I tihnk theres still some confusion over 'climate change causes'. Hero, you're right about the main debate being about whether it IS human activity, or just the natural cycle of thhe planet, or some combination of the two (in which case, just how much of an effect we have). But climate change is merely the warming of the earth and the associated effects, caused by certain gasses. Although CO2 isn't the most potent greenhouse gas, its by far the largest by-product of our lifestyle. Everything produces in abundance, all living matter included.
The gases that 'freinds of the earth' and other oganisations try to curb are generally harmful to
humans and animals, NOT the planet as a whole, we just don't produce enough of them. Those are the 'polutants', CO2 isn't particularly toxic compared to them. Volcanoes produce more pollution than anything else, I have no idea why you said otherwise...just because the secondary effects of an erruption cool the earth, doesn't make them any less polluting....
My personal take on the subject is that we have simply destabalised the carbon cycle. Its a basic idea that we were taught in school from an early age. If you look at the graphs for long term atmospheric carbon concentrations....its virtually a sine wave, waxing and waning as the earth heats up, causes forest fires..lets more CO2 into the atmosphere blocking out the sun, cooling it down, then plants can grow again, taking up all the CO2 they love. I >vaguely< remember reading about the damping constant of that graph, and how it only takes a very small addition (or removal) of CO2 to set it off.
So I guess its really a case of reducing atmospheric CO2 at the cost of producing much more toxic substances, but in vastly smaller quantities, or stop the polutants, at the cost of more CO2. Ultimately: Enviromental damage (affects most animals/trees), OR climate change (affects everything). The above ultimatum is a bloody good argument for nuclear power
Blueteeth
Ps. Although it probably goes without saying, I'm just ranting and spouting opinions/idea's here. I have little evidence to back up anything, so as always, biiig pinch of salt with my posts.