It's always remarkable how people can rationalize whatever they find it convenient to believe, or disbelieve, into something ultimately self-serving and selfish. One of the most common rationalizations is tricking oneself into believing that one's actions have no consequences. That's never been true in any other arena, so it's reasonable to expect it to be untrue as well amongst those who would deny any responsibility for environmental changes brought about by their actions.
Well, I can't imagine how it can be easy to convince oneself that one's actions have no consequences. But I remember that in the late 1970s and early 1980s there was big dispute in Bucks County over a pumping plant. Claims were made that if the pump were installed, the water level in the Delaware would drop, the salt line would move appreciably upriver, and the fish population would sharply decline. When an environmental scientist was brought in by both sides to evaluate the matter and concluded there was nothing to these fears, those who had made the claims turned on him. But he proved to be right. The pump was built. The water level was unaffected, the salt line is where it always was, and the fish are thriving -- in fact, the shad are back in great numbers.