Antarctica: Still No Time to Sell the Beach House?

With the COP 21 climate treaty conference in Paris only weeks away, federal agencies are trying harder than ever to spook the public about the so-called climate crisis.

This can be tricky when an agency-funded study indicates the state of the climate is better, rather than worse, than they thought.

A recent case in point is a NASA study by Jay Zwally and colleagues, published in the Journal of Glaciology (JOG). Their satellite data indicates that Antarctica is gaining more ice from snowfall than it is losing from coastal discharges and ice melt. In other words, currently and over the period of study, Antarctica is contributing to a net reduction in sea level rise. From NASA’s press release:

A new NASA study says that an increase in Antarctic snow accumulation that began 10,000 years ago is currently adding enough ice to the continent to outweigh the increased losses from its thinning glaciers.

The research challenges the conclusions of other studies, including the Intergovernmental Panel on Climate Change’s (IPCC) 2013 report, which says that Antarctica is overall losing land ice.

According to the new analysis of satellite data, the Antarctic ice sheet showed a net gain of 112 billion tons of ice a year from 1992 to 2001. That net gain slowed to 82 billion tons of ice per year between 2003 and 2008.

This good news conflicts not only with the IPCC’s conclusion but also with a study published in June 2014 widely hailed at the time as additional proof of the climate crisis (even though it estimated that Antarctica’s rate of ice mass loss translated into only about 1.7 inches of additional sea-level rise per century).

So how does Zwally assess the significance of his team’s finding that Antarctica is currently gaining ice mass and reducing sea level rise by 0.23 mm/year, or about 0.9 inches per century?

He says the “good news” is also “bad news.” How so? “If the 0.27 millimeters per year of sea level rise attributed to Antarctica in the IPCC report is not really coming from Antarctica, there must be some other contribution to sea level rise that is not accounted for.” OMG! The IPCC does not know where one-hundredth of an inch (0.27 mm) of annual sea-level rise is