Global energy-related emissions rose by 6 per cent (over 2 billion tonnes), reaching 36.3 billion tonnes in 2021 after the economy rebounded from the COVID-19 crisis and started to rely heavily on coal to power the growth.
According to the latest analysis of the International Energy Agency (IEA), the recovery of energy demand in 2021 was compounded by adverse weather and the spikes in natural gas prices which led to more coal being burned despite the increase in renewable power generation.
“The numbers make clear that the global economic recovery from the Covid-19 crisis has not been the sustainable recovery […]. The world must now ensure that the global rebound in emissions in 2021 was a one-off – and that an accelerated energy transition contributes to global energy security and lower energy prices for consumers”, reads the IEA statement.
While coal accounted for over 40 per cent of the overall growth in global CO2 emissions, renewable energy sources and nuclear power provided a higher share of global electricity generation than coal in 2021.
Renewables-based generation reached an all-time high, exceeding 8 000 terawatt-hours (TWh) in 2021, a record 500 TWh above its 2020 level. More specifically, output from wind and solar PV increased by 270 TWh and 170 TWh, respectively, while hydro generation declined due to the impacts of drought.
The use of coal for electricity generation in 2021 was intensified by record-high natural gas prices. The costs of operating existing coal power plants across many European power systems were considerably lower than those of gas power plants for the majority of 2021.
Thus gas-to-coal switching pushed up global CO2 emissions from electricity generation by well over 100 million tonnes, notably in the United States and Europe where competition between gas and coal power plants is tightest.
The rebound of global CO2 emissions above pre-pandemic levels has largely been driven by China where they increased by 750 million tonnes between 2019 and 2021.