Covid-19 pandemic restrictions saw an unprecedented fall in greenhouse gas emissions in the first half of 2020 – larger than during the 2008 financial crisis and even World War II – experts said on Wednesday.
As governments ordered lockdowns to try to crush the first wave of COVID-19, CO2 emissions from transport, power and aviation plummeted, the international team of researchers said.
Using data including hourly electricity production, vehicle traffic from more than 400 cities worldwide, daily passenger flights and monthly production and consumption figures, they determined that the emissions drop was the largest in modern history.
They suggested some fundamental steps that could be taken to stabilize the global climate as countries look to recover from the economic shock of the pandemic.
They noted however that emissions had rebounded to their usual levels by July, when most nations had eased lockdown measures.
Zhu Liu from the Department of Earth System Science at Tsinghua University in Beijing said the study was the most accurate yet undertaken on the pandemic's effect on emissions.
We were able to get a much faster and more accurate overview, including timelines that show how emissions decreases have corresponded to lockdown measures in each country, said Zhu, lead author of the study published in Nature Communications.
The team found that CO2 emissions from transport decreased by 40% in the first half of 2020, and power production and industry emissions fell 22% and 17% respectively.
With more people working from home, the study showed a perhaps surprising 3 per cent fall in residential emissions – something researchers attributed to an abnormally warm winter leading to lower heating consumption.
An international plan to limit global warming outlined in the 2015 Paris climate deal aims to cap temperature rises well below 2 degrees Celsius compared with pre-industrial levels.