5mp Digital Camera: Climate change: cloudy, with a chance of competing realities

There's a quote attributed to Daniel Patrick Moynihan, which generally goes "Everyone is entitled to his own opinion, but not his own facts." Yet that's exactly what seems to have developed in the world of climate science. Within the mainstream scientific community, the basic physics that drives greenhouse warming hasn't been in dispute since it was discovered over a century ago, and the ability of greenhouse gasses to force climate change is apparent on other planets and within the Earth's past.

But there's an entire parallel community, one with a handful of its own scientists. There, any prediction of a measurable impact of climate change is considered unjustifiable alarmism; mainstream science is seen as colluding to stifle all countervailing evidence, as demonstrated by the e-mails stolen from the CRU. (The multiple inquiries that have cleared the scientists who sent the e-mails? Under this view, they're little more than a whitewash.)

How have two communities ended up with what are essentially different facts? It's easy to understand some of the psychology behind it, as behavior that lets us selectively accept information based on things like our group identity has been studied extensively. But many of the differences go well beyond selective filtering. They seem to arise from an entirely separate collection of raw information.