Also, if the cloud is now 40km big and growing as I read someplace else, the all-vaporizing fireball would have to be ridiculous, much stronger than Tsar bomb a

Also, if the cloud is now 40km big and growing as I read someplace else, the all-vaporizing fireball would have to be ridiculous, much stronger than Tsar bomb and probably blast a massive hole in our atmosphere and all outer layers. A properly bad idea.