Global CO2 emissions declined by 5.8% in 2020, or almost 2 Gt CO2 – the largest ever decline and almost five times greater than the 2009 decline that followed the global financial crisis. CO2 emissions fell further than energy demand in 2020 owing to the pandemic hitting demand for oil and coal harder than other energy sources while renewables increased. Despite the decline in 2020, global energy-related CO2 emissions remained at 31.5 Gt, which contributed to CO2 reaching its highest ever average annual concentration in the atmosphere of 412.5 parts per million in 2020 – around 50% higher than when the industrial revolution began.

In 2021 global energy-related CO2 emissions are projected to rebound and grow by 4.8% as demand for coal, oil and gas rebounds with the economy. The increase of over 1 500 Mt CO2 would be the largest single increase since the carbon-intensive economic recovery from the global financial crisis more than a decade ago, it leaves global emissions in 2021 around 400 Mt CO2, or 1.2%, below the 2019 peak.

Despite global economic activity rising above 2019 levels in 2021 and global energy demand rebounding above 2019 levels, we do not anticipate a full return of CO2 emissions to pre-crisis levels. Even with an increase in CO2 emissions from oil of over650 Mt CO2 in 2021, oil-related emissions are expected to recover only around half of the 2020 drop and thus should remain 500 Mt CO2 below 2019 levels. The likely partial recovery is entirely due to the continued impacts of the Covid‑19 pandemic and related restrictions on transport activity in 2021. CO2 emissions from international aviation are set to remain 200 Mt CO2 (or one-third) below pre-pandemic levels in 2021, while emissions from road transport and domestic aviation are on track to be close to 350 Mt CO2 (or 5%) below 2019 levels in 2021. A full recovery of global transport activity would push oil-related emissions above 2019 levels and increase global CO2 emissions by over 1.5%, well above 2019 levels.

Global coal use is anticipated to rebound in 2021 and drive an increase in global CO2 emissions of around 640 Mt CO2. This would push emissions from coal to 14.8 Gt CO2: 0.4% above 2019 levels and only 350 Mt CO2 short of the global high in coal-related CO2 emissions of 2014. The power sector accounted for less than 50% of the drop in coal-related emissions in 2020, but it accounts for 80% of the rebound, largely due to rapidly increasing coal-fired generation in Asia.

CO2 emissions from natural gas combustion are expected to increase by more than 215 Mt CO2 in 2021 to reach an all-time high of 7.35 Gt CO2, 22% of global CO2 emissions. Gas use in buildings and industry accounts for much of the trend, with demand in public and commercial buildings seeing the greatest drop in demand in 2020 but the biggest anticipated recovery in 2021. 

Emerging markets and developing economies now account for more than two-thirds of global CO2 emissions, while emissions in advanced economies are in a structural decline, despite an anticipated 4% rebound in 2021.

China’s emissions are likely to increase by around 500 Mt CO2. With energy demand and emissions already growing in 2020, in 2021 CO2 emissions in China should be 6%, or almost 600 Mt CO2, above 2019 levels. All fossil fuels should contribute to higher CO2 emissions in China in 2021, but coal is expected to dominate, contributing 70% to the increase, predominantly due to greater coal use in the power sector. Despite China’s rapid growth in generation from renewables, output from coal-fired power plants has increased by 330 TWh, or nearly 7%, between 2019 and 2021.

Economic recovery in India in 2021 is set to push emissions almost 200 Mt higher than 2020, leaving emissions 1.4% (or 30 Mt) above 2019 levels. A rebound in coal demand above 2019 levels drove the emissions increase in India, with the expected rise in coal-fired electricity generation in 2021 likely to be three times greater than the increase in generation from renewables. CO2 emissions in India are now broadly on par with emissions in the European Union at 2.35 Gt, although they remain two-thirds lower on a per capita basis and 60% below the global average.

In the United States, CO2 emissions in 2021 are expected to rebound by more than 200 Mt CO2 to 4.46 Gt CO2, yet remain 5.6% below 2019 levels and 21% below 2005 levels. CO2 emissions from coal are expected to be almost 12% below 2019 as coal use for electricity generation is likely to recover only 40% of the ground lost to renewables and natural gas in 2020. Oil use, the biggest contributor to CO2 emissions in the United States, should remain almost 6% below 2019 levels as transport activity remains curtailed across 2021.

CO2 emissions are likely to rebound less in the European Union, as the economic outlook is dimmer than in other parts of the world. The expected increase of 80 Mt CO2 in 2021 will reverse only one-third of 2020’s drop. EU emissions in 2021 should stand at 2.4 Gt. Most of the 90 Mt CO2 drop in power sector emissions in 2020 will endure through 2021, with a slight anticipated increase in coal and gas-fired generation in 2021 reversing only 10% of the 2020 drop. The share of coal in electricity generation in the European Union has declined almost three-percentage points from 2019 to 2021, to less than 14%.

CO2 emissions from advanced economies have fallen by 1.8 Gt CO2 since 2000, and their share in global emissions has declined by twenty percentage points to less than one-third of the global total.