• "This is a dire warning that the economic recovery from the Covid crisis is currently anything but sustainable for our climate," Fatih Birol, executive director of the IEA, said in the report.
• The report comes at a time when policymakers are under intensifying pressure to deliver on promises made as part of the Paris Agreement.
• President Joe Biden will hold a virtual summit to discuss the climate emergency with dozens of world leaders this week, with global talks due to be held in Glasgow, Scotland in early November.

LONDON — Energy-related carbon emissions are on track to surge by nearly 5% this year, according to the International Energy Agency, reversing most of last year's decline caused by the coronavirus pandemic.

In the IEA's Global Energy Review 2021, published Tuesday, the group said global energy-related CO2 emissions were on course to rise to 33 billion metric tons this year, up 1.5 billion metric tons from 2020 levels.

It would reflect the single largest increase in emissions since 2010 and the second-largest increase in history.

"This is a dire warning that the economic recovery from the Covid crisis is currently anything but sustainable for our climate," Fatih Birol, executive director of the IEA, said in the report.

"Unless governments around the world move rapidly to start cutting emissions, we are likely to face an even worse situation in 2022," he added.

The report comes at a time when policymakers are under intensifying pressure to deliver on promises made as part of the Paris Agreement.

President Joe Biden will hold a virtual summit to discuss the climate emergency with dozens of world leaders this week, with global talks due to be held in Glasgow, Scotland in early November.

Yet, even as politicians and business leaders publicly acknowledge the necessity of transitioning to a low-carbon society, hopes of limiting global warming — and meeting a crucial global target — are quickly deteriorating.

Almost 200 countries ratified the Paris climate accord at COP21 in 2015, agreeing to limit the increase in the planet's average temperature to "well below" 2 degrees Celsius above pre-industrial levels and to pursue efforts to cap the temperature rise at 1.5 degrees Celsius.

It remains a key focus ahead of COP26, although some climate scientists now believe that achieving the 1.5 degrees Celsius target is already "virtually impossible." 

'A growing gap'

"During the Covid crisis, many people thought human beings would be much more environmentally directed, governments are making one pledge after another, and as a result we would have a cleaner energy system. But the numbers show a completely different picture," Birol told CNBC's "Street Signs Europe."

"There is a growing gap between what the governments say, what we read in the papers and so on, and what is happening in real life."

Birol said policymakers must make clear commitments on how they plan to substantially reduce emissions at the Leaders Summit on Climate on Thursday and Friday.

He warned that while the IEA's 2021 emissions forecast was "disappointing," the absence of immediate action would mean next year's outlook is likely to be "even worse."

The IEA said this year's rise in carbon emissions would likely be driven by a resurgence in coal use in the power sector, with more than 80% of the projected growth set to come from Asia, led by China.

Coal use in the U.S. and European Union is also expected to rise in 2021, the IEA said, but will remain "well below" pre-crisis levels.