- What does the ICJ say about climate science?
- What does the ICJ say about countries’ climate obligations?
- What does it say about the legal consequences of breaches?
- What does it say about historical responsibility and reparations?
- What does it say about the Paris Agreement and 1.5C?
- What does it say about fossil fuels?
- What does it say about countries lost to sea level rise?
- What will it mean for other climate litigation?
- How are people reacting to the court’s opinion?
The case stems from a campaign led by 27 students from the University of the South Pacific in Fiji.
In 2019, they established a youth-led grassroots organisation – dubbed the Pacific Island Students Fighting Climate Change (PISFCC) – and began efforts to persuade the leaders of the Pacific Islands Forum to take the issue of climate change to the world’s top court.
PISFCC joined forces with other youth organisations from around the world in 2020, lobbying state representatives to take action.
In 2021, the government of Vanuatu announced that it would lead efforts to gain an “advisory opinion” from the ICJ. It worked to engage with the Pacific island community first, to build a “coalition of like-minded vulnerable countries”, reported Climate Home News.
Following on from this work, Vanuatu received a unanimous endorsement for its efforts from the 18 members of the Pacific Island Forum. It continued to work diplomatically, engaging in discussions across Europe, Asia, Africa and Latin America to encourage other countries to join the effort.
After three rounds of consultations with other states, the resolution was put before the UN general assembly with the backing of 105 sponsor countries.
Finally, on 29 March 2023, the assembly unanimously adopted the resolution formally requesting an “advisory opinion” from the ICJ.
The resolution posed two questions for the ICJ. In answering these questions, it asked the court to have “particular regard” to a range of laws and principles, including the UN climate regime and the universal declaration on human rights.
Questions asked by the UN general assembly the ICJ. Source: ICJ.First, the resolution asked what are the legal obligations of states under international law to “ensure the protection of the climate system”.
Second, it asked what are the legal consequences flowing from these obligations if states, by their “acts or omissions”, have caused “significant harm to the climate”.
The resolution asked for the court to consider, in particular, states that are “specially affected” or are “particularly vulnerable” to the impacts of climate change.
It also pointed to “peoples and individuals of the present and future generations affected by the adverse effects of climate change”.
Therefore, the advisory opinion issued this week by the ICJ, in response to these questions, is the culmination of a years-long process.
Although the opinion is not binding on states, it is binding on UN bodies and is likely to have far-reaching legal and political consequences at a national level.
How has the case been decided?The ICJ was tasked with interpreting international law and arriving at an advisory opinion. While its legal advice will, therefore, not be binding for nations, it will be binding for other UN bodies.
This two-year process involved the judges defining the scope and meaning of the broad questions put to them by the UN general assembly. (See: How did the case come about?)
They then considered which international laws and principles were relevant for these questions.
Among the relevant laws identified were the three UN climate change treaties – the UNFCCC, the Kyoto Protocol and the Paris Agreement.
They also considered various other treaties covering biodiversity, ozone depletion, desertification and the oceans, as well as legal principles such as the principle of “prevention of significant harm to the environment”.
The ICJ’s process has also seen nations and international groups, such as the Organisation of the Petroleum Exporting Countries (Opec), offer their views on the case.
These groups had the opportunity to feed into the judges’ deliberations over several stages, including two sets of written submissions, followed by oral statements to the court.
In total, the court received 91 written statements, a further 107 oral statements – delivered at the Hague in December 2024 – and 65 responses to follow-up questions by the judges.
This is the “highest level of participation in a proceeding” in the court’s history, according to the ICJ. Some nations, including island states such as Barbados and Micronesia, appeared before the court for the first time ever.
These contributions demonstrated broad agreement among nations that climate change is a threat and that emissions should be cut in order to meet the objectives of the Paris Agreement.
But there were major divergences on the breadth and nature of obligations under international law to act to limit global warming, as well as on the consequences of any breaches, as specifically being addressed by the ICJ.
Overall, the main divisions were between high-emitting nations trying to limit their climate obligations and low-emitting, climate-vulnerable nations, who were pushing for broader legal obligations and stricter accountability for any breaches.
Specifically, “emerging” economies such as China and Saudi Arabia, along with historical high-emitters such as the UK and EU, argued that climate obligations under international law should be defined solely by reference to the UN climate regime.
In contrast, vulnerable nations said that wider international law should also apply, bringing additional obligations to act – and the potential for legal consequences, including reparations.
This is a departure from UN climate talks, where the main divide tends to be between “developed” and “developing” countries – with the latter encompassing both high- and low-emitting nations.
In an unusual move, the ICJ judges also organised a private meeting in November 2024 with scientists representing the Intergovernmental Panel on Climate Change (IPCC).
Among those present were IPCC chair Prof Jim Skea and eight other climate scientists from various countries and with different areas of expertise.
A statement issued by the ICJ said this was an effort to “enhance the court’s understanding of the key scientific findings which the IPCC has delivered”.
Presiding ICJ judge Yuji Iwasawa, second from right, speaks at a hearing to deliver the advisory opinion. Credit: Associated Press / Alamy Stock PhotoOn 23 July 2025, after some seven months of deliberation, the ICJ issued a unanimous opinion in response to the UN general assembly’s request.
This is only the fifth time the court has delivered a unanimous result, according to the ICJ, after nearly 88 years in operation and 29 opinions.
(In addition to the unanimous opinion of the full court, several of the ICJ judges also issued their own declarations and opinions, individually or in small groups.)
What does the ICJ say about climate science?When considering the “context” for the issuing of the advisory opinion on climate change, the court provides information on the “relevant scientific background”.
This was drawn from reports by the IPCC, which the court says “constitute the best available science on the causes, nature and consequences of climate change”.
