Coronavirus shutdowns have sent greenhouse gas emissions off a cliff. Early estimates project global emissions will decline by 5% to 8% by the end of the year—which might seem like a win for the climate. Emissions need to drop about 7.6% every year until 2030 to keep global warming in check. But as economies kick back into gear, emissions will return to where they were, or worse.
Now, the first peer-reviewed analysis of the pandemic’s impact on carbon dioxide emissions highlights another reason this kind of global crisis makes a poor model for climate action: It’s the most-polluting sector that saw the smallest percent decline in emissions.
Electric power plants are responsible for almost half of global CO2 emissions. But at the height of the coronavirus global shutdown, their emissions fell by only 7.4% compared to 2018 averages, from about 44.6 million metric tons per day to about 41.3 million.
That drop is based on modeling from climate scientists at UK’s University of East Anglia and Stanford University, who estimated in a paper published in Nature Climate Change that peak emissions reductions—when the largest share of global emissions were subject to the greatest degree of confinement—occurred around April 7.
The biggest percentage drop seen by April 7, no surprise, came from the aviation industry (it saw a 60% drop, or 1.7 million metric tons). And the biggest raw drop in emissions came from surface transportation, which fell by 36%, or 7.5 million metric tons. That figure includes personal vehicles as well as trucks and domestic and international shipping. Stay-at-home orders that kept personal vehicles off the road were likely the main driver; in the US, light-duty vehicles account for about 60% of these emissions.
But those are exactly the emissions that are likely to rebound after lockdown orders are lifted. And achieving that dramatic dip took all the individual behavior change the world could muster. It’s barely getting us where we need to be, and with a lot of pain.
These findings carry important implications for the shape of global climate action, said Leah Stokes, a political scientist with a focus on energy policy at the University of California, Santa Barbara. Specifically, they highlight that individual choices that tend to get a lot of attention as causes of climate change—how much we fly and drive—can only do so much when they aren’t accompanied by policy changes to decarbonize the electric grid.
“This really shows the potential limits that extreme measures can deliver with the current energy mix,” Stokes said. “This is the upper bound of what we can achieve with changes to individual behavior.”
It also serves to remind us how the responsibility to decrease emissions is unequally distributed around the globe. Drawing on a wide range of economic indicators, including road and air traffic, manufacturing data, and electricity consumption, the researchers found that global emissions on April 7 bottomed out about 17% lower than the 2018 daily average. But that maximum drop varied widely region by region.
The regional maximum emissions drops demonstrate there’s only so much a low-emitting country can do to improve the global situation. The highest emitters bear the greatest responsibility.