Global energy-related carbon dioxide emissions rose 6% in 2021, reaching their highest level ever due to increased use of coal power plants, according to new analysis from the International Energy Agency (IEA).
The increase in global CO2 emissions was the largest in history in absolute terms, more than offsetting 2020's pandemic-induced declines, according to the IEA. While global coronavirus lockdowns reduced emissions in 2020, the global economy recovery of 2021 brought them back up. And that recovery was fueled by coal.
Coal accounted for 40% of the overall increase in global CO2 emissions in 2021, according to the IEA. Natural-gas emissions also surged past 2019 levels, but CO2 emissions from oil remained well below pre-pandemic levels because of a slower recovery in the transportation sector, specifically aviation, the IEA said.
Coal mine [CREDIT: Global Climate Budget 2018]
The use of coal for electricity generation in 2021 was driven in part by high natural-gas prices, which led to some gas-to-coal switching, particularly in the United States and Europe where competition between the two energy sources is the tightest, according to the IEA.
However, the analysis said the increase of CO2 emissions was largely driven by China, which saw economic growth and a related spike in electricity demand from its largely coal-fired grid.
The news wasn't all bad, though. The analysis noted that renewable energy and nuclear power provided a higher share of global electricity generation than coal in 2021, reaching an all-time high.
Coal, by Flicker user oatsy40 (Used Under CC License)
Still, this is quite a turnaround from two years ago, when coal plants were being retired at a record pace. Energy from renewables was widely expected to be cheaper than that from coal—with today's dynamics certainly not part of that forecast. The Brookings Institution went so far as to map out reasons for why coal wouldn't rebound. That was 2016, and apparently things are different now.
In the U.S., a case in which coal interests challenge the EPA's ability to set power-generation emissions was recently elevated to the Supreme Court. The plaintiffs' goal is to prevent the EPA from enacting stricter emissions rules that would trigger a shift to renewable energy.
The electricity grid is a major source of greenhouse gas emissions, but making it cleaner is also relevant to electric cars. As the grid gets cleaner, the overall emissions of EVs are further reduced.