The biggest annual fall in CO2 emissions since 1945 – around 7% – has been driven by the global response to Covid-19, says a group of eminent scientists in a report from the Global Carbon Project published in the Earth System Science Data’s journal.

While France and the UK saw the greatest falls, mainly due to severe shutdowns in response to a second wave of infections, China has seen such a large rebound from coronavirus that overall emissions are expected to grow this year.

The Global Carbon Project says that carbon emissions declined by 2.4 billion tonnes.

“Although global emissions were not as high as last year, they still amounted to about 39bn tonnes of CO2, and inevitably led to a further increase in CO2 in the atmosphere,” says lead researcher Prof Pierre Friedlingstein at the University of Exeter, UK.

“The atmospheric CO2 level, and consequently the world’s climate, will only stabilise when global CO2 emissions are near zero.”

Across Europe and the US, the drop was around 12% over the year, but some individual countries declined by more.

France saw a fall of 15% and the UK went down by 13%, according to one analysis, which is attributed to both countries having a lot of emissions from transport.

In France, 40% of emissions are from transport because so much of its electricity is generated by nuclear power stations.

Aviation around the world has been badly hit by restrictions and by the end of this year, it is expected that emissions from this sector will be 40% below 2019 levels.

One country that has bucked the trend is China. The research team expects it will see a 1.7% fall in emissions this year, but some analysis suggests that China has already rebounded enough from Covid-19 that the overall carbon output may have increased.

The data shows that China experienced a big drop in emissions in February and March.

Although current figures are still under review, they show that at the end of 2020, China is at least close to having the same level of daily emissions as in 2019. Some of estimates suggest its emissions may have actually increased for the year as a whole in 2020 relative to 2019, despite the pandemic.

The annual growth in global CO2 emissions fell from around 3% in the early years of this century to around 0.9% in the 2010s. Much of this change was down to a move away from coal as an energy source.

All the researchers involved in this project agree that a rebound of emissions in 2021 is almost certain.

To minimise the effect scientists are urging a ‘green’ rather than a ‘brown’ response, with recovery funding spent on sustainable projects, not on fossil fuels.

The scientists say that meeting the goals of the Paris Climate Agreement will need cuts of up to 2bn tonnes every year for the next decade.

To read the study visit: https://essd.copernicus.org/articles/12/3269/2020/

The Global Carbon Project is here: https://www.globalcarbonproject.org/carbonbudget/

More about the data publishing journal Earth System Science Data: https://www.earth-system-science-data.net/