Quoting the U.K. Guardian:
“James Hansen, a former White House adviser and Al Gore's science adviser, giving evidence in a British court, said sticking to a ‘business as usual’ approach would see the planet passing its climate change tipping point.”Hysteria mongering with this “tipping point” nonsense really places Hansen among the nuttiest of the nutty.
I’ve debunked this before.
Click the image and read the peer reviewed science:
Another relevant point is that every additional molecule of CO2 has exponentially LESS warming effect than the one which preceded it. Even the alarmists acknowledge this. CO2 absorbs energy at specific and relatively narrow wavelengths. Once all the energy at those wavelengths is absorbed, additional CO2 has NO IMPACT!
This is best illustrated by three different approximations of the total warming impact of CO2 from 0ppm to 600ppm (roughly double pre-industrial levels and roughly 1.6 times current levels). The previous two links, are from this page.
For more on that, see this discussion of Climate Sensitivity.