It comes after ICJ judges held a private meeting with IPCC scientists in 2024. (See: How has the case been decided?)
The advisory opinion states that it is “scientifically established that the climate system has undergone widespread and rapid changes”, continuing:
“While certain greenhouse gases [GHGs] occur naturally, it is scientifically established that the increase in concentration of GHGs in the atmosphere is primarily due to human activities, whether as a result of GHG emissions, including by the burning of fossil fuels, or as a result of the weakening or destruction of carbon reservoirs and sinks, such as forests and the ocean, which store or remove GHGs from the atmosphere.”
It continues that the “consequences of climate change are severe and far-reaching”, listing impacts including the “melting of ice sheets and glaciers, leading to sea level rise”, “more frequent and intense” extreme weather events and the “irreversible loss of biodiversity”. The document adds:
“These consequences underscore the urgent and existential threat posed by climate change.”
The advisory opinion further adds that the “IPCC notes that adaptation measures are still insufficient” and that “limits to adaptation have been reached in some ecosystems and regions”.
On the need to address rising emissions, the document quotes the IPCC directly, saying:
“According to the panel, climate change is a threat to ‘human well-being and planetary health’ and there is a ‘rapidly closing window of opportunity to secure a liveable and sustainable future for all’ (very high confidence). It adds that the choices and actions implemented between 2020 and 2030 ‘will have impacts now and for thousands of years’.”
It adds that the “IPCC has also concluded with ‘very high confidence’ that risks and projected adverse impacts and related loss and damage from climate change will escalate with every increment of global warming”.
In regards to how states should consider climate science when implementing climate policies and measures, the court says that countries should exercise the “precautionary principle”, adding:
“The court observes that where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing cost-effective measures to prevent environmental degradation.”
What does the ICJ say about countries’ climate obligations?In response to the first question on legal obligations, the ICJ says that countries have “binding obligations to ensure protection of the climate system” under the UN climate treaties.
However, the court’s unanimous opinion flatly rejects the argument, put forward by high emitters, such as the US, UK and China, that these treaties are the end of the matter.
These nations had argued that the climate treaties formed a “lex specialis”, a specific area of law that precludes the application of broader general international law principles.
On the contrary, the ICJ says countries do have legal obligations under general international law, including a duty to prevent “significant harm to the environment”, with further obligations arising under human rights law and from other treaties.
As such, the court, “essentially sided with the global south and small island developing states”, says Prof Jorge Viñuales, Harold Samuel professor of law and environmental policy at the University of Cambridge.
Moreover, the court finds that countries’ obligations extend not only to greenhouse gas emissions, but also to fossil-fuel production and subsidies, says Viñuales, who acted for Vanuatu in the case.
Speaking to Carbon Brief in a personal capacity, he says: “That is important because major producers are not necessarily major emitters and vice-versa.”
Vanuatu climate minister Ralph Regenvanu responds to the ICJ’s advisory opinion at a press conference. Credit: ZUMA Press Wire / Alamy Stock PhotoIn terms of the UN climate treaties, such as the Paris Agreement, the court affirms that these give countries binding obligations including adopting measures to mitigate greenhouse gas emissions and adapt to climate change.
Developed countries – parties listed under Annex I of the UNFCCC – have “additional obligations to take the lead in combating climate change”, the ICJ notes.
States also have a “duty” to cooperate with each other in order to achieve the objectives of the UNFCCC, acting in “good faith” to prevent harm, it adds.
Beyond the climate treaties, it says that “states have a duty to prevent significant harm to the environment”. Therefore, they must act with “due diligence” and use “all means at their disposal” to prevent activities carried out within their jurisdiction or control from causing “significant harm” to the climate system.
The court sets out the “appropriate measures” that would demonstrate due diligence, including “regulatory mechanisms…designed to achieve deep, rapid and sustained reductions” in emissions. This repeats language from the IPCC, but attaches it to countries’ legal obligations.
As with action under the climate treaties, countries’ obligations under broader international law should be taken in accordance with the principle of “common but differentiated responsibilities” it adds, a point reaffirmed throughout the advisory opinion.
Furthermore, countries have obligations to act on climate under a raft of other international agreements, covering the ozone layer, biological diversity, desertification and the UN convention on the law of the sea, the ICJ notes.
The court affirms that states that are not party to UN climate treaties must still meet their equivalent obligations under customary international law. This “addresses the unique situation of the US, but without naming it”, notes Sébastien Duyck, a senior attorney at the Center for International Environmental Law, on Bluesky.
Following his re-election last year, US president Donald Trump signed an order to pull the country out of the Paris Agreement again. As such, there is a question around how the ICJ’s opinion might apply to the US – the country that has contributed more to human-caused climate change than any other nation.
Additionally, states have obligations under international human rights law to “respect and ensure the effective enjoyment of human rights by taking necessary measures to protect the climate system and other parts of the environment”, according to the ICJ.
This follows a ruling from the European Court of Human Rights (ECHR) in 2024 that found that the Swiss government’s climate policies violated human rights, as governments are obliged to protect citizens from the “serious adverse effects” of climate change.
Announcing the opinion to the Hague, judge Iwasawa Yuji, president of the court, said:
“The human right to a clean, healthy and sustainable environment is essential for the enjoyment of other human rights.”
What does it say about the legal consequences of breaches?The second part of the advisory opinion deals with the “legal consequences” of countries causing “significant harm to the climate system and other parts of the environment”.
This refers to nations breaching their “obligations”, as defined in the first part of the opinion. (See: What does the ICJ say about countries’ climate obligations?)
Crucially, the court says that countries can, in principle, face liability for climate harms, opening the door to potential “reparations” for loss and damage. Prof Viñuales tells Carbon Brief:
“Perhaps the main take away from the opinion is that the court recognised the principle of liability for climate harm, as actionable under the existing rules.”
