To limit global warming to 1.5°C, carbon dioxide emissions need to be falling fast. Instead, CO2 from the burning of fossil fuels will rise by 1 per cent this year to the highest level ever, according to the Global Carbon Project.
“There is clearly no sign of the kind of decrease that is needed to limit climate change close to 1.5°C levels,” says Corinne Le Quéré at the University of East Anglia in the UK, one of more than 100 researchers around the world monitoring carbon emissions as part of the Global Carbon Project. Its latest findings were released to coincide with the COP27 climate meeting in Egypt.
There has been some progress. During the 2000s, fossil fuel emissions rose by more than 3 per cent a year on average, but during the past decade the average growth rate has fallen to 0.5 per cent.
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“Climate policy does work,” says Le Quéré. “Climate policy has played a really important role in bending this curve in emissions.”
Total CO2 emissions – including sources such as deforestation, forest fires and the regrowth of forests, as well as burning fossil fuels – have remained flat since 2015. Total human-related CO2 emissions in 2022 are projected to be 40.6 gigatonnes, slightly above 2021 levels, but below the 2019 peak of 40.9 Gt.
If this rate of emissions continues, the remaining carbon budget for having a 50 per cent chance of remaining below 1.5°C will run out in 2031, the budget for 1.7°C will run out in 2040 and for 2°C in 2052. Average global temperatures will pass these levels roughly around the time the budget runs out, give or take a few years.
However, in theory, the goal of limiting warming to 1.5°C by 2100 could still be met by reducing atmospheric CO2 levels enough for average global temperatures to fall later in the century.
In terms of fossil fuel emissions, the past few years have been unusual, making it hard to project how emissions will change in the future. “The situation is turbulent and unstable, with ups and downs in regions that are completely at odds with the longer-term trends,” says Le Quéré.
In 2020, fossil fuel emissions fell by more than 5 per cent as a result of the covid-19 pandemic, but they rebounded to nearly the previous level in 2021. Part of the 1 per cent rise this year is due to the continuing recovery of aviation, says team member Glen Peters at the CICERO Center for International Climate Research in Oslo, Norway. This is driving up oil emissions, but these aren’t as high as they were pre-pandemic.
The energy crisis prompted by Russia’s invasion of Ukraine and subsequent reduction in its gas supply to Europe has had complex effects. Gas emissions will fall slightly, by 0.2 per cent. If Russia hadn’t invaded Ukraine, gas emissions would probably have risen by 2 per cent instead, says Peters.
Instead, coal emissions are expected to rise by 1 per cent as a result of increases in India and the European Union, and might hit a new all-time peak. This is happening even though China’s coal emissions haven’t risen, unusually, with its economy hit by covid-19 restrictions.
So while emissions aren’t rising as fast as they were, it remains unclear when they will peak and finally begin to fall. “You could say there’s a positive side, but we are still very far from where we need to go,” says Peters.
Earth System Science Data DOI: 10.5194/essd-14-4811-2022
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