I think there were a couple a massive underwater volcanos that erupted near Africa and Tonga in the South Pacific that put a massive amount of water vapor in too oil the atmosphere. I don’t think it was reported much.

Found some links. Pretty sure volcano’s aren’t man made.🤭

https://bgr.com/science/underwater-volcano-mayotte-island-eruption/

https://www.newshub.co.nz/home/world/2019/05/massive-volcano-discovered-under-the-sea.html