James Hansen is widely recognised
as the world’s leading climate scientist.
He calculated the 350 estimate. See the 350.org Tab.
The relentless exploitation of fossil fuels has to stop because his analysis shows that burning only a third of the proven fossil fuels could trigger a “runaway” greenhouse effect “sustained for centuries”.
Other research confirms that only a 1.5°C global temperature rise is sufficient to cause a runaway methane release. If fossil fuel burning continues at or above the current rate this will occur in 10-30 years.
Sources: See the 11/7/2013 Guardian article in the Daily News Posting list.
For James Hansen’s websites –
(This website has all of James Hansen’s research publications and also publications in the popular media).