After months of riots, political divisions, and the worst pandemic in a century, there is little disagreement that 2020 just might have been the worst year in modern history.

But wait, there’s more.

2020 is also tied for the hottest year on record—a fitting sendoff for Earth’s warmest-ever decade, according to the European Union's Copernicus Climate Change Service, which tracks global temperatures and the impacts of climate change.

Carbon dioxide concentrations reached 413 parts per million in May.

Worse yet, La Nina, a climate cycle that tends to bring cooling temperatures, didn’t do much to keep 2020 out of the heat. The world’s temperatures were 1.08 degrees warmer than the 1981 to 2010 average and about 2.25 degrees above pre-industry levels.

Climate scientists say the world has already inched to a new reality of hurricanes and worsening wildfires—a reality seen with increasing frequency in the United States. Worse yet, the forecast calls for drought and food shortages, particularly in the developing world.

Although the lockdowns that came with COVID-19 brought some relief from urban brown clouds of pollution, the pandemic didn’t do much on balance to curb global warming due to increasing fossil-fuel production. On the bright side, CO2 concentrations reduced last year by 7%, according to the Global Carbon Project.

While the pandemic’s impact on climate change has been minimal, and at a significant cost, there arguably may be a relationship working in the other direction. While there is little direct evidence that climate change has actually affected COVID-19 transmission, the trend of warming temperatures likely plays some role, according to Dr. Aaron Bernstein of the Harvard Chan School of Public Health.

“As the planet heats up, animals big and small, on land and in the sea, are headed to the poles to get out of the heat,” he said. “That means animals are coming into contact with other animals they normally wouldn’t, and that creates an opportunity for pathogens to get into new hosts.”

Further, Bernstein said, climate change may be have been aided the spread of the coronavirus after it jumped from animals to humans. He says that kind of scenario played out in the cases of Lyme disease and other infectious ailments.

And what about 2021?

“Future risks are not easy to foretell, but climate change hits hard on several fronts that matter to when and where pathogens appear, including temperature and rainfall patterns,” Bernstein said.

Massive wildfires that devastated vast areas in Australia, Siberia, the US West Coast and South America in 2020 have been tied to climate change Massive wildfires that devastated vast areas in Australia, Siberia, the US West Coast and South America in 2020 have been tied to climate change Photo: AFP / JOSH EDELSON