Global carbon dioxide emissions are predicted to decline as much as 7% in 2020 in response to reduced travel and industrial activity due to COVID-19 and other factors, according to data that the Future Earth's Global Carbon Project published ahead of the Dec. 12 five-year anniversary of the signing of the Paris Agreement on climate change.

Another report released on Dec. 9 by the United Nations Environment Programme made a similar finding but noted that a 7% decrease for 2020 would amount to only a 0.01 degree C reduction of global warming by 2050 and that countries around the world still need to step up their decarbonization pledges. Experts have forecast that emissions will climb again in 2021 once the impact of the COVID-19 pandemic on daily activities is reduced.

The Global Carbon Project report indicated that a 7% decline equivalent to a reduction of about 2.4 billion tonnes of emissions would be far greater than previously recorded for one year — 0.5 billion tonnes in 1981 and 2009, 0.7 billion tonnes in 1992 and 0.9 billion tonnes in 1945. The report said the biggest decline in emissions has been in the transportation sector.

Total global emissions are expected to be about 39 billion tonnes in 2020 with the biggest decline in emissions from the transportation sector, said the Global Carbon Project report.

Scientists have said that to limit global warming to 1.5 degrees C relative to preindustrial levels, global annual emissions would need to fall by about 7.6% each year until 2030.

The fact that COVID-19 is likely to only reduce emissions by 7% "shows that social responses alone will not drive the sustained reductions needed to effectively combat climate change," Josh Tewksbury, interim executive director at Future Earth, said in a news release.