Prof Viñuales notes that the court says “climate justice is governed by the general international law of state responsibility, which provides solutions for the recurrent arguments levelled to escape liability for climate harm”.
Essentially, the ICJ rejects the notion that it is too difficult to hold countries accountable for climate damages.
Examples of breached obligations given by the court include failing to set out or implement climate pledges – known as nationally determined contributions (NDCs) – under the Paris Agreement, or to sufficiently “regulate emissions of greenhouse gases”.
The ICJ stresses that it is not responsible for pointing fingers at particular countries, only for issuing a “general legal framework” that countries can follow.
As part of this process, it lays out a justification for why states can be held responsible for climate change.
During the ICJ process, some countries argued that greenhouse gas emissions are not like other environmental damage, such as localised chemical pollution. They said that emissions arise from all sorts of regular activities and it is difficult to tie climate damage to specific sources.
Others argued that it is perfectly possible to attribute such damage to states that, for example, have laws to “promote fossil-fuel production and consumption”.
This is important, as the ICJ points out that attribution is necessary if an activity is to be defined as an “internationally wrongful act”. Ultimately, the court agrees that it is feasible to attribute climate damage to specific states, on a “case-by-case” basis.
Paragraph 432 of the ICJ’s advisory opinion, from the section on “questions relating to attribution”. Credit: ICJ.The court also finds that it is possible, at least in principle, to link climate disasters to countries’ emissions, though it notes that the causal links may be “more tenuous” than for localised pollution. It cites IPCC findings that climate change has amplified heatwaves, flooding and drought, stating:
“While the causal link between the wrongful actions or omissions of a state and the harm arising from climate change is more tenuous than in the case of local sources of pollution, this does not mean that the identification of a causal link is impossible.”
With this established, the court sets out what the consequences could be for countries that are deemed to have carried out “wrongful acts”.
First, the ICJ stresses that nations must meet their existing climate obligations. This means that if, for example, a government publishes an “inadequate” NDC, a “competent court or tribunal” could order it to supply one that is consistent with its obligations under the Paris Agreement.
Second, it also says that if a state is found responsible for climate damage, it must stop and ensure that it does not happen again.
States may be required to “employ all means at their disposal” to carry out this duty, according to the ICJ. In practice, the court says that this could mean governments revoking administrative or legislative acts in order to cut emissions.
In theory, this could lead to more stringent climate policies. For example, Dr Maria Antonia Tigre, director of global climate change litigation at the Sabin Centre for Climate Change Law, tells Carbon Brief:
“The ICJ made clear that the standard of due diligence is stringent and that each state must do its utmost to submit NDCs reflecting its highest possible ambition. That may strengthen pressure – political, legal and public – on states to raise their climate targets, especially before the next global stocktake.”
Finally, the ICJ opens the door for countries to seek “reparations” for climate harms from other countries.
It says these reparations could be expressed in different ways – including paying compensation or issuing formal apologies for wrongdoing.
This outcome was widely celebrated by climate justice activists and vulnerable nations, who see it as ushering in a “new era” in the fight to obtain financial compensation for climate disasters.
Harj Narulla, a barrister at Doughty Street Chambers and legal counsel for the Solomon Islands, tells Carbon Brief:
“The ICJ’s ruling has provided a legal pathway for developing states to seek climate reparations from developed States…States can bring claims for compensation or restitution for all climate-related damage. This includes claims for loss and damage, but importantly extends to any harm suffered as a result of climate change.”
What does it say about historical responsibility and reparations?One of the most significant parts of the ICJ opinion is the assertion that nations and “injured individuals” can seek “reparations” for climate damage.
This ties in with a long and contentious history of climate-vulnerable nations in the global south seeking compensation from high-emitting nations.
The notion of “climate reparations” has often been linked to developing countries pushing for so-called “loss and damage” finance in UN climate negotiations, including the – ultimately successful – fight for a “loss-and-damage fund”.
However, the US and other big historical emitters have ensured that any progress on loss-and-damage funding has not left them legally accountable for their past emissions.
The Paris Agreement states explicitly that its inclusion of loss and damage “does not involve or provide a basis for any liability or compensation”.
Crucially, the ICJ opinion makes it clear that such language does not override international law and states’ responsibilities to provide “restitution”, “compensation” and “satisfaction” to those harmed by climate change.
Danilo Garrido Alves, a legal counsel for Greenpeace International, tells Carbon Brief that this means loss-and-damage finance is not a replacement for reparations:
“If a state contributes to the loss and damage fund and at the same time breaches obligations…that does not mean they are off the hook.”
Legal experts, including Prof Viñuales, tell Carbon Brief that this outcome is not surprising, given its grounding in international law. He says:
“It is the correct understanding of international law, but, in law, progress often takes the form of moving from the implicit to the explicit and that’s what the court did.”
Paragraph 420 of the ICJ’s advisory opinion, from the section on “applicable law”. Credit: ICJ.Nevertheless, the outcome could have major implications for climate politics and lead to a wave of new climate litigation. Dr Tigre, at the Sabin Centre for Climate Change Law, tells Carbon Brief:
“[It] could shift the conversation from voluntary climate finance to legal obligations to repair harm, particularly for vulnerable communities and states already suffering loss and damage.”
Notably, the court says that while some states are “particularly vulnerable” to climate change, international law “does not differ” depending on such status. This means that, in principle, all nations are “entitled to the same remedies”.
As for individuals or groups taking legal action for both “present and future generations”, the ICJ notes that their ability to do so does not depend on rules around “state responsibility”. Instead, they would depend on obligations being breached under “specific treaties and other legal instruments”.
