By Katherine Wilkin - Public Employees for Environmental Responsibility, June 8, 2021
As the push for renewable energy sources continues as a means to combat climate change, the demand for metals and minerals that make up critical components of clean energy technology will be on the rise. While some of these minerals can be obtained via deep-sea mining, the environmental impacts of such efforts are not well understood. In moving to a clean energy economy, governments and international non-governmental organizations need to research, understand, and mitigate the negative impacts to the environment and communities that can and will result from activities like deep-sea mining before allowing projects to go forward.
The United States Geological Survey has identified 11 metals and minerals as critical commodities in renewable energy technologies: arsenic, gallium, germanium, indium, tellurium, aluminum, cobalt, graphite, lithium, manganese, and rare earth elements. Silver, copper, selenium, silica, nickel, and cadmium are also used in solar panels, wind turbines, and batteries. Several of these critical metals and elements can be obtained via deep-sea mining from three different types of deposits: (i) cobalt-rich crust that contains manganese, iron, cobalt, copper, nickel and platinum; (ii) polymetallic nodules which are rich in manganese, nickel, copper, cobalt, molybdenum and rare earth elements; and (iii) sea-floor massive sulphides which contain copper, gold, zinc, lead, barium and silver.
Whether deep-sea mining is necessary to acquire enough minerals to fuel the renewable energy shift remains an unanswered question. In a May 2021 report on the need for minerals to power energy transition technologies, the International Energy Agency predicted that by 2040, total mineral demand for clean energy will be four times current demand. Electric vehicles and battery storage technology account for about half of this predicted growth in mineral demand. The Institute for Sustainable Futures at the University of Technology Sydney indicated in 2016 that this increased demand for materials can be satisfied without utilizing deep-sea mining even under a target of 100% renewable energy use by 2050. Further, Carbon Brief reported in 2018 that reserves of lithium and cobalt are likely to be sufficient to meet demand, but there are outstanding concerns of supply chain bottleneck causing delays. This is supported by the IEA report, which indicated that problems in supply of minerals is more likely to be a matter of quality rather than quantity. However, a 2018 study supported by the Dutch Ministry of Infrastructure found that the current supply of critical metals is not enough to transition to a fully-renewable energy system in the Netherlands. Additionally, a 2019 projection of demand for cobalt, lithium, and silver looking as far as 2050 found that “reserves” of these materials—a portion of total available resources that can be extracted economically—will not be sufficient to meet demand for cobalt, and demand for lithium can only be met in a “potential recycling scenario” with improved recycling rates over what is being conducted at present.
With the growing demand for metals and materials for use in renewable energy technologies, concerns arise about the environmental impacts and environmental justice implications of mining on land. For example, cobalt mines in the Democratic Republic of Congo have been the site of human rights violations, child labor, and severe environmental pollution. For that reason, deep-sea mining of these materials may present an option with fewer direct human impacts and environmental justice concerns.