Your logic is flawed : dinosaurs died of environmental conditions that noone was able to change. Current global climate change exists because of our selfish and blind activity, and this is something we CAN change. If I take your logic, many humans died at Tchernobyl, due to a great sensitivity to radiations. Should we say, then, that we should have done nothing to protect these people ? BTW, doing nothing for our environment seems more and more dangerous for our proper survival (bees, mammals, trees, oceans, etc...). Do you have childs and think about their future ?