Letter by 40 scientists - the gory details
New studies reported by leading climate scientists indicate the Greenland and west Antarctica ice caps would, if atmospheric CO2-equivalent concentrations reached 450 ppm, very likely melt rapidly, raising sea-level on the scale of metres per century.
I guess by "leading climate scientists" he means his mates at the IPCC. He then goes on to quote from a letter by arch-alarmist James Hansen to Kevin Rudd:
Global climate is near critical tipping points that could lead to loss of all summer sea ice in the Arctic with detrimental effects on wildlife, initiation of ice sheet disintegration in West Antarctica and Greenland with progressive, unstoppable global sea level rise, shifting of climatic zones with extermination of many animal and plant species, reduction of freshwater supplies for hundreds of millions of people, and a more intense hydrologic cycle with stronger droughts and forest fires, but also heavier rains and floods, and stronger storms driven by latent heat, including tropical storms, tornados and thunderstorms.
Wow, sounds like something out of the Old Testament - and only marginally less credible as well. The only thing he doesn't mention is plagues of locusts. He finishes with the "End of the World" conclusion:
We must face the challenge and seize the opportunities in dealing with climate change. We face a choice between climatic disasters and directing resources to stabilise the Earth’s climate for future generations. We need to invest in low-carbon technology and we need to do it now.
Read it here (if you must).