Permafrost Meets a Globally-Warmed Ocean

A surprising, astonishing image that I had never seen before. You are looking at a cross-section of Northern Arctic Permafrost undercut by a rising, warming sea and falling away.

With Global Warming, the ocean is higher and warmer now, and the shoreline shown here is retreating. Tragically, as blocks of permafrost plunge into the ocean and melt, they release a monumental amount of CO-2 from all the frozen plant and animal matter that had been locked within them for eons. This process also contributes directly to rising sea levels because the icy permafrost had been resting on bed-rock, suspended above sea level. So it is a net addition in volume when it falls.

In an another wicked mechanism found at the South Pole, warming seawater melts its way in under the “foot” of large glaciers, causing them to “calve” prematurely, dumping millions of tons of ice into the ocean. This is another positive-feedback mechanism adding to rising oceans, because the glaciers rested originally on bed-rock. They were part of the continent until they splashed in.

In another phenomenon near the South Pole, warming air masses and warmer seawater is weakening and undercutting vast floating ice-sheets that had been in place for eons. This destabilizes these gigantic floating ice-sheets and pieces as big as cities break away from shore, drift North, completely breakup and melt. Interestingly, global sea level are not affected by their dissolving. They had been floating. so when they melt, they merely replace the water that was supporting them. Also, because they are pure ice, there is no CO-2 contribution.

It is not all good news, however. Today’s massive sea-ice sheets act as a buffer against warming seawater and as they break up, they will expose South pole shorelines that have been far from the sea to the same warm water undercutting and destruction as is happening at the North Pole.