London CNN Business  — 

Global carbon dioxide emissions are set to surge dangerously this year as the global economy undergoes a huge recovery.

In a new report, the International Energy Agency estimates that carbon emissions from energy use are on track to spike by 1.5 billion tonnes in 2021, as heavy coal consumption in Asia, and in China in particular, outweighs rapid growth in renewable sources. That would be the second largest annual increase in energy-related emissions in history.

“This is a dire warning that the economic recovery from the Covid crisis is currently anything but sustainable for our climate,” Executive Director Fatih Birol said in a statement. “Unless governments around the world move rapidly to start cutting emissions, we are likely to face an even worse situation in 2022.”

The Paris-based group is sounding the alarm before 40 world leaders come together later this week for a two-day virtual summit on the climate crisis convened by President Joe Biden. Birol called it a “critical moment to commit to clear and immediate action.”

The United Kingdom will announce a steeper target for reducing carbon emissions ahead the summit, a government source confirmed to CNN Business on Tuesday. Prime Minister Boris Johnson will pledge to reduce UK emissions by 78% by 2035 compared to 1990 levels, the Financial Times reported on Monday.

As countries around the world locked down last year and people were instructed to stay at home to limit Covid-19 infections, emissions fell dramatically.

But any climate benefit from the pandemic looks poised to be short-lived. The IEA estimates that global energy demand will rise by 4.6% in 2021 and exceed 2019 levels, fed by rising energy use in developing economies and emerging markets.

Energy-related emissions are expected to end the year just below where they stood in 2019, reversing 80% of the decline seen in 2020.

A resurgence in the use of coal is of particular concern, with demand expected to approach its 2014 peak this year.

China is expected to account for 50% of global demand growth for coal. Use in the United States and Europe is also rising but is expected to stay “well below pre-crisis levels.”

Earlier this week, United Nations Secretary-General António Guterres called for developed countries to phase out the use of coal by 2030, and for an end to the construction of new coal-fired power plants.

Electricity demand, meanwhile, is projected to see its fastest growth in more than a decade.

But there’s some good news: More than half of the increase in global electricity supply will come from renewable sources in 2021, driven in part by growing solar and wind energy output from China.

The IEA’s estimates are subject to “major uncertainty” given the lack of clarity on the trajectory of Covid-19 infections and vaccinations. If travel recovers sooner than expected, for example, energy demand will increase even further.

– Luke McGee and Sarah Dean contributed to this article.