2016 was the hottest year yet, scientists declare

Chunks of Arctic sea ice, melt ponds and open water are all seen in this image captured by NASA’s Digital Mapping System instrument during an Operation IceBridge flight over the Chukchi Sea in July 2016. Last year was particularly bad for Arctic sea ice. (Photo by NASA/Goddard/Operation IceBridge)
Last year, global warming reached record high temperatures — and if that news feels like déjà vu, you’re not going crazy.
The planet has now had three consecutive years