Following up on Debunking Deniers of Climate Change (which is excellent, watch the video if you haven’t done so yet), a new study considers the difficulties involved with making predictions about current climate change based on historical models. And there’s the possibility of feedback loops making a bad situation worse:
An alternative is that there are additional feedbacks lurking in the system. Small temperature increases do things like melt reflective ice and put more water vapor (another greenhouse gas) into the atmosphere; as a result, they have a larger impact than might be expected. We’ve already got a number of major feedback loops incorporated into our climate sensitivity number, but there is the chance that there are other significant ones out there that we don’t know about, in which case our climate sensitivity number is too low. This is a rather worrying prospect, since it would mean that future temperature increases might be much larger than the current pessimistic projections.