WASHINGTON – The United States’ greenhouse gas emissions from energy and industry plunged more than 10 percent in 2020, reaching their lowest levels in at least three decades, while the coronavirus pandemic has slowed the country’s economy, according to an estimate published on Tuesday by the Rhodium Group.
The sharp drop, however, was the result of extraordinary circumstances and experts warned that the country still faces enormous challenges in controlling the pollution that causes global warming. In the coming years, US emissions are expected to recover as soon as the pandemic subsides and the economy comes back to life – unless lawmakers take tougher steps to clean up the nation’s plants, factories, cars and trucks.
“The most significant reductions in the past year have been around transportation, which remains heavily dependent on fossil fuels,” said Kate Larsen, director of the Rhodium Group, a research and consultancy company. “But as vaccines become more prevalent and depending on how quickly people feel comfortable enough to drive and fly again, we expect emissions to recover, unless there are major policy changes.”
Before the pandemic hit, America’s emissions had been slowly but steadily decreasing since 2005, largely because utilities that generate electricity have been replacing coal, the dirtiest fossil fuel, in favor of cheaper and cleaner natural gas, wind and solar energy. In the past decade, utilities have retired hundreds of coal-fired power plants, despite President Trump’s efforts to revive the industry.
Then, the coronavirus arrived. As governors put their states under lockdown last spring and Americans protected themselves, emissions began to plummet in sectors of the economy that had rarely seen sustained declines before.
Transport, the country’s largest source of greenhouse gases, saw a 14.7% decline in emissions in 2020, as millions of people stopped driving to work and airlines canceled flights. While travel began to increase again in the second half of the year, as states eased their roadblocks, Americans drove 15% less miles over the past year than in 2019 and demand for jet fuel dropped by more than a third.
Emissions from heavy industry, such as steel and cement, fell 7% in 2020, as automakers and other manufacturers produced less products in the midst of the economic crisis. America’s buildings, which produce carbon dioxide when they burn oil or natural gas for heating, saw emissions drop 6.2%, driven by blockages and a warmer than average climate.
In the electricity sector, emissions fell 10.3% in 2020, driven by a sharp drop in coal burning. As demand for electricity declined across the country, utilities operated their coal plants much less frequently, 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 than coal, but still generates significant heat-trapping methane – and used more emission-free wind and solar energy.
Renewable energies increased in 2020, as energy companies overcame pandemic interruptions to build a record number of new wind turbines and solar panels before an important deadline to claim a federal tax credit. The United States produced almost as much electricity from renewable sources last year as it did from coal, a milestone that has never been reached before.
Overall, the drop in emissions across the country was the biggest decline in a year since at least World War II, the Rhodium Group said, and placed the United States at an impressive distance from one of its main climate goals under the Paris agreement, a global pact for almost 200 governments to deal with climate change.
As part of that agreement, former President Barack Obama had promised that US emissions would fall 17% below 2005 levels by 2020. President Trump repudiated the Paris pact and, before last year, it looked like the United States would not meet that goal. But in the wake of the pandemic, America’s industrial emissions are now about 21.5% below 2005 levels.
But this framework comes with several caveats. First, these figures do not account for any increase in emissions from last year’s record-breaking forest fires in the west, which burned millions of hectares of forest and grassland, sending carbon dioxide trapped in all trees into the atmosphere.
A preliminary estimate in November from BloombergNEF suggested that forest fires could offset about 3 percent of last year’s drop in American energy and industry emissions. Although many trees that caught fire will grow back, absorbing carbon dioxide as they do so, this process will take years. And scientists have warned that forest fires will become bigger and more frequent as the planet warms up.
The other caveat is that America’s emissions may increase again once vaccines are widely distributed and the economy recovers. The Rhodium Group’s report noted that a similar recovery occurred after the 2008-9 financial crisis caused emissions to drop dramatically. And he noted that many sectors, such as air travel and steel, have already recovered in recent months.
“Unfortunately, 2020 tells us little about what we can expect to see in 2021 and beyond,” concluded the report. “The vast majority of emissions reductions in 2020 were due to the decrease in economic activity and not to any structural changes that would provide lasting reductions in the carbon intensity of our economy.”
Scientists warn that even a big one-year drop in emissions is not enough to stop global warming. Until humanity’s emissions are essentially zeroed and nations are no longer adding greenhouse gases to the atmosphere, the planet will continue to heat up. As if to underline this warning, European researchers announced last week that 2020 was most likely tied with 2016 as the hottest year on record.
President-elect Joseph R. Biden Jr. called global warming a high priority, setting the goal of reducing America’s emissions to net zero by 2050. Doing so, experts say, would require important new steps to accelerate the use of renewable electricity , change Americans from gasoline cars to cleaner electric models and rethink methods for processes like home heating or steel and cement production.
And these efforts would need to be replicated around the world. On Monday, the International Energy Agency said it would publish a detailed plan in May of how the global economy could achieve net zero emissions by 2050, noting that the global drop in greenhouse gas emissions last year is likely to be it would prove temporary, unless nations embraced the opportunity to rethink their dependence on fossil fuels.
“No less than a complete transformation of our energy infrastructure will be necessary,” said Fatih Birol, the agency’s executive director. “This requires decisive action this year, next year and, in fact, every year until 2050.”