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Renegade 13 said:
Life didn't become extinct after that happened! That suggests to me that this whole 'global warming' thing is a natural cycle.
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Life, capital L, did not go exitnct, but many many species of life did. Some of the mass extictinctions in the past may have wiped out as many as 90% of the species. Yes life recovered, after millions of years. Nobody rational is saying we are going to wipe out all life on earth, but the question is whether we are going to make earth unihabitable for species H. sapiens.
In fact there are massive global cycles that have been going on and will continue to go on regardless of human actions. If past occurances are a good forecaster of future events, and there is no reason to think they aren't on the epoch-time scales we are looking at, then earth will get much colder and much warmer many times between now and when the sun uses up it's fuel and expands to swallow the whole thing up billions of years from now.
The question is whether our actions as a species are precipitating climactic change and speeding it up. If we have 50,000 years before the climate changes to make life here inhospitable that gives us a decent shot at achieving the technological ability to deal with it. Maybe we could get to where we really could change the climate in predictable ways, or if not we could leave and find another home, or perhaps genetically modifiy ourselves to adapt to the new conditions here.
But if through our actions we speed up that process so that the planet becomes inhospitable to us in 500 years, we are probably screwed as a species.
The question is whether or not we have the capability to effect such a change. A lot of good research says we do. There are some indications even that we've gone beyond the point where we can undo the damage we've done.
On the other hand, maybe we aren't really having an effect on the climate.
But I would rather think we are and find out later that we aren't, then think we aren't and find out later that we are.
Geoschmo