Energy agency report details narrow path to global net-zero emissions by 2050

The world has all the technologies it needs to begin transitioning to a net-zero-carbon energy system by 2050, says a report released 18 May by the International Energy Agency (IEA), a 30-nation organization that recommends policies to increase the reliability, affordability, and sustainability of energy. Yet meeting the deadline endorsed by President Biden and other world leaders also requires the widespread deployment of clean-energy technologies that are not yet commercially available. Most scientists agree the world must achieve net-zero emissions by midcentury to hold global temperatures to below 2 °C above preindustrial levels and avoid catastrophic climate change.

In a second report , released 5 May, the IEA warns that decarbonizing economies in that time frame will require increasing the production of certain critical minerals well beyond the scale of projects that are currently in development or being planned. More than 40 times the current world demand for lithium and 20–25 times as much graphite, nickel, and cobalt will be needed to manufacture the numbers of electric vehicle (EV) batteries, wind turbine generators, and other clean-energy systems required for a net-zero-carbon scenario. Demand for certain rare-earth elements will jump seven times from current levels. Copper consumption will more than double by 2040 due to the massive expansion of the electricity infrastructure needed as the economy moves away from fossil fuels. Nickel, zirconium, and platinum group metals will ramp up along with expansion of hydrogen production and fuel cells.

“Today, the data show a looming mismatch between the world’s strengthened climate ambitions and the availability of critical minerals that are essential to realizing those ambitions,” said Fatih Birol, IEA executive director, in a 5 May statement. Current supply and investment plans are geared toward a world of gradual, insufficient climate change mitigation measures, he added. Actions by policymakers will be needed to send a clear message of governments’ commitment to the clean-energy transition and to encourage companies to make more aggressive investment decisions.

The agency’s 2050 pathway to net-zero carbon calls for EVs to account for 60% of global car sales by 2030, compared with 2.6% in 2019, and a ban on sales of new fossil-fuel cars beginning in 2035. Other near-term goals include requiring all new buildings to be emissions-free by 2030, ramping up production of low-carbon hydrogen to 150 million tons by that year, and capturing 4 gigatons of carbon dioxide from the atmosphere by 2035.

For the next decade, the agency says, widespread deployments of existing technologies can provide the first stage of emissions reductions needed to meet the 2050 goal. But beyond 2030, about half of the remaining carbon reductions will depend on technologies that are now in the demonstration or prototype stages. Advanced batteries, electrolyzers for hydrogen production, and direct-air carbon dioxide capture systems will be especially critical in the 2030–2050 period, the IEA says. The agency argues that around $90 billion in funding globally—$65 billion more than is currently budgeted—is urgently needed to complete a portfolio of clean-energy demonstration projects before 2030.

That emerging technology will require mineral components. A typical electric car requires six times the mineral inputs of a conventional car, and an offshore wind plant requires 13 times the mineral resources of a natural gas–fired power plant. The IEA estimates that by 2030, the expected supply from existing mines and projects currently under construction will meet only half of projected lithium and cobalt demand and 80% of copper needs.

The IEA-forecasted supply levels for energy-critical minerals far surpass those contained in a 2020 World Bank report, which said that holding global temperature increases to below 2 °C by 2050 would require graphite, lithium, and cobalt production to increase by more than 450% from their 2018 levels. That report also stressed uncertainties, particularly in forecasting demand for the elements used in batteries. The outcome of R&D underway on a number of alternative energy-storage technologies, together with market forces and policy choices, will determine actual post-2030 demand levels for lithium, cobalt, and graphite, it said.

Thomas Graedel, a Yale University chemical engineer, says both the IEA and the World Bank failed to consider additional demand, unrelated to clean energy, for some of those materials. He notes, for instance, that chemicals for desulfurizing fossil fuels, ceramics, and superalloys used in aircraft engines account for about half of US cobalt consumption today. And that demand for cobalt in aircraft could ramp up: Replacing nickel with cobalt as the primary element in superalloys used for jet turbine blades has been proposed to improve engine efficiency, he says.

Technological changes and material substitutions could significantly reduce demand for some critical minerals, the IEA notes in its minerals report. For example, the amount of cobalt in EV lithium-ion battery cathodes has been engineered downward in newer designs. The first EV nickel-manganese-cobalt cathodes contained equal parts of each metal, says George Crabtree, director of the Joint Center for Energy Storage Research at Argonne National Laboratory. Now the most common ratio is 6-2-2, respectively. The lithium iron phosphate batteries that have gained ground in EVs, particularly in China, are cobalt-free. (See Physics Today, May 2021, page 20 .) Similarly, at least one US company is developing permanent magnets that don’t require the rare-earth metals neodymium, dysprosium, and terbium, which are alloyed into the permanent magnets that are vital for today’s EVs and for direct-drive wind turbines (see Physics Today, February 2021, page 20 ).

The 5 May report says that by 2040, recycled lithium, cobalt, nickel, and copper could reduce by around 10% the combined primary supply requirement of those metals. Graedel says the extent of recycling will depend on whether designers begin to build end-of-life considerations into new products.

New mining developments face a host of challenges, including price and market volatility, lengthy timelines, growing scrutiny of environmental and social impact, declining resource quality, and higher exposure to climate stress, such as water shortages, the energy agency says. The report recommends that governments spell out their long-term commitments for emission reductions, promote technological advances, scale up recycling, maintain high environmental and social standards, and strengthen international collaboration between producers and consumers of the minerals.