Stay-at-home orders around the world have set the stage for an unintentional experiment: What happens to the planet when some of the most polluting activities grind to a halt?
Carbon emissions have plummeted as people stick close to home, leading to drastic declines in the use of cars and planes. Even some industries that are less consumer-focused have seen emissions fall.
And while that may seem like welcome news, many environmentalists now worry that the public will draw the wrong conclusions from what is likely to be a temporary drop in pollution. They’re concerned people will fall into one of two camps: that significant progress has been made in battling climate change, or that stopping global warming requires a massive disruption to the economy and day-to-day living.
“This drop definitely lets us know human activities are a big factor in heat trapping emissions. But that said, the lesson is not that you tank the global economy,” said Brenda Ekwurzel, a climate scientist with the Union of Concerned Scientists. “You can’t have lots and lots of lockdowns and think you’re solving the climate crisis.”
“You have to do things in a sustained way rather than in a crisis way, which is what we’re doing now with COVID-19. It’s so destructive and affects the economy,” she said.
The massive disruption to daily life amid the coronavirus is projected to lead to the largest drop in global emissions since World War II. The International Energy Agency (IEA) is predicting an “unprecedented” 8 percent drop in global carbon emissions for 2020.
The IEA found that during the first three months of 2020, global emissions were 5 percent lower than in the same period last year, largely due to decreases in emissions from coal, oil and natural gas. In the U.S., the drop was 9 percent.
But any decline is likely to be short-lived, highlighting the magnitude of the effort needed to address climate change over the long term.
“The changes we need must be year on year. An 8 percent decline in emissions would be a huge decrease,” said Rob Jackson, an environmental scientist at Stanford University and head of the Global Carbon Project.
“If next year is flat or goes back up, it's not enough to get us to our climate needs,” he said.
The 9 percent drop cited in the IEA report would put the U.S. on track to meet its Paris climate accord goals, but only if it kept that up beyond 2020.
“We’d need to do it year after year and, there’s a question of how much you can do by just stopping your car,” said Steven Davis, a professor at the University of California, Irvine.
Though transportation is one of the largest source of global greenhouse emissions, coronavirus has impacted just a portion of transit.
“If you were to cut all transportation emissions in half, you’d get a 10 percent drop in emissions,” Jackson said. “But we’re not doing that because the decline in freight and delivery are not to the same level as what we all focus on, which is our cars.”
To be sure, mainstream environmental groups aren’t supportive of cutting emissions the quarantine way, in large because it isn’t sustainable.
Instead, many experts have been calling for long-term investments in more environmentally friendly infrastructure that would boost public transit and ease the transition to electric vehicles while pushing emissions reductions in electricity and how goods are transported worldwide.
“It does need to be a similar magnitude of change,” Davis said of the resulting emissions drop under quarantine. “It just needs to be coordinated and not prevent people from going to work and living their lives.”
Ekwurzel sees that investment as a way to grow the economy, given that many sustainable energy industries require more human capital than their fossil fuel counterparts.
“Locking ourselves in our houses isn't a climate solution,” she said. “It’s structural. It's how we have invested in our energy supply around the world, and that is what has to change. We do have lots of solutions that could help with getting out of this economic crisis because the scale needs to be massive and that’s many more jobs.”
On Capitol Hill, Democrats have been pushing to include tax credits for the renewable energy industry in a variety of legislative packages, but they have failed to make it through Congress.
Davis worries that some of the broader momentum behind the climate fight might be derailed by the pandemic.
“Usually the environment is something that people prioritize when they’re kind of flush. Things are going well, so people say, ‘Why not try these new energy technologies and see if we can clean things up a bit.’ But when you’ve lost your job and can’t pay rent, you’re not prioritizing putting solar panels on your roof” he said.
That aversion to new spending can be true on both the personal and governmental level, he said.
“There’s a kind of rosy picture from some, but I think this could spell tough times for transitioning to cleaner forms of energy, particularly because oil and gas are at rock bottom prices for other reasons,” Davis said.
If there is a long-term slope in emissions, a sluggish economy may be a bigger factor than the quarantines. Past recessions have also coincided with a drop in pollution.
“The recession may have a bigger effect on climate than short-term behavior changes of sheltering at home,” Jackson said. “I hope people remember the lessons of clean air and not having to commute an hour a day and things like that, but based on past experience, emissions will go right back to normal” once the upcoming rebounds, he said.
The decline in emissions in such a short period of time has been so significant as to be visible to the naked eye, most notably in cities like Los Angeles, where a typically hazy skyline has lifted, leaving some hopeful there will be a renewed push to limit behaviors they now see can have real results.
“The natural experiment of stopping all at once is showing people — and with air quality that’s really evident — what it would be like if we didn’t have a fossil fuel-based system,” Davis said.
“The COVID outbreak is interesting because it demonstrates it is technically possible for us to close down whole sectors of our economy, but what it also showed is that doing it too rapidly and without planning for substitutes is disastrous.”
— This report was updated at 9:25 a.m.