• COVID-19 effectively shut down large parts of the world and countries' economies.
  • The knock-on effects on US emissions were so high that total greenhouse gas levels reached the lowest point since 1990 when records began.
  • The dip brings the US within striking distance of its commitment at the Paris climate summit to bring emissions 26-28% below 2005 levels by 2025.

The last time US greenhouse gas emissions were this low, George H.W. Bush was in the White House and Ghost and Pretty Woman were at the top of the box office.

The pandemic brought 2020 emissions 10.3% below 2019 levels, according to a new analysis from the Rhodium Group. That’s the lowest level since 1990, when consistent record-keeping on US emissions began, and a steeper drop than seen during the 2009 recession.

Total US greenhouse gas emissions
Greenhouse emissions in the US reached an all-time high in 2006.
Image: Quartz

The dip brings the US within striking distance of its commitment at the Paris climate summit to bring emissions 26-28% below 2005 levels by 2025. (Though the US has formally left the agreement, president-elect Joe Biden has said he’ll make a return one of his first orders of business.) But a closer look shows that the gains are unlikely to stick once Covid-19 vaccines become widespread and the global economy recovers.

While emissions fell across most sectors (data for emissions from agriculture and land use change is not yet available, Rhodium said), the biggest drop by far was in transportation: Overall air and road passenger travel miles fell 15% below 2019. The steep drop-off in air travel was the biggest contributor, with jet fuel consumption falling 68% at the peak of lockdowns in April and May.

In other words, once travel resumes, these emissions will come right back.

Year-over-year change in emissions by sector
The transportation sector has reduced its emissions by 273 million metric tonnes.
Image: Quartz

The electric power sector, however, is a different story. There, the pandemic merely hastened pre-existing trends, chiefly the decline of coal and rise of natural gas and renewables. Those trends are likely to continue; solar and wind account for 70% of planned new power installations for 2021, according to the US Energy Information Administration.

That, plus economy-wide gains in energy efficiency, mean that the long-term trajectory of US emissions will likely continue downward even as the economy recovers.

US electricity generation by source
Coal power has fallen considerably since 2006.
Image: Quartz