They started out as an unexpected silver lining – clearer skies and cleaner air in cities from Los Angeles to New Delhi, and a much-acclaimed return of fish and crystal clear waters to the often murky canals of Venice, Italy. By the end of last year, these local anecdotes were real and measurable markers of the unintended climate benefits of the pandemic.
While encouraging, the environmental break is not expected to continue. There are already signs that if countries try to return to normal economic activity and all associated emissions and pollution will increase again.
And when the pandemic revealed what could be viewed as low hanging fruit in the climate struggle, it also highlighted the extent of the problem.
“If you think about the scale of the action needed – if we want to limit the warming proposed in the Paris Agreement – we would have to cut CO2 emissions by 1 or 2 billion tons every year,” said Corinne Le Quéré, a professor of climate science at the University of East Anglia in the UK “This is less than what we did during the pandemic, but it’s still a large number.”
The declines in 2020 were staggering.
One in the last month in the Nature Climate Change journal found that global carbon dioxide emissions fell 7 percent last year compared to 2019. About a year ago, a paper published in the same magazine estimated that in April 2020, at the height of pandemic lockdowns in Asia, Europe and North America, daily global carbon dioxide emissions fell 17 percent compared to 2019.
“Seven percent is actually a big drop in emissions for a year,” said Le Quéré, lead author of both studies. “In absolute numbers that is 2.6 billion tons of carbon dioxide. This has never been seen before.”
However, there are already signs that global emissions could rebound significantly. A new report from the International Energy Agency, a France-based intergovernmental agency, predicted that rising global energy demands this year could push emissions above pre-pandemic levels.
Scientists are not suggesting that the solutions to climate change are to slow the economy, cripple entire industries, and impose extreme measures that disrupt people’s lives. However, experts say that after a year of profound behavioral changes that have shown how debilitating a global crisis can be, the pandemic offers important lessons for tackling climate change.
For one thing, it has shown that countries can mobilize to tackle big problems, said Le Quéré.
“It has shown that coordinated government action can produce results quickly,” she said. “The most important thing now is that policies must be good for people, good for health, good for employment and good for the economy.”
In their most recent study, Le Quéré and her colleagues found that the biggest drop in emissions over the past year was in the transport sector. By the end of the year, emissions from land transport – including cars and trucks – had decreased by 10 percent compared to 2019 and aviation by 40 percent.
When countries reopen and life returns to normal, emissions are expected to recover. It is possible, however, that at least some lifestyle changes will persist, said Zeke Hausfather, director of climate and energy at the Breakthrough Institute in Oakland, Calif.
“We’re not going to stop traveling anytime soon, but I think we’ve learned that traveling a lot isn’t essential,” he said. “Instead of flying across the country for a day to attend a conference, we can participate virtually. Telepresence, remote working and a host of other things from last year won’t just go away.”
The adjustments could have a significant impact. Transportation accounts for almost a quarter of global carbon dioxide emissions. according to the International Energy Agency. In the United States, transportation accounted for the largest share of the country’s greenhouse gas emissions in 2019, at 29 percent.
Globally, aviation only accounts for about 2.4 percent of carbon dioxide emissions, but emissions from commercial aviation rose before the pandemic. For example, from 2013 to 2018 Emissions from commercial flight operations rose by 32 percent.
Changing the way people get around might not solve climate change on its own, but it can certainly help work around the emissions equation, Hausfather said.
“We’re slowly moving in the right direction and making some of the worst outcomes less likely,” he said.
It is possible, however, to look at the climate benefits of the pandemic through a more pessimistic perspective. While a 7 percent drop in emissions in a year is significant in absolute terms, it was only attributed to the planet’s 2011 emissions levels, Hausfather said.
And the long-term effects of climate change are not due to year-to-year fluctuations, he said.
“The global warming problem is one of cumulative emissions, not annual emissions,” said Hausfather. “It’s not 2020 emissions that determine global temperatures this year or last, but all of our emissions since the industrial revolution.”
John Reilly, co-director emeritus of MIT’s Joint Science and Policy of Global Change Program, said the pandemic has also shown how difficult it can be to rely on behavior change as a solution.
“It was very difficult to get people to mask and distance themselves socially,” said Reilly. “People don’t really want to change their lifestyle or disrupt their lives. If we have to do this with behavior changes, it becomes very difficult.”
But Reilly is confident that the Covid-19 crisis has made the climate fight urgent.
“I think some people saw the pandemic and said, ‘Well, that wasn’t caused by climate change, but this is the kind of global catastrophe that could hit us with climate change. Maybe we should do something about it.’ ” he said.
There is some evidence that governments are also connecting the same dots.
President Joe Biden is hosting a virtual climate summit with other world leaders this week to reaffirm America’s commitment to fighting climate change, days after the US and China made a commitment to work together to tackle climate change. The countries published a joint statement on Sunday in which they agreed “to tackle the climate crisis, which must be addressed with the seriousness and urgency it demands”.
Other countries have also signaled their willingness to take aggressive action to combat global warming. Legislators in the European Union have signed an agreement that aims to achieve net zero emissions by 2050.
They are the kind of pledges experts will be looking for this year, especially as countries prepare to meet in November to set more ambitious emissions targets under the Paris Agreement. Biden rejoined the landmark climate agreement on the first day of his presidency, and all eyes will be on the US to demonstrate its commitment on the world stage.
“We definitely have a lot of lost ground to make up for, especially in terms of our credibility,” said Hausfather.
Le Quéré said it was difficult to overestimate the importance of climate action as countries recover from the pandemic and rebuild their economies. And perhaps the most difficult lesson of the past year was how connected the world is and how devastating a global crisis can be, spreading across borders and across all parts of society, often deepening existing inequalities.
“These are all systemic threats to global society,” said Le Quéré. “There are many parallels that are very real. The signal should now be given to governments that you cannot ignore climate change. And if you ignore it, you do so at your own risk.”