Professor Cahtah makes some good, interesting points. Among them: climate change, like peak oil, will be known with certainty only in hindsight.

The other point, which I believe he misses (sorry only watched first clip), is that our species has used this last ten thousand year period of nice weather to overshoot sustainable limits. Again in hindsight, we shall only know how far we've overshot when the next not-so-nice period arrives. I'm guessing a factor of ten or so. Come to think of it, peak oil also figures into the overshoot.

But the indisputable science behind AGW is that CO₂ does indeed scatter thermal infrared. And we are indeed increasing the level of CO₂ in the atmosphere. This effect will mean warmer nights, warmer winters, and a climate which is different than it would otherwise have been.

So let's hope for his predicted little ice age to precisely cancel the AGW event. :)