The problem is that there's two directions this whole debate is going; one is scientific truth, the other is political 'truth'.
Scientifically, it can be shown that, on average, there has been a small increase in temperatures over time. Whether it's completely sustained, irreversible, or has happened before this, is a little harder to prove. Millions of years ago, Siberia was a huge plain of volcanic activity. That probably spewed out a lot of noxious gasses.
Carbon dioxide can be absorbed by various mechanisms over time. If the production is greater than absorption, then the net level of CO2 increases.
Now for political truth, it's just too attractive a war club to use against certain societies.
Even though it's global warming, the underlying message seems to be that the only country held to account for global warming is the US. If we just shoudered our responsibility (and a little bit more), the whole thing would 'go away'.
The overal 'resdistribution of wealth' thing works wonders. By stopping developed nations' technology in its' tracks, the less-developed nations can catch up and surpass them. You don't hear much about poor countries contributing to CO2 emissions (even though open flames are the primary method of heating and cooking there)
The biggest 'attraction' is that the whole problem is defined as one 'magic bullet' solution; sacrifice. Everything is about what you can give up, lose, do without, live a poorer (but oh, so noble) life. It's all set in a negative way, so you prove how 'cool' you are by how much worse your life is, until someone comes along and sacrifices even more, so you have to sacrifice more. I mean, c'mon, why aren't we banning carbonated beverages; we know what they put in them (to prove an 'obvious' point, and don't think someone won't try to enact this IRL...
And finally, it all supposes that only sacrifice can set things right. As I've said before, the worst thing that can happen to activism is that it succeeds. A hundred years from now, I think solutions (plural) will be found, and people will look back at us and laugh.
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anahl nathrak, uth vas bethude, doth yel dyenvey...