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Carbon emissions may have peaked in 2019 — but scientists aren't celebrating just yet

Reaching the peak of human-produced greenhouse gases would signal a historic turning point, but Earth is still projected to get warmer without a more drastic reduction.
A commuter walks through thick smog in New Delhi on Nov. 14, 2019.
A commuter walks through thick smog in New Delhi on Nov. 14, 2019.Manish Swarup / AP file

The coronavirus pandemic has climate scientists asking a surprising question: Will humans ever emit more greenhouse gases into the atmosphere than they did last year?

Emissions of the climate-heating gases have been on the rise since the Industrial Revolution. But even before the onset of the pandemic, those numbers had started to flatten as coal plants shuttered and were replaced with renewable sources of energy such as wind and solar power.

Now with the pandemic upending the global economy, climate scientists say 2019 might be when the peak of emissions occurred, years before experts expected them to.

“It may well be that, because of this big economic shock we're having, 2019 will be the year of peak emissions,” said Zeke Hausfather, the director of climate and energy at the Breakthrough Institute, a research organization that promotes technological solutions to environmental and development challenges.

“It's by no means guaranteed,” he added. “I'd probably give it, maybe, 50-50 odds.”

To climate experts, the pandemic is a lesson in just how difficult it will be to meaningfully reduce emissions. And experts agree that no one’s saying a global catastrophe is the way to go in order to reduce emissions.

“The world that we've been talking about moving toward is not one of broad economic ruin, displacement and crippling inequality,” said Kim Cobb, a climate scientist and the director of Georgia Tech’s Global Change Program. “Quite the opposite in fact: the pandemic doesn't get us off the hook for doing the work to create a more just and sustainable low carbon future.”

Reaching the peak of human-produced greenhouse gases would signal a historic turning point, the beginning of what would need to be a long and deep reduction in emissions if the world is to avoid the worst effects of climate change. But, experts warn, the milestone might not mean much without a steep decline in carbon emissions on the other side of the peak.

Greenhouse gas emissions rise and fall with economic activity; during recessions, emissions tend to fall. And the world is looking at a potentially deep and painful recession because of the pandemic.

In order for emissions to have peaked, Hausfather stressed, the highest-emitting countries would need to continue replacing polluting sources of energy with green energy at the rate they had been before the pandemic.

But even if emissions peaked last year, people will still have to reckon with a much hotter future unless deep cuts are made to global emissions over the following decades.

“The peak itself doesn’t mean much unless there’s a steep decline on the other side,” said Narayan Subramanian, a fellow with the left-leaning think tank Data for Progress who focuses on climate policy. “It doesn’t mean much if we hit a plateau that’s right below the peak but we still have a carbon-intensive energy system that we haven’t moved away from.”

“My worry is that celebrating hitting peak emissions will lull us into complacency and send the wrong signal about what we still need to do,” he added.

The pandemic won’t solve the climate crisis

Even with the world staying home, emissions over the course of all of 2020 are expected to only dip between 4 percent and 7 percent — which isn’t nearly enough to curb climate change.

“We actually need to reduce carbon emissions by about 8 percent every single year in order to limit warming to 1.5 degrees Celsius,” said Leah Stokes, an assistant professor at the University of California, Santa Barbara who studies climate policy. If humans managed to only heat the planet by 1.5 degrees Celsius, we might avoid some of the really catastrophic effects of climate change.

Stokes doesn’t think that emissions peaked in 2019.

“The changes that have been made are not policy changes, they are short-term individual choices, like not driving to work or flying,” Stokes said. “We need the government to do things like require the use of clean energy. Without those measures in place, I am very skeptical that we won’t see emissions rebound.”

Hopeful signs

Even before the pandemic, there had been signs that the United States was making meaningful strides toward reducing its total greenhouse gas emissions. Renewable energy sources produced more power in the U.S. than coal in 2019 for the first time in over a century. While global emissions were still on the rise, they weren’t skyrocketing as they had been in the early 2000s.

As COVID-19 wreaked havoc on the global economy, emissions plummeted. In April, when nearly every state in the U.S. was under some form of lockdown order, daily emissions plunged by about 17 percent worldwide, according to research published in the journal Nature — the largest dip in history.

An emissions rebound

There are also signs that modern life in the coronavirus era could push people away from greener transportation options.

As people begin heading back to work, they’re avoiding crowded public transportation and driving instead. Manufacturing is ramping back up, and air travel is up 400 percent from its record low point during the height of the first wave of the pandemic.

Emissions, too, are rebounding — fast. Emissions are still down from 2019 levels, but only by 5 percent rather than by 17 percent, as they were just two months ago when lockdowns and stay-at-home orders were getting imposed, according to new data published this week. Some experts warn that without policy changes in place to keep emissions down as the global economy recovers, Earth could soon see emissions above pre-pandemic levels.

“We expected emissions to come back, but that they have done so rapidly is the biggest surprise,” Corinne Le Quéré, the lead author of the study and a professor of climate change at the University of East Anglia, told The Guardian.

The economic toll of the pandemic has hit the renewable energy sector as well, which could disrupt the pre-pandemic trend of moving the energy sector away from coal toward wind and solar. More than 600,000 workers in clean energy have lost their jobs, according to a study published last month —17 percent of the total workforce in the industry.

Meanwhile, the Trump administration has poured stimulus cash into flagging fossil fuel companies. At least $113 million in taxpayer-backed loans have gone to the fossil fuel industry, an analysis by The Guardian found.

“It has already been a squandered opportunity,” Stokes said of the stimulus. “A lot of money has gone towards the fossil fuel industry. That is wasted money, and this is definitely a wasted crisis.”

The federal government has also said it would not enforce environmental regulations, and, citing the pandemic, has moved to roll back regulations on the construction of energy projects, and clean air standards.

Experts emphasized that how the country moves forward with its recovery from the pandemic will determine whether emissions have, in fact, peaked.

“The recovery from COVID-19 could potentially play a big role in our path going forward,” Hausfather said. “The world is at an inflection point.”