The ICJ says that reparations would be determined on a case-by-case basis, noting that the “appropriate nature and quantum of reparations…depends on the circumstances”. It also notes that:
“In the climate change context, reparations in the form of compensation may be difficult to calculate, as there is usually a degree of uncertainty.”
The question of precisely which nations will be liable for paying climate reparations is also predictably complex. Much of this discussion centres around responsibility for emissions, both currently and in the past.
Under the Paris Agreement, “developed” countries – a handful of nations in the global north – are obliged to provide climate finance to “developing” countries, which includes major emitters such as China.
In ICJ submissions, major emitters and fossil-fuel producers categorised as “developing” under the UN system stressed their low historical emissions. Some developing countries blamed climate change on a small group of “developed states of the global north”.
For their part, some countries with high historical emissions argued that it is difficult to assign responsibility for climate change.
However, the ICJ concludes that this is not the case. It says it is “scientifically possible” to determine each state’s contribution, accounting for “both historical and current emissions”.
Paragraph 429 of the ICJ’s advisory opinion, from the section on “questions relating to attribution”. Credit: ICJ.Therefore, while the court explicitly avoids identifying the countries responsible for paying reparations, it makes clear that historical responsibility should be accounted for when considering whether states have met their climate obligations.
Finally, the court also says that “the status of a state as developed or developing is not static” and that it depends on the “current circumstances of the state concerned”.
This is notable, given that the current definitions of these terms – which determine who gives and receives climate finance – are based on definitions from the early 1990s.
What does it say about the Paris Agreement and 1.5C?The advisory opinion offers clear guidance on the Paris Agreement and its aim to limit global temperature rise to “well-below” 2C by 2100, with an aspiration to keep warming below 1.5C.
It says that limiting temperature increase to 1.5C should be considered countries’ “primary temperature goal”, based on the court’s interpretation of the Paris Agreement.
Excerpt from ICJ’s advisory opinion on the obligations of states in respect of climate change. Credit: ICJ.The court adds that this interpretation is consistent with the Paris Agreement’s stipulation that efforts to tackle climate change should be based on the “best available science”.
(In 2018, four years after the Paris Agreement, a special report from the IPCC spelled out how limiting global warming to 1.5C rather than 2C could, among other things, save coral reefs from total devastation, stem rapid glacier loss and keep an extra 420 million people from being exposed to extreme heatwaves.)
Following this, the advisory opinion also makes it clear that countries are not just encouraged – but “obliged” – to put forward climate plans that “reflect the[ir] highest possible ambition” to make an “adequate contribution” to limiting global warming to 1.5C.
(The climate plans that countries submit to the UN under the Paris Agreement are known as “nationally determined contributions” or “NDCs”.)
Moreover, contrary to the arguments of some countries, the advisory opinion states:
“The court considers that the discretion of parties in the preparation of their NDCs is limited.
“As such, in the exercise of their discretion, parties are obliged to exercise due diligence and ensure that their NDCs fulfil their obligations under the Paris Agreement and, thus, when taken together, are capable of achieving the temperature goal of limiting global warming to 1.5C.”
Dr Bill Hare, a veteran climate scientist and CEO of research group Climate Analytics, noted that the court’s stipulations on the 1.5C and NDCs represent a “fundamental set of findings”. In a statement, he said:
“The ICJ finds that the Paris Agreement’s 1.5C limit is the primary goal because of the urgent and existential threat of climate change and that this requires all countries to work together towards the highest possible ambition to limit warming to this level.
“All countries have an obligation to put forward the highest possible ambition in their NDCs that represent a progression over previous NDCs; it is not acceptable to put forward a weak NDC that does not align with 1.5C.
“The ICJ points to potential for serious legal consequences under customary international law if countries do not put forward targets aligned to 1.5C.”
The court also notes that the concept of equity is essential to the Paris Agreement and other climate legal frameworks, commonly referred to by text noting that countries have “common but differentiated responsibilities and respective capabilities”.
Significantly, it adds that the Paris Agreement differs from other climate frameworks by also stating that these responsibilities and capabilities should be considered “in the light of different national circumstances”.
The advisory opinion continues:
“In the view of the court, the additional phrase does not change the core of the principle of common but differentiated responsibilities and respective capabilities; rather, it adds nuance to the principle by recognising that the status of a state as developed or developing is not static. It depends on an assessment of the current circumstances of the state concerned.”
The verdict comes after debate – considered highly controversial by many – about whether “emerging” economies, such as China and India, should be considered “developing countries” at climate summits.
What does it say about fossil fuels?One of the most eye-catching paragraphs of the advisory opinion relates to its verdict on fossil fuels.
In a section labelled “determination of state responsibility in the climate change context”, the court specifically addresses countries’ obligations when it comes to producing, using and economically supporting fossil fuels. (See below).
Excerpt from ICJ’s advisory opinion on the obligations of states in respect of climate change. Credit: ICJ.The court says that fossil-fuel production, consumption, the granting of exploration licences or the provision of subsidies “may constitute an internationally wrongful act” attributable to the state or states involved.
It comes after multiple analyses have concluded that any new oil and gas projects globally would be “incompatible” with limiting global warming to 1.5C.
Speaking to Carbon Brief, climate law expert Prof Jorge Viñuales notes that the clear mention of fossil fuels comes despite not being featured in the questions posed to the court:
“The request characterised the conduct to be assessed by reference to emissions, so the court could have stayed there. Yet, the relevant conduct was expanded to production and consumption of fossil fuels, including subsidies.”
Though the advisory opinion is not legally binding on countries, it could influence domestic decision-making around granting permissions to new fossil fuel projects going forward, adds Joy Reyes, a policy officer at the Grantham Research Institute on Climate Change and the Environment at the London School of Economics. She tells Carbon Brief:
“Litigants can cite the advisory opinion in future climate litigation, which includes the language around fossil fuels. While not legally binding, the advisory opinion carries moral weight and authority, and can influence domestic decision-making around new fossil-fuel projects. If states and corporations fail to transition away from fossil fuels, their risk for liability increases.”
