“The collapse of large parts of the ice sheet in West Antarctica appears to have begun and is almost certainly unstoppable, with global warming accelerating the pace of the disintegration,” The New York Times reports two groups of scientists stated Monday.

The finding means that a rise in global sea levels of at least 10 feet may now be inevitable, the Times goes on to say. Thomas P. Wagner, who runs NASA’s programs on polar ice and helped oversee some of the research, is quoted as saying, “This is really happening. … There’s nothing to stop it now. But you are still limited by the physics of how fast the ice can flow.”

The paper reports:

Scientists said the ice sheet was not melting because of warmer air temperatures, but rather because of the relatively warm water, which is naturally occurring, from the ocean depths. That water is being pulled upward and toward the ice sheet by intensification of the winds around Antarctica.

Most scientists in the field see a connection between the stronger winds and human-caused global warming, but they say other factors are likely at work, too. Natural variability of climate may be one of them. Another may be the ozone hole over Antarctica, caused by an entirely different environmental problem, the human release of ozone-destroying gases.

Whatever the mix of causes, they appear to have triggered a retreat of the ice sheet that can no longer be stopped, even if the factors drawing in the warmer water were to reverse suddenly, the scientists said. At this point, a decrease in the melt rate back to earlier levels would be “too little, too late to stabilize the ice sheet,” said Ian Joughin, a glaciologist at the University of Washington and lead author of the new paper in Science. “There’s no stabilization mechanism.”

Read more here.

— Posted by Alexander Reed Kelly.