That’s one of several recent conclusions about climate change that came more sharply into focus in 2020.

Parts of the world economy may have been on pause during 2020, dampening greenhouse gas emissions for a while. But that didn’t slow the overall buildup of atmospheric carbon dioxide, which reached its highest level in millions of years. 

If anything, research during the year showed global warming is accelerating. Symptoms of the fever include off-the-charts heat waves on land and in the oceans, and a hyperactive and destructive Atlantic hurricane season. 

And through November, the last year was on pace to end up as either the hottest, or second-hottest on record for the planet, almost 1 degree Celsius above pre-industrial times, inching closer to the 1.5 degree limit set by the Paris climate agreement.

Here are five aspects of climate change that were new and unexpected in 2020:

The La Niña Effect?

Some scientists noted that the persistent heating came even with the tropical Pacific Ocean tilting toward a cyclical cooling phase that suppresses the global average temperature slightly. November’s warmth across the planet was “stunning, especially considering the ongoing La Niña,” Zack Labe posted on Twitter.