...A decade ago several prominent climate scientists discussed the prospects of a 4C Earth. Their concern was qualified “… if greenhouse gases do not slow down, then expect a 4C Earth by 2055.”...
...The study, prepared for the Department of Energy and Climate Change by scientists at the Met Office, challenges the assumption that severe warming will be a threat only for future generations, and warns that a catastrophic 4C rise in temperature could happen by 2060 ...
...Johan Rockström, director of the Potsdam Institute for Climate Impact Research, told The Guardian that in a 4°C-warmer world: “It’s difficult to see how we could accommodate a billion people or even half of that...
...Professor Hans Joachim Schellnhuber, then director of the Potsdam Institute, and one of Europe’s most eminent climate scientists, told his audience: “In a very cynical way, it’s a triumph for science because at last we have stabilized something –- namely the estimates for the carrying capacity of the planet [at 4°C], namely below one billion people”.
...Professor Kevin Anderson, director of the Tyndall Centre for Climate Change, believes only around 10 per cent of the planet’s population – around half a billion people – will survive if global temperatures rise by 4°C...
...James Lovelock — scientist extraordinaire, inventor of the microwave oven and propounder of the Gaia thesis — told an audience that the Earth has a fever that could boost temperatures by up to 8°C, making large parts of the surface uninhabitable and threatening billions of peoples’ lives. He said a traumatised Earth might only be able to support less than a tenth of its six billion people...
And remember, temperatures do not stop rising at 4 C. They continue to rise for centuries.
...James Hansen is the former 32 year director of the NASA Goddard Institute for Space Studies, the de facto US climate modeling agency . Hansen's team's findings show that if we were to magically halt all emissions today, and hold everything else stable, equilibrium warming in the pipeline in several hundred years is 10 C, and in 100 years it is 6 to 7 C...
Hansen's findings are important, because they were developed from paleo evidence, not modelling.
According to James Hansen, temperatures could continue to rise beyond 10 C.
...“If we burn all reserves of oil, gas, and coal, there’s a substantial chance that we will initiate the runaway greenhouse. If we also burn the tar sands and tar shale, I believe the Venus syndrome is a dead certainty.”...
A runaway greenhouse is a condition in which the earth's oceans boil away into space. Venus once had oceans, and experienced a runaway greenhouse.