What does it say about countries lost to sea level rise?The ICJ’s advisory opinion concludes that nations’ existing maritime zones or statehood would “not necessarily” be compromised by sea-level rise resulting from climate change.
This has long been an important issue for island nations, including the Pacific states that pushed for the court’s advisory opinion (See: How did this case come about?).
Some of these nations are very low-lying and are already making preparations for a time when much of their territory is underwater.
They have been seeking assurances that they will retain territorial rights as the impacts of climate change worsen.
In its assessment of the UN Convention on the Law of the Sea (UNCLOS), the ICJ says that nations are “under no obligation to update charts or lists of geographical co-ordinates” due to sea-level rise.
This means the legal rights of states over their maritime zones – including any resources, such as minerals and fish, that are present there – would be protected.
The ICJ also states that, in its view:
“Once a state is established, the disappearance of one of its constituent elements would not necessarily entail the loss of its statehood.”
Prof Viñuales, who acted for the island nation of Vanuatu in the case, tells Carbon Brief this outcome is a “key aspect” of the opinion, adding that it is “remarkable”.
What will it mean for other climate litigation?Following the landmark advisory opinion, one of the biggest questions moving forward is what it could mean for other climate lawsuits, both domestic and international.
Advisory opinions from the ICJ are not legally binding, but the court’s summarisation of existing law carries “moral weight and authority”, according to Joy Reyes, a policy officer at the Grantham Research Institute on Climate Change and the Environment.
This is particularly relevant for states that “accept the persuasive authority of international law”, explains Dr Joana Setzer, an environmental lawyer and an associate professorial research fellow at the London School of Economics and Political Science’s Grantham Institute.
Courts in some states, such as the UK, Australia and Canada, will consult international law when interpreting domestic laws or dealing with international treaties.
Setzer explains to Carbon Brief:
“The ICJ confirms that failures to act – such as maintaining inadequate national targets, licensing new fossil fuel projects or failing to support adaptation in vulnerable countries – can engage state responsibility under international law. The court also dismissed a common defence – that a state’s emissions are ‘too small to matter’. Even small contributors can be held responsible for their share of the harm.
“Domestic climate litigation may seek to use this argument and the court’s opinion to establish greater obligation on states to address climate change at the domestic level. Courts in jurisdictions that accept the persuasive authority of international law, such as the Netherlands, could now cite this ruling in support of decisions compelling stronger climate action from governments or corporations.”
She adds that the court’s conclusion that “states are not only responsible for reducing their own emissions”, but “also have a due diligence duty to regulate private actors under their jurisdiction” could have implications. Stezer continues:
“That includes fossil-fuel companies. This has far-reaching implications: it signals that states could be in breach if they fail to control emissions from companies they license, subsidise or oversee. This will place greater pressure on states to halt any new fossil fuel projects and introduce stricter regulations on the sector.”
Climate law expert Prof Jorge Viñuales says that the opinion makes it clear that the Paris Agreement is a “serious legal instrument imposing genuine and justiciable obligations”, which is likely to have an impact on domestic lawsuits. He tells Carbon Brief:
“We can expect that to be widely litigated around the world.”
In addition, he says that the court’s opinion that countries’ legal obligations extend beyond the UN climate treaties creates a “much wider chessboard for climate litigation”. He adds:
“Last, but absolutely not least, it was important, from a climate justice perspective, to hear from the court that one cannot simply game the climate change regime without legal consequences. Those consequences may take time to materialise, but they very likely will.”
How are people reacting to the court’s opinion?The ICJ’s advisory opinion was welcomed by many governments, NGOs and legal experts as a “groundbreaking” legal milestone and a “moral reckoning”.
However, the European Commission and France were among those responding to the court’s opinion more cautiously, while opposition politicians in the UK were hostile to the ICJ’s findings.
A Chinese government spokesperson, meanwhile, said the opinion was in line with China’s views, while the White House said the US would put itself and its interests first.
One particularly positive response came from Ralph Regenvanu, minister of climate change adaptation, meteorology and geo-hazards, energy, environment and disaster management for the Republic of Vanuatu, who commended the opinion. In a statement, he said:
“The ICJ ruling marks an important milestone in the fight for climate justice. We now have a common foundation based on the rule of law, releasing us from the limitations of individual nations’ political interests that have dominated climate action. This moment will drive stronger action and accountability to protect our planet and peoples.
Vishal Prashad, director of Pacific Islands Students Fighting Climate Change, welcomed the ICJ’s statements on what he said was the need to “urgently phase out fossil fuels…because they are no longer tenable”. He continued:
“For small island states, communities in the Pacific, young people and future generations, this opinion is a lifeline and an opportunity to protect what we hold dear and love. I am convinced now that there is hope and that we can return to our communities saying the same. Today is historic for climate justice and we are one step closer to realising this.”
The reaction from developed countries was more muted, with France stating that the “landmark opinion will be studied very closely”. It reaffirmed its “unwavering commitment to the ICJ”.
A spokesperson for the European Commission, Anna-Kaisa Itkonen, told the media that the opinion “confirms the magnitude of the challenge we face and the importance of climate action”. She added that the commission would examine what the opinion “precisely implies” and noted that the EU’s emissions are behind those of China, the US and India.
A spokesperson for China’s foreign ministry said in a regular press conference that the ICJ opinion was “of positive significance to maintaining and advancing international climate cooperation”.
