Global carbon dioxide emissions could fall by as much as seven percent this year, depending on continued restrictions and measures of social distance during the coronavirus pandemic, research published in the journal Nature Climate Change indicated on Tuesday.
The study, carried out by a group of scientists from institutions in Europe, the United States and Australia, analyzed daily CO2 emissions in 69 countries, 50 U.S. states, 30 Chinese provinces, six economic sectors and three levels of containment, using data from the daily electricity usage and mobility tracking services.
In 2019, the world emitted about 100 million tonnes of carbon dioxide a day by burning fossil fuels and cement production, according to the survey.
In early April 2020, emissions fell to 83 million tonnes per day, a drop of 17%, and emissions in some countries fell by an average of 26% during the peak of confinement.
If pre-pandemic conditions return in mid-June, emissions in 2020 could decrease by four percent compared to 2019, but if restrictions remain around the world until the end of the year, emissions could fall by seven percent , added the report.
This would be the largest single annual reduction in absolute emissions since the end of World War II.
A UN report last year said that the emissions needed to decrease 2.7% per year continue to warm well below 2 ° C and 7.6% per year to keep below 1.5 ° C.
"Population confinement has led to dramatic changes in energy use and CO2 emissions," said lead Canadian author Corinne Le Quere of the University of East Anglia.
"These extreme reductions are likely to be temporary, as they do not reflect structural changes in the economic, transportation or energy systems," he added.
China recorded the biggest drop in emissions in April, followed by the United States, Europe and India.
In countries with the strictest blocking restrictions, emissions from aviation fell by 75% in early April, while emissions from land transport fell by 50% and energy generation by 15%.
Industry emissions fell by around 35%, with a lack of data causing some uncertainty. Emissions from residential buildings, however, increased by five percent, according to the study.
"The emission reductions that occur because of COVID-19 will be clearly unprecedented. What is less certain is how the economy will recover in late 2020 and 2021," said Glen Peters at the CICERO Center for International Climate Research in Norway , who participated in the study.
"As different countries and sectors recover, it is not clear whether activity levels will return to normal levels or whether we can see permanent changes in behavior," he added.