N8G and others,
I agree that nature will find a "statis that is sustainable" and eventually equalize, but the problem with this statement is that this new "equilibrium" may not be so human-friendly. I also agree with your belief that man most likely won't go extinct, however rising sea-levels, rising ocean temperatures, increasingly violent storms, etc. will inevitably kill large numbers of people or strip them of their homes.
In any case, I believe the issue is not human extinction, nor nature finding an equilibrium, but rather humans learning to co-exist with nature. With our smog, mass deforestation, exponential population growth, etc. we are becoming "a force of nature" (a quote from the movie). We can't expect nature to always neutralize everything and anything we throw at it. There is a limit to how much smog and trash nature can handle and I believe we are reaching that limit. Being the force that we are, I believe we must take steps to cooperate with nature.
Humans have always had a tendancy to look at nature as a resource to be used, exploited, and controlled..and I understand to some extent, we must use nature to survive. But eventually, every resource runs out. If nature "runs out" we will die. It's not the same as oil running out or coal running out since there are alternatives. The problem is, there is no alternative to nature, to earth. We must change our perspective of nature as a resource.
Let me explain...
Now, this may be getting a little too fundamental or philisophical, but I believe it's important to notice (if you haven't already). Humans are an anomoly of nature. All other animals on earth are limitted to their specific habitat since they lack the innovation and the ability to adapt (without evolution). Humans are not limitted. If there is no food in a certain area, we can devise ways to grow food or transport food. If its too hot, we have AC. If there is a shortage of anything, we can find ways to increase the supply or find replacements. Nature will never and can never "adapt" to a species that has no limits and continuously grows. Since we cannot live without nature, we must take steps to find an equilibrium with nature. Because humans are an anomoly, this equilibrium will not happen naturally. The only way to find true equilibrium is if we go extinct, or if we start to respect nature and reflect that respect in action.
Even if global warming is a "theory", we must understand that for anything to be a theory, it must be supported by facts (the theory of evolution, for example). Any theory that threatens earth should not be considered lightly, even if it is "just" a theory. The risk is too great. We only have one earth. Sadly, we will probably just keep living our normal everyday lives anyways.
P.S. in response to earlier posts saying that global warming is all a cyclical: Is it just coincidence that at the current rate, this cycle will be the shortest and hottest cycle in earth's history? Maybe it is coincidence, maybe it isn't, but it sure does not make me feel good.