Daily carbon dioxide emissions from energy use and heavy industry fell by 17% globally in early April, under peak coronavirus lockdown, scientists have estimated.
As governments restricted travel to curb the spread of Covid-19, emissions from aviation were slashed by up to 75% and road transport halved in some countries. Emissions related to household use rose by 5%, compared to the 2019 daily average.
The study, published in Nature Climate Change on Tuesday, forecast annual emissions falling 4-7% from 2019 to 2020, depending on how constrained people’s movement is for the rest of the year.
“Population confinement has led to drastic changes in energy use and CO2 emissions,” said Corinne Le Quéré, lead author of the study, in a press release. “These extreme decreases are likely to be temporary, however, as they do not reflect structural changes in the economic, transport, or energy systems.”
The peer-reviewed results are based on data scraped from a range of sources, such as electricity use and mobility tracking services. Official CO2 data typically take 1-2 years to compile.
The findings are broadly in line with analysis from the International Energy Agency (IEA) last month, which predicted an 8% decline in annual emissions.
Getting estimates fast can help policymakers formulate climate-friendly recovery packages as they try to restart economies after lockdown, said study co-author Glen Peters, of Cicero in Oslo.
“We can learn the size of different effects for different kinds of policy,” Peters told Climate Home News. For example, it gives an indication of the emissions savings of avoiding the commute to work.
“You would not stop people from visiting their granny” for climate purposes, he said, but “you might incentivise more people to have a home office”.
One of the biggest climate risks as restrictions are lifted is that people will turn to cars instead of public transport, to maintain physical distance from each other.
While the IEA says renewable sources have proved more resilient in the crisis than fossil fuels, the economic downturn is expected to slow investment in all forms of energy.
The drop in emissions is not as deep as you might expect given the drastic changes to people’s lives, noted Peters, showing how deeply entrenched fossil fuelled energy is in the economy. “It is a good illustration of how hard climate policy is.”