Lockdowns around the world cause sharpest drop in carbon emissions since records began.
Carbon dioxide levels have plummeted since lockdowns were imposed around the world due to the coronavirus crisis, research has shown.
The study published in the journal Nature Climate Change shows that daily emissions dropped by 17 percent, or 17 million tonnes of carbon dioxide, by early April compared with 2019 figures.
The research, which is the first definitive study of global carbon output this year, said that these levels have not been seen since 2006. This comes as large sections of the global economy are brought to a near standstill due to the coronavirus pandemic.
Aviation, the economic sector most impacted by lockdowns, only accounts for 10 percent of the decrease in emissions during the pandemic. Emissions from surface transport, such as cars, account for almost half (43 percent) of that decrease. Emissions from industry and power sectors together account for a further 43 percent of the decrease.
The analysis shows that social response alone (working from home, driving less and not flying), without increases in wellbeing and/or supporting infrastructure, will not drive the deep and sustained reductions needed to reach net zero emissions.
"This is a really big fall, but at the same time, 83 percent of global emissions are left, which shows how difficult it is to reduce emissions with changes in behaviour," said Corinne Le Quéré, a professor of climate change at the University of East Anglia, and lead author of the study. "And it is not desirable - this is not the way to tackle climate change."
She continues by saying that, "population confinement has led to drastic changes in energy use and CO2 emissions. These extreme decreases are likely to be temporary though, as they do not reflect structural changes in the economic, transport, or energy systems."
As countries slowly get back to normal activity, over the course of the year the annual decline is likely to be roughly 7.5 percent. If pre-pandemic conditions of mobility and economic activity return by mid-June, the decline will only be 4 percent.
That would still represent the biggest annual drop in carbon emissions since the second world war, and a stark difference compared to recent trends, as emissions have been rising about 1 percent annually.
This annual drop is comparable to the amount of annual emission reductions needed year-on-year across decades to achieve the climate objectives of UN Paris Agreement. But Le Quéré says that it would make "a negligible impact on the Paris Agreement."
Emissions must fall to net zero by mid-century to meet the goals of the Paris agreement and keep climate change from reaching catastrophic levels, according to the Intergovernmental Panel on Climate Change. The fall in carbon resulting from the Covid-19 crisis reveals how far the world still has to go, said Le Quéré.
"The drop-in emissions is substantial but illustrates the challenge of reaching our Paris climate commitments. We need systemic change through green energy and electric cars, not temporary reductions from enforced behaviour." Added Professor Rob Jackson of Stanford University and Chair of the Global Carbon Project who co-authored the analysis.
"If we take this opportunity to put structural changes in place, we have now seen that it is possible to achieve."
The authors warn that the rush for economic stimulus packages must not make future emissions higher by delaying New Green Deals or weakening emissions standards.