The aim to limit global warming to two degrees of pre-industrial levels is "crazy" and "a prescription for disaster", according to a long-time NASA climate scientist.

The paleo-climate record shows sea-levels were six to eight metres higher than current levels when global temperatures were less than two degrees warmer than they are now, Professor James Hansen, formerly head of NASA's Goddard Institute for Space Studies and now at Columbia University in New York, said.

Antarctica's ice sheets are melting faster than models predicted, James Hansen says Credit:Alex Cornell

"It's crazy to think that 2 degrees celsius is a safe limit," Professor Hansen told RN Breakfast on ABC Radio on Tuesday, adding that this would lock in several metres of sea-level rise by the middle of the century,

New satellite data over the past decade indicate that the ice sheets are disintegrating faster than had been modelled by climate scientists.