I'm not sure about global warming, but one thing is certain ; industry,chemicals and waste of all kinds have definitely messed up the world environment in a major way.
The problem with those who reject Global Warming out of hand is that this has lulled them into a false sense of security. Any one who thinks that there is no risk of environmental catastrophe sometime in the future is an idiot.
We need to adopt a common sense attitude and reject both environmental wacko extremist hysteria and the equally stupid attitude that everything is jhunky dory with the environment and that we can just go on drilling etc to our heart's content.
Consider this fact ; in the middle of the Pacific there is a giant floating mass of plastic refuse and other waste material which is THE SIZE OF TEXAS . That's scary.
No problem with overpopulation? You think that the entire world population could fit within a tiny area,such as one major city? Consider this fact. There is only a limited amount of inhabitable space on earth. There are vast areas of the world such as deserts and the arctic etc ,which are totally uninhabitable or which are incapable of supporting more than a very small population.
The earth has unlimited amounts of food, energy,fuels and water? Are you nuts?
Do you really think that the Sahara desert, the Gobi, Greenland and other inhospitable areas will ever be able to support 300 million people each? Are you nuts?
Already in America, expanding populations are encroaching on ares which were formerly inhabited only by wildlife, and this is causing serious problems between wild animals and humans, who just can't get along together.
Let's not get hysterical about environmental problems, but let's not delude ourselves into thinking that future catastrophe is impossible.It certainly isn't.