This thread amazes me.
You would think that people who grow pot plants in closets would understand what kind of impact a 5 C rise in temperatures would have on food production.
There are many pollutants that occur naturally. Carbon monoxide would be one example.
Burning fossil fuels, as we are doing right now, is not sustainable as a source of energy. So even if you close your eyes to the greenhouse effect and co2 emissions, you need to acknowledge that something has gotta give. I think science will help us overcome this problem at some point and I'm definitely in favor of using more nuclear power, but you guys need to stop deluding yourselves into thinking we can go on doing what we're doing without consequences.
We still have time to start making better decisions, but you need to acknowledge the problem. Check out a book called "collapse" by jared diamond, it's a really good read. He talks about past civilizations that fell apart due to environmental factors.