Japan?
Crimate Change.
Tonga volcano.
An underwater volcano by Tonga erupted last year with tremendous output of water vapor all the way to the stratosphere and most of it is still there. Water vapor is the warmingest “gas” of all. That and the El Niño shift brought us in the Northern Hemisphere a very warm season. It will stay that way for a bit gradually cooling over the next couple of years as the water comes out of the atmosphere.