They added that, in their view, the court reinforced the “long-standing stance” of China, whereby developed countries should “take the lead” in tackling climate change:
“We noted that the ICJ’s advisory opinion pointed out that the UNFCCC system is the principal legal instruments regulating the international response to the global problem of climate change and confirmed that the principle of common but differentiated responsibility, the principle of sustainable development and the principle of equity are applicable as guiding principles for the interpretation and application of relevant international law.”
In response to the opinion, a spokesperson for the White House told Reuters:
“As always, President Trump and the entire administration is committed to putting America first and prioritising the interests of everyday Americans.”
Many within the wider international community also welcomed the advisory opinion. For example, Mary Robinson, a member of the Elders and the first woman president of Ireland and former UN high commissioner for human rights, called the opinion a “powerful new tool to protect people from the devastating impacts of the climate crisis – and to deliver justice for the harm their emissions have already caused”.
António Guterres, secretary-general of the UN said in a statement that the ICJ had issued a “historic” opinion. He added:
“They made clear that all States are obligated under international law to protect the global climate system. This is a victory for our planet, for climate justice and for the power of young people to make a difference. Young Pacific Islanders initiated this call for humanity to the world. And the world must respond.”
Charities such as Amnesty International, Earthjustice and Greenpeace hailed the “landmark moment for climate justice and accountability”.
Tasneem Essop, executive director of Climate Action Network International, said that “the era of impunity is over”, adding that the ruling “could not have come at a better time” ahead of the upcoming COP30 summit.
Within the media, a lot of coverage focused on the potential that nations might have to pay reparations for breaching their climate obligations.
In the Guardian, Harj Narulla, barrister and leading global expert on climate litigation at Doughty Street Chambers and the University of Oxford, discusses what the ICJ’s advisory opinion could mean for Australia and other major polluters in a “new era of climate reparations”.
In its news coverage, the Daily Telegraph says that the UN “has opened the door to Britain being sued over its historic contribution to climate change”. It adds that the opposition Conservative and Reform parties “both rejected the ruling”.
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Chemical Mismatch: Value Chain Under Strain
Many credible commentators, such as the International Energy Agency (IEA), BloombergNEF, DNV, McKinsey, and bp, expect demand for crude and natural gas liquids to peak before 2030.[1] And yet, Carbon Tracker’s most recent holistic assessment of oil and gas companies, outlined in Paris Maligned III, found that the industry by and large is planning to grow output in the coming years. The hope is that the growth in petrochemical demand will help offset most of the oil demand that will be lost to electric vehicles and renewables. Indeed, some oil and gas companies are even planning to expand their downstream operations to produce petrochemicals themselves.
Meanwhile, leading chemical producers have pledged commitment to Paris-aligned decarbonisation pathways, aiming to meet regulatory requirements, technological needs, and investor expectations. Key to that will be replacing fossil-derived feedstocks with alternative materials, electrifying operations, achieving energy efficiencies, and transitioning to renewable energy sources.
These differing interests create a structural tension in the petrochemical value chain, with energy suppliers seeking to sell more of their products to an industry that seeks to wean itself off them. This note draws on recent research from Carbon Tracker and Planet Tracker to highlight this structural tension and the associated risks for each of the two industries.
ChemicalsThe chemical industry stands at a critical inflection point. While companies are increasingly signalling their intention to align with climate goals, progress remains uneven and, in many cases, insufficient to meet Paris-aligned decarbonisation pathways. Planet Tracker’s recent benchmark of eight chemical companies[2], Lessons in Chemistry, found significant gaps in ambitions around emissions performance, capital allocation, and governance strategies.
Structural challenges exacerbate the problem. The chemical industry is among the most emissions-intensive sectors due to its reliance on fossil feedstocks, high-temperature production processes, and complex, long-lived assets. At the same time, pressure from policy-makers, including carbon pricing, stronger disclosure requirements, and taxonomy-based investment rules, is likely to intensify over the coming years.
In this note, we categorise the core challenges of the chemical sector’s transition under three interrelated themes: Emissions, Governance, and Resilience.
Emissions targets and performance remain weak, with disclosure concerns
On the emissions front, Planet Tracker’s analysis reveals that for seven of the eight companies assessed[3], Scope 3 accounts for 70% to 83% of their total GHG footprint, underscoring the sector’s deep ties with upstream fossil inputs and downstream product use. Four of the eight companies analysed[4] have upstream-heavy Scope 3 profiles, driven by fossil feedstock procurement, while the rest[5] exhibit downstream-heavy emissions, associated with product use and end-of-life disposal.
These emissions structures have important implications for chemicals decarbonisation pathways. For instance, electrification and clean energy are critical for the company with a high Scope 1 and 2 dependence[6]. Meanwhile, feedstock substitution is key for the four upstream-heavy companies, and circularity, and sustainable product innovation are essential for the other three with a dominant downstream footprint. However, emissions performance and ambition do not currently match these relations.
Notably, only three companies[7] have achieved material emissions reductions in recent years while others are on track to increase emissions by 2030 in line with business-as-usual trends.
Crucially, long-term targets remain insufficient. Despite the dominance of Scope 3 emissions, only one firm[8] has set an absolute, quantified target covering its full value chain; two[9] include partial upstream Scope 3 targets; and the rest either lack Scope 3 targets altogether or offer only vague references. Without full value chain targets, including absolute Scope 3 mitigation ambitions, chemical company transition plans to net-zero are simply not credible.
Even where supplier or customer engagement exists, disclosures are inconsistent and lack transparency on emissions coverage, investment scale, or expected mitigation timelines. This is particularly concerning given the sector’s growing reliance on emerging technologies to deliver on their decarbonisation goals. For context, when asked how these targets will be achieved, companies often cite breakthrough technologies, yet provide little concrete evidence to support their credibility. If emerging tech is the core delivery mechanism, then companies must substantiate it: outline the emissions reduction expected, current versus required capacity, investment needs, and deployment timelines. Instead, many disclosures are vague, reflecting a lack of seriousness which makes these initiatives unlikely to deliver on the chemical’s transition by 2030.
