That is a different argument , one that needs to be made.

OP is talking about people who spout doomsday predictions.

I once had a debate with someone who was convinced that humans were going extinct in the next century. He wasn't talking about migrations of hundred of millions, deaths of tens of millions, and climate patterns of droughts and floods changing, which are all present in predictions. He really believed that every single human was going to die. There are people who literally speak bullshit doomsday philosophy.