Carbon dioxide emissions from the US economy are nose-diving this year to a level not seen since 1983, according to new estimates by BloombergNEF. The planet-heating pollution is on track to fall by 9.2 percent from last year, which the private research organization says would be the biggest reduction on record.

The steep drop is mostly the result of the COVID-19 pandemic upending business as usual. With many Americans working from home or no longer working, transportation — the most polluting sector in the US — had its biggest year-on-year drop ever. The sector also contributed the most to the country’s overall reduction in emissions. Power sector emissions will probably see a record drop this year, too, BloombergNEF estimates.

Globally, emissions are projected to fall by up to 7 percent this year. If those cuts were intentional and not the result of an economic and health crisis, that would be reassuring news. Greenhouse gas emissions need to keep dropping by more than 7 percent every year for the entire decade in order for the world to keep climate change at a relatively manageable level, according to United Nations scientists. For that to happen, economies need to rapidly shift to cleaner energy. Workers can’t stay home forever.

Without that intentional shift to renewables, the globe will likely continue to careen further into climate catastrophe once the pandemic is under control. After this year’s historic drop in climate pollution, BloombergNEF expects a record rise in US year-on-year emissions in 2021.

What’s also worrying is that unprecedented wildfires in the US this year have offset some of the pandemic-induced reductions in greenhouse gas emissions. Those fires unleashed 184 million tons of carbon dioxide equivalent this year, as much as about 43 coal-fired power plants might release in a year. That pollution pretty much cancels out the reduction coming from the entire power sector in 2020. Taking the fires into consideration, the US’s overall drop in emissions will probably be closer to 6.4 percent this year.

The US still has a lot of work to do to slash emissions and make those cuts permanent. The US is the second biggest carbon emitter after China, although America has historically contributed far more to the climate crisis. While the world might not have pumped out as much pollution this year as it normally does, the overall amount of carbon dioxide in the atmosphere is still growing. “Humanity’s waste pile is in the atmosphere and that doesn’t go away,” Ralph Keeling, a geochemist at Scripps Institution of Oceanography at the University of California, San Diego, told The Verge earlier this year. “The CO2 is building up in response to not just what we’re emitting right now but what we have emitted over the past century.”