Incentive structures and misaligned associations put climate on the back burner
On the governance front, where effective structures and incentive frameworks are essential for translating climate ambition into action, only a few firms[10] have integrated climate into executive remuneration with incentives linked to climate KPIs. Others still treat climate as an auxiliary issue.
At the same time, many companies remain affiliated with industry groups that advocate against climate policies (e.g. AFPM, US Chamber of Commerce), despite internal climate commitments. Failure to address such misalignments exposes companies, and their investors, to regulatory backlash, litigation, and reputational harm.
Resilience is hard to measure given little clarity on capital allocation and physical risks
Transition will require significant capex from chemical companies and transition plans are only credible if the investment is costed and sourced properly. However, there is material variation across the companies in the amount of capital they invest to deliver their transition goals, ranging from 2% to 30%[11] of their total capex. Moreover, disclosure is often inadequate and inconsistent as few companies clearly distinguish between capex for decarbonisation and capex for “sustainable” capacity expansion. This lack of transparency is particularly concerning given that climate-aligned capex is among the least disclosed[12], yet most material, indicators of credible transition planning.
Despite near-universal acknowledgement of physical climate risks, meaningful integration into planning remains limited. Only two companies[13] provide a somewhat quantitative assessment. For the rest, disclosures lack granularity, leaving critical blind spots around asset resilience, potential supply chain disruptions, and future cost exposure under more extreme climate scenarios.
The chemical sector may be locking itself into fossil-feedstock infrastructure
With insufficient long-term emissions targets, reliance on emerging technologies, as well as a lack of alignment between governance structures, financial incentives, capex plans, and strategic decarbonisation plans, chemical companies have a high risk of failing on their commitments to transition.
As a result, the chemical sector may be signalling an implicit willingness to absorb additional fossil input, locking in emissions and infrastructure that are fundamentally misaligned with global climate goals. In other words, if chemical companies continue to expand production capacity without proportionate mitigation efforts, a more abrupt and costly transition will be required post-2030, likely triggered by stricter policy action and investors’ needs.
Oil and GasWhatever the pace of transition and alignment in the chemical industry, oil and gas is still facing a significant technological risk that petrochemicals are unlikely to mitigate. Carbon Tracker’s Petrochemical Imbalance has identified three additional challenges that oil and gas companies may face in their attempt to pivot towards what has historically been a secondary market.
Refiners have yet to prove they can increase chemical yields economically
We start with refiners, which face two distinct risks. Firstly, with electric vehicles eating into the market share of internal combustion engine powertrains, refineries will have to find ways to change up their product mix. They will need to reduce the share of gasoline extracted from the barrel and increase the yield of petrochemical feedstock – a feat that will be challenging both technologically and economically.
A typical barrel of oil yields 8-12% of petrochemical feedstocks, against 24% of gasoline, 34% of diesel, 10% of kerosene, and 16% of residual fuels and products. Increasing the proportion of chemicals extracted from a barrel of oil requires dipping deeper into that barrel and breaking down long-chain hydrocarbon molecules into short-chain molecules. The technology that does this sort of molecular breaking – called cracking – has existed for decades, but it has been optimised to convert heavy distillates (asphaltenes) into middle distillates (fuels); light distillates (petrochemicals) have always been a byproduct of the process. This technology could theoretically be tweaked, but that requires increasing the units’ temperature regime or changing the catalyst – in either case, a more energy-intensive process.
Technology is only part of the problem. Historically, the profit margins of light distillates have been negative, i.e. they were sold at lower prices than the crude from which they are extracted. As the share of profit-making fuels is set to dwindle, refineries may find themselves producing more of a product that tends to drag profit margins down. Stood side by side with identical compounds obtained from the much simpler process of natural gas liquids (NGL) fractionation,* which is a mandatory step in natural gas production, light distillates coming out of refineries look an even less attractive prospect.
Refining infrastructure’s fit for chemical purposes may depend on location
Another problem for refiners is geography. Many operators claim that they can repurpose existing refining infrastructure and supply chains to secure uptake of petrochemicals. However, the global petrochemical value chain has been shifting steadily towards China and North America, which have been building out their ethylene and propylene production capacities, away from historical centres in Europe.
While refineries with easy access to Asian and North American markets may be better positioned to create integrated petrochemical plants, geographically disadvantaged facilities may struggle to offload their products. Some players have already been met with setbacks in their downstream segments. For example, bp has had to shut down 1/3rd of the capacity at the Gelsenkirchen refinery in Germany; ExxonMobil has been divesting its assets across Europe and has shut down its chemical units at the Gravenchon facility in France; Shell has scrapped plans for a chemical complex in Iraq; and LyondellBasell has closed its chemical plants in the Netherlands.
Problems downstream may translate into demand substitution risks upstream
Any setbacks in the downstream segments of the oil and gas industry are bound to reverberate all the way up the value chain and impact upstream producers. If transport electrification and renewable deployment continue at pace, translating into a faster transition than currently expected, upstream producers will face a significant demand substitution risk. Oil producers will be particularly exposed, facing competition from NGLs. However, gas suppliers themselves are not immune, as renewable deployment continues at record pace.
ConclusionPut together, Carbon Tracker’s Petrochemical Imbalance and Planet Tracker’s Lessons in Chemistry highlight the tension between an oil and gas sector seeking to offload more fossil fuels into the petrochemical value chain, even as the chemical sector has pledged to reduce the use of petrochemicals in order to meet its transition commitments.
These two goals are mutually exclusive, and investors should be interrogating the risks presented by that inconsistency. Even though chemical companies are not yet doing enough to fully align with their commitments, the silver lining for oil and gas companies will be rather dim. Demand for fossil hydrocarbons is bound to buckle under the pressure of transport electrification and renewable deployment.
