mmm. This guy came into my engineering class and showed us some pretty nifty things:
1. Coal obliterates alternative energies.
2. It would take massive amounts of wind/solar/hyrdo etc to replace 1/10 of the carbon usage.
3. Human's have used 5 parts of 4000 in regards to carbon based energy in the earth = No energy crisis.
4. Carbon only blocks in a specific band of radiation, which he thinks is already saturated, so more will not block in more heat.
I watched An Inconvenient Truth, and then this guy came in, and what I took from the two together is:
It's definitely happening, we can't feasibly stop our carbon usage, it might not even make a difference, so basically no matter what the cause is, it is happening.