This is less about malicious people and more about tragedy of the commons. Most people don't want to see the environment destroyed, but are acting under their own incentives. If I cut down a tree it seems to makes a negligible different to the forest and my family gets to be warm that night. But if a million of us do it the forest is gone.

Multiply that by several generations and increasing power due to technology and we're here now, still under the same incentives