The asteroid that caused the KT extinction burned every exposed life form, including all the land plants. The atmosphere became incandescent. Anything that sur

The asteroid that caused the KT extinction burned every exposed life form, including all the land plants. The atmosphere became incandescent. Anything that survived the inferno would have then had to deal with the clouds of ash blocking out the sun for years. It’s possible some small groups of humans could survive that, if they were survivalist types with bunkers and years of food, but it would be dicey.