WASHINGTON – America’s greenhouse gas emissions from energy and industry declined by more than 10 percent in 2020, reaching their lowest levels in at least three decades as the coronavirus pandemic criticized the brakes on the country’s economy. According to an estimate published Tuesday Made by the Rhodium Group.

However, the steep decline was the result of extraordinary conditions and experts warned that the country still faced enormous challenges in controlling pollution from global warming. In the coming years, it is widely expected that U.S. emissions will recover once the pandemic subsides and the economy returns to life – unless policymakers take stronger measures to clean up the country’s power plants, factories, cars and trucks.

„The most significant cuts in the past year have been related to transportation, which remains heavily dependent on fossil fuels,“ said Kate Larsen, a director at the Rhodium Group, a research and consulting firm. „But as vaccines become more prevalent, and depending on how quickly people feel comfortable enough to drive and fly again, we expect emissions to return unless major policy changes are implemented.“

Before the outbreak of the pandemic, America’s emissions had been slowly but surely declining since 2005, due in large part to facilities that generate electricity. It was moved away from coalDirtier fossil fuels, in favor of cheaper and cleaner natural gas, wind and solar energy. Over the past decade, utilities have shut down hundreds of coal-fired power plants despite President Trump’s efforts to revive the industry.

Then the Corona virus arrived. While the rulers put their states under closure last spring and house the Americans in their place, Emissions are starting to fall Across parts of the economy have rarely seen sustained downturns before.

Transportation, the nation’s largest source of greenhouse gases, saw a 14.7 percent reduction in emissions in 2020 as millions of people stopped driving to work and airlines canceled flights. While travel began to recover again in the latter half of the year as states relaxed lockdowns, Americans have cut 15 percent more miles compared to the entire last year than they did in 2019 and demand for jet fuel has fallen by more than a third.

Emissions from heavy industries, such as steel and cement, fell 7 percent in 2020 as auto makers and manufacturers produced fewer goods amid the economic recession. American buildings, which produce carbon dioxide when they burn oil or natural gas for heating, have seen emissions drop 6.2%, driven by both closures and warmer than average weather.

In the electricity sector, emissions decreased by 10.3 percent in 2020, driven by a sharp drop in coal burning. As the demand for electricity declined nationwide, so did the utilities She ran their coal plants a lot Because coal has become the most expensive fuel in many parts of the country. Instead, they used more natural gas – which produces less carbon dioxide from coal, but still generates large amounts of heat-trapped methane – and relied more on wind and solar energy that are zero emissions.

Renewable energy has surged in 2020, as energy companies overcome disruptions from the pandemic To build a record number of new wind turbines and solar panels Before the main deadline for claiming a federal tax credit. The United States last year produced as much electricity from renewable sources as it did from coal, a milestone that had never been reached before.

The rhodium group said the nationwide drop in emissions was the biggest drop for at least one year since World War II, and put the United States within walking distance of one of its main climate targets under the Paris Agreement, a global agreement. Nearly 200 governments tackle climate change.

As part of this agreement, former President Barack Obama pledged that US emissions would drop 17 percent from 2005 levels by 2020. President Trump disavowed the Paris Agreement, and before last year, it appeared that the United States would not achieve this goal. But in the wake of the pandemic, US industrial emissions are now 21.5 percent below 2005 levels.

But this milestone comes with many caveats. First, these numbers do not represent any increase in the emissions produced Of the forest fires recorded last year in the West, Burning millions of acres of forests and grasslands, sending carbon dioxide away in all of those trees into the atmosphere.

One preliminary estimate in November from Bloomberg He suggested wildfires could offset nearly 3 percent of the decline in US emissions from energy and industry last year. While many of the trees that caught fire will eventually grow, absorbing carbon dioxide as they do, this process will take years. Scientists have warned that wildfires will only get more widespread and more frequent as the planet warms.

Another caveat is that US emissions can return once the vaccines are widely distributed and the economy recovers. The Rhodium Group report indicated a similar recovery after the 2008-2009 financial crisis that caused emissions to drop sharply. She noted that several sectors, such as air travel and the steel industry, have already recovered in recent months.

„Unfortunately, 2020 tells little of what we can expect to see in 2021 and beyond,“ the report concluded. „The vast majority of the emission reductions for 2020 have been the result of reduced economic activity rather than any structural changes that would bring about permanent reductions in the carbon intensity of our economy.“

Scientists warn that even a major one-year drop in emissions is not enough to stop global warming. Until human emissions are essentially eliminated and nations no longer add greenhouse gases to the atmosphere, the planet will continue to warm. As if to confirm this warning, European researchers It was announced last week 2020 will very likely be related to 2016 as the hottest year on record.

President-elect Joseph R Biden Jr. has described global warming as a top priority, setting a goal of reducing America’s emissions to net zero by 2050. In doing so, experts said, It may require major new steps To accelerate the use of renewable electricity, converting Americans from gasoline-powered cars to cleaner electric models and rethinking operations like home heating or steel and cement production.

These efforts will need to be replicated around the world. On Monday, the International Energy Agency He said it would be published An outline in May of how the global economy will reach net zero emissions by 2050, noting that the global decline in greenhouse gas emissions last year is likely to be temporary unless countries seize the opportunity to rethink their dependence on fossil fuels.

„There will be no need for anything less than a complete transformation of our energy infrastructure,“ said Fatih Birol, the agency’s executive director. This calls for decisive action this year, next year, and in fact every year until 2050. „