[pp.int.general] Copenhagen, our turn to dive into

[Richard Stallman]

    Still, there is no 100% certainty. Global warming may be a proven fact BUT 
    it could still be a natural temporary variation. And even if it is not, is 
    it really caused by CO2?

We know it is caused by CO2, and by methane from cattle, and maybe
other substances I don't know about.

CO2 also causes ocean acidification; see
http://www.guardian.co.uk/environment/2009/dec/10/ocean-acidification-epoca

    Finally, who are the worst wrongdoers?

That question isn't necessary, and can be a distraction, The primary
goal is not to blame someone, it is to stop the warming.

Some amount of casting blame may help achieve that goal.  I would
blame those that obstruct solving the problem.

    want to turn 
    woods into agricultural land - and grow maize for biofuels intended to save 
    the environment ...

Use of food as fuel is a totally misguided idea, and this was already
evident when governments began to promote the practice.  So why didn't
politicians consider this problem before promoting it?  I suspect it
is because they had been bought agribusiness companies that stood to
gain.