Most chemical companies should raise their ambitions or risk a costly transition
Despite claiming commitment to alignment with climate goals, the chemical industry has yet to line up with the most ambitious Paris-aligned decarbonisation pathway. Given the lack of progress, comprehensive emissions targets, capital allocation, and governance strategies, the chemical companies are exposing themselves to a more abrupt and costly transition post-2030. This would be caused by stricter policy action in the form of higher carbon prices, among others, especially, if chemical companies continue to expand production capacity without proportionate mitigation efforts. Moreover, slower transition and higher temperatures will have increasingly negative effects on global GDP – as a GDP-correlated sector, transition is critical to protecting the long-term demand for chemical products.
Investors focusing on the chemical industry’s climate transition and wishing to assess the credibility of these companies’ plans to transition should ask the following questions:
- Does the company disclose its full GHG footprint and have absolute, time-bound, and science-based targets for its full Scope 1, 2 and 3 emissions?
- Is climate oversight embedded at board level and is the management materially incentivised to deliver on a net-zero strategy?
- Are investments (i.e., capex) clearly linked to emissions reduction outcomes and related risk management and mitigation?
Oil and gas companies should not rely on petrochemicals as a safe harbour from transition
Regardless of the pace of transition in the chemical industry, most oil and gas players are exposed to demand substitution risks and a pivot to petrochemicals is not a safe bet. Investing in production growth upstream risks locking in long-lead, long-cycle projects at a time when demand is set to dwindle. Meanwhile, investing in downstream assets, including chemical units, may result in lower offtake, reduced utilisation rates, and weaker margins. Financial impacts would likely include significant impairments and an early onset of decommissioning liabilities on the balance sheet.
Investors with a stake or interest in oil and gas companies should ask the following questions:
- What are the company’s assumptions for long-term petrochemical demand growth?
- What are the company’s assumptions for oil demand and commodity prices?
- What margins does the company expect to achieve from a refinery being converted into a chemical plant?
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[1] IEA, World Energy Outlook 2024, p.137. BloombergNEF, Electric Cars Have Dented Fuel Demand. By 2040, They’ll Slash It. (15 August 2023). DNV, Energy Transition Outlook 2024 (2024), pp.15,107. McKinsey & Company, Global Energy Perspective 2023: Oil outlook (2024). bp, bp Energy Outlook: 2024 edition (2024), pp.29-30.
[2] For reference these are: BASF, Bayer, Dow, Incitec Pivot, Air Liquide, LyondellBasell, SABIC, and Toray Industries.
[3] The exception being Air Liquide with 64% of its emissions coming from Scope 1 and 2 activities.
[4] Bayer, BASF, Dow, and Toray.
[5] SABIC, LyondellBasell, and Incitec Pivot.
[6] In this case Air Liquide.
[7] Incitec Pivot (–33%), BASF (–25%), and Bayer (–17%).
[8] LyondellBasell.
[9] BASF and Bayer.
[10] Examples include: Air Liquide, Incitec Pivot, and Bayer.
[11] Air Liquide commit over 30% of its capex to low-carbon projects , while Bayer allocates less than 2%. Although double digit numbers might seem impressive, most of these investments are targeting capacity building rather than mitigation. i.e., Air Liquide is retrofitting industrial assets and betting on hydrogen hubs while Dow is building new net zero capacity.
[12] See CA100+ assessments.
[13] BASF and Incitec Pivot.
* NGL fractionation involves separating out all the constituent gases, i.e. ethane, propane, butane, pentane, and hexane, based on their boiling points.
The post Chemical Mismatch: Value Chain Under Strain appeared first on Carbon Tracker Initiative.
Investor confidence is built on transparency — but are current audit practice disclosures doing enough to uphold it?
22 July | Online | 16:00 UK | 17:00 CET | 11:00 NY | 08:00 SAN FRAN
Join us for a 45-minute webinar exploring how the lack of audit practice transparency poses risks to investor trust and what can be done to address it. This is your opportunity to hear from leading voices in finance, audit, and sustainability – and to ask your own questions.
Paul Lee Barbara Davidson Tino Gonese
Redington Carbon Tracker Carbon Tracker
What to expect: Tino Gonese, Analyst in the Capital Markets Transparency Team at Carbon Tracker, will open with a short presentation highlighting key insights. He’ll then be joined by a panel of experts –Paul Lee, Head of Stewardship and Sustainable Investment Strategy (Redington), and Barbara Davidson, Head of Capital Markets Transparency Team (Carbon Tracker) – for an in-depth, open audience Q&A-led discussion.
Drawing on audit reports from over 140 carbon-exposed companies this report highlights the extent to which auditors appear to be addressing, or overlooking, the financial impacts of climate and energy transition risks.
Key themes include:
- The transparency gap
- A possible audit tenure/inconsistency relationship.
- Cross border audit practice variations.
- Practical recommendations for auditors, audit committees, and regulators.
- Investor’s role in driving improved audit transparency.
This webinar is an essential for investors, regulators, audit professionals, and anyone interested in the intersection of climate risk and financial reporting.
We look forward to seeing you on the 22nd, but in the meantime, feel free to download the report or email Tino at tgonese@carbontracker.org
For previous reports in the series please see Flying Blind: The Glaring Absence of Climate Risks in Financial Reporting (2021), Still Flying Blind: The Absence of Climate Risk in Financial Reporting (2022), Flying Blind: In a Holding Pattern (2024), and Flying Blind: Accounting and Audit Regulation (2025).
The post Investor confidence is built on transparency — but are current audit practice disclosures doing enough to uphold it? appeared first on Carbon Tracker Initiative.
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