Wednesday, October 26, 2016

20 to 30 Feet Sea Level Rise Is Inevitable

Scientists have learned that the melting of the Antarctic ice sheet is accelerating.

Extreme Melting: Antarctic Glacier Lost 1000 to 1500 Feet in Thickness of Solid Ice in 7 Years

The bottom line from this study and many others is that rapid melting of the Antarctic ice sheet has started. We know from many studies of global coastlines that the last time temperatures were as warm as were 1.5 Celsius above baseline — the Paris agreement target — sea levels were 20 to 30 feet above today’s level. We now know from this study that glaciers are already melting at astonishing rates but predicting how rapidly the west Antarctic ice sheet will collapse is a major scientific challenge. Thus predicting the changing rates of sea level rise and the effects on coastlines will be controversial and political, but 20 to 30 feet (minimum) of sea level rise is pretty much inevitable. It's only a matter of time.
Although 20 to 30 feet of sea level rise will be very destructive to coastlines, efforts to slash CO2 emissions are worth doing to prevent far higher levels of sea level rise that will take place if the whole Antarctic and Greenland ice caps melt. Also, slowing down the rates of rise by limiting emissions will make mitigation efforts far easier. However, the longer we delay strong action to stop emitting carbon the greater the inevitable damage will be. Sea level rise, once set in motion, will continue for hundreds of years as the oceans and icecaps slowly move towards a new steady state. Thus the costs of delaying climate action will be extremely high over the long term.
As I've said before Goodbye Miami and New Orleans.