claim: An additional kick was supplied by an El Niño weather pattern that peaked in 2016 and temporarily warmed much of the surface of the planet, causing the hottest year in a historical record dating to 1880.
evidence: Marine extinction intensity during the Phanerozoic % Millions of years ago (H) K–Pg Tr–J P–Tr Cap Late D O–S Sea ice, and the cold conditions it sustains, serves to stabilize methane deposits on and near the shoreline, preventing the clathrate breaking down and outgassing methane into the atmosphere, causing further warming.