Global CO2 emissions from energy are seen rising nearly 5% this year, suggesting the economic rebound from Covid-19 could be "anything but sustainable" for the climate, the International Energy Agency said on Tuesday.
The IEA's Global Energy Review 2021 predicted carbon dioxide emissions would rise to 33 billion tonnes this year, up 1.5 billion tonnes from 2020 levels in the largest single increase in more than a decade.
"This is a dire warning that the economic recovery from the Covid crisis is currently anything but sustainable for our climate," IEA Executive Director Fatih Birol said.
This year's rise will likely be driven by a resurgence in coal use in the power sector, Birol added, which the report forecast to be particularly strong in Asia.
It should also put pressure on governments to act on climate change. US President Joe Biden will hold a virtual summit for dozens of world leaders this week to discuss the issue ahead of global talks in Scotland later this year.
Last year, when power use dropped due to the Covid-19 pandemic, energy-related CO2 emissions fell by 5.8% to 31.5 billion tonnes, after peaking in 2019 at 33.4 billion tonnes.
The IEA's annual review analysed the latest national data from around the world, economic growth trends and new energy projects that are set to come online.
Global energy demand is set to increase by 4.6% in 2021, led by developing economies, pushing it above 2019 levels, the report said.
Demand for all fossil fuels is on course to grow in 2021, with both coal and gas set to rise above 2019 levels.
The expected rise in coal use dwarves that of renewables by almost 60%, despite accelerating demand for solar, wind and hydro power. More than 80% of the projected growth in coal demand in 2021 is set to come from Asia, led by China.
Coal use in the United States and the European Union is also on course to increase but will remain well below pre-crisis levels, the IEA said.