Power demand is outstripping the growth of renewables, leaving coal and gas to fill the gap and threatening to drive emissions from electricity generation to record levels, warned the International Energy Agency (IEA).

After falling last year on Covid impacts global power demand will increase by almost 5% this year and 4% in 2022, predicted the Paris-based agency, with China and India the biggest drivers.

But the IEA said projected growth of renewables output – 8% in 2021 and more than 6% in 2022 – will only allow it to cover about half that extra demand.

Almost half that slack will be taken up by fossil sources, with nuclear the rest, said the body’s latest Electricity Market Report, as it warned power sector emissions are set to increase by 3.5% in 2021 and by 2.5% in 2022, reaching record highs.

“Renewable power is growing impressively in many parts of the world, but it still isn’t where it needs to be to put us on a path to reaching net-zero emissions by mid-century,” said Keisuke Sadamori, IEA director of energy markets and security.

“As the economy rebounds after the pandemic, we’ve seen a surge in electrical generation from fossil fuels. To shift to a sustainable trajectory, we need to massively step up investment in clean energy technologies – especially renewables and energy efficiency.”

The IEA has previously warned over the persistence of coal in Asian generation mixes, and said output from the dirtiest fossil source could even hit an all-time high in 2022.