Global energy-related carbon dioxide emissions rose by 6% in 2021 to 36.3 billion tons, their highest ever level, as the world economy rebounded strongly from the COVID-19 crisis and relied heavily on coal to power that growth, according to new IEA analysis.
The increase in global CO2 emissions of over 2 billion tons was the largest in history in absolute terms, more than offsetting the previous year’s pandemic-induced decline, the IEA analysis shows. The recovery of energy demand in 2021 was compounded by adverse weather and energy market conditions—notably the spikes in natural gas prices—which led to more coal being burned despite renewable power generation registering its largest ever growth.
Combined with the methane emissions estimates that the IEA published last month and estimates of nitrous oxide and flaring-related CO2 emissions, the new analysis shows that overall greenhouse gas emissions from energy rose to their highest ever level in 2021.
Coal accounted for over 40% of the overall growth in global CO2 emissions in 2021, reaching an all-time high of 15.3 billion tons. CO2 emissions from natural gas rebounded well above their 2019 levels to 7.5 billion tons. At 10.7 billion tons, CO2 emissions from oil remained significantly below pre-pandemic levels because of the limited recovery in global transport activity in 2021, mainly in the aviation sector.
The rebound of global CO2 emissions above pre-pandemic levels has largely been driven by China, where they increased by 750 million tons between 2019 and 2021. China was the only major economy to experience economic growth in both 2020 and 2021. The emissions increases in those two years in China more than offset the aggregate decline in the rest of the world over the same period. In 2021 alone, China’s CO2 emissions rose above 11.9 billion tons, accounting for 33% of the global total.
China’s rise in emissions resulted largely from a sharp increase in electricity demand that leaned heavily on coal power. With rapid GDP growth and additional electrification of energy services, electricity demand in China grew by 10% in 2021, faster than economic growth at 8.4%. This increase in demand of almost 700 TWh was the largest ever experienced in China. With demand growth outstripping the increase in supply from low emissions sources, coal was used to meet more than half of the rise in electricity demand. This was despite the country also seeing its largest ever increase in renewable power output in 2021.
CO2 emissions in India rebounded strongly in 2021 to rise above 2019 levels, driven by growth in coal use for electricity generation. Coal-fired generation reached an all-time high in India, jumping 13% above its 2020 level. This was partly because the growth of renewables slowed to one-third of the average rate seen over the previous five years.