I get what they're trying to say, and it's very concerning, but the headline is slightly misleading. I think earth's hottest year would probably be during it's formation when the surface was molten rock lol
It's the hottest in 125,000+ years, likely several million, which would mean hotter than since modern humans first walked the earth. I don't think people much care that it was hotter during the Hadean Eon.