No matter which way you bar the door, Darwin will find a way in.
This is nature selecting for inferior inductive reasoning, poor perception, weak analytical skills and too much conformity to consensus ideas and herd group-think. These genes have been excised from competition because they were lousy.
These people have been unconsciously "saving the planet" by avoiding reproducing themselves. It doesn't matter if the "environmental crisis" is real or manufactured (it is in fact completely manufactured out of whole cloth), their actions benefit us all. Fewer looters to shoot after TSHTF.