Science

they will tell you that many dinosaurs went extinct way before the Doomsday asteroid "killed' them.

If we listen to bird experts and we should, they will tell you some others already had feathers and possible flight.
Underground caverns may protect and tall mountain ranges, stuff you do not usually find in small lab experiments designed to mimic the aftermath.

Finally they see the light that not all plants can go for years on end without sunlight. Eddies opening up possible survival areas.