RealClimate reviews a 1981 attempt to forecast the climate impact of CO2 emissions, and finds that it's basically pretty good (see also The Register eating their words slowly). Which is what you'd expect - the physical processes involved aren't that complicated at that sort of low-earth orbit viewpoint, and the only things that could really go wrong would be some sort of huge data collection problem or else a really big volcano.
That was James Hansen's work, and this week he got an Easter egg! Rather, the US Environmental Protection Agency issued a draft regulation that basically means you can't build a new coal-fired power station. This may be the best news anyone's had for some time.