Ocean water, heated by global warming. is melting glaciers in West Antarctica from below, potentially unpinning glaciers that have bases well below sea level. The process of melting is likely unstoppable because heat that has already entered the oceans will be released for many years according to oceanographer Doug Martinson.
What the rising water heat means, he said, is that even if humanity got organized and soon stopped emitting greenhouse gases, there is already too much heat in the oceans to stop a lot of impacts -- like the melting of a huge amount of Antarctic ice.
"There's the potential that we're locked into long term sea level rise for a long time,"
Warming oceans are destabilizing the west Antarctic ice sheet.
Warm upwelling water is melting West Antarctica's glaciers from below.
The Mercator Ocean Project's remote sensing reveals a ring of anomalously warm water encircling Antarctica at a depth of 100 meters.
Martinson said that heat stored in deep waters far from Antarctica is being pushed southward and becoming entrained in the Antarctic Circumpolar Current, a vast, wind-driven water mass that constantly circles the frozen continent. The evidence comes from 18 years of Antarctic voyages Martinson has made to measure water temperature, salinity and other qualities at different depths. He called the increases in ocean heat in the past few decades "jaw dropping." Temperatures have risen only a few degrees above the melting point–but that is all it takes to cut at the ice front. "This is like a huge freight of hot coals–fresh, hot water being delivered right to the the front door," he said.
The Oceans took up heat rapidly after the record warm year of 1998, slowing atmospheric warming while warming the waters encircling Antarctica.
The massive amounts of heat adsorbed by the oceans since 1970 will be released over many decades.
"Pretend your brains out that the politicians did something to stop global warming tomorrow. Even if they did, we will still have decades and decades of upwelling of that warmed water eating ice," he said.
The oceans have taken up massive amounts of heat since 1970. Source: Climate Progress
Fox News management has directed its "reporters" to express doubt about climate change. One of the favorite claims made by Fox "reporters" and other paid skeptics is that 1998 was the warmest year on record and it has been cooling since. In fact, atmospheric warming slowed while the oceans rapidly took up the excess heat caused by greenhouse gas increases caused by people.
In the midst of global climate change talks last December, a top Fox News official sent an email questioning the "veracity of climate change data" and ordering the network's journalists to "refrain from asserting that the planet has warmed (or cooled) in any given period without IMMEDIATELY pointing out that such theories are based upon data that critics have called into question."
The directive, sent by Fox News Washington managing editor Bill Sammon, was issued less than 15 minutes after Fox correspondent Wendell Goler accurately reported on-air that the United Nations' World Meteorological Organization announced that 2000-2009 was "on track to be the warmest [decade] on record."
While Fox News and Republican climate zombies continue to stop progress to stop climate change, greenhouse gas levels continue to rise to record levels far above the baseline for the past eight-hundred-thousand years.
Source: Professor Lonnie B Thompson (PDF)
Greenhouse gas levels far above those observed over the past 800,000 years would continue to cause atmospheric temperatures to rise if new emissions were stopped tomorrow because cold water in the deep oceans has slowed the process of temperature equilibration.
Once warmed, the ocean waters will continue to undermine Antarctica's glaciers. Because the foot of an Antarctic glacier is well below sea level, melting the foot from below can destabilize the whole glacier. Therefore, an unstoppable process has begun to destabilize Antarctic glaciers. Sea level rise caused by melting Antarctic glaciers will continue for many decades even if we take action to cut greenhouse gas emissions. However, other processes even more destructive than sea level rise can and must be stopped to prevent unthinkable amounts of suffering.
Hat tip Climate progress which links to sources of several figures.