Surface melt on Greenland ice sheet
Credit: Roger Braithwaite / EarthIsland Institute
A new NASA analysis of climate change warns that the Earth’s remaining ice sheets could melt much faster than predicted, drowning even the most alarming projections by the Intergovernmental Panel on Climate Change in a sea of unprecedented disaster.
Where the IPCC chilled the world by adding two feet to sea level by the end of the century — a shift that would displace hundreds of millions of people and cause billions in damage to coastal communities — the study says a more realistic scenario might boost the waves by more than 80 feet.
Inundated by spreading meltwater and rising temps, Greenland or Antarctic ice sheets could suddenly “flip” states, disintegrate in a few decades and precipitate what the authors call it a “planetary emergency.”
The paper, written by James Hansen of the Goddard Institute for Space Studies and five co-authors, begins:
Palaeoclimate data show that the Earth’s climate is remarkably sensitive to global forcings. Positive feedbacks predominate. This allows the entire planet to be whipsawed between climate states.
One feedback, the ‘albedo flip’ property of ice/water, provides a powerful trigger mechanism. A climate forcing that ‘flips’ the albedo of a sufficient portion of an ice sheet can spark a cataclysm. Inertia of ice sheet and ocean provides only moderate delay to ice sheet disintegration and a burst of added global warming.
Recent greenhouse gas (GHG) emissions place the Earth perilously close to dramatic climate change that could run out of our control, with great dangers for humans and other creatures.
Climate change and trace gases may be the one of the most important climate discussions of the year so far, remarkable for its plain, down-to-earth language and blunt style. It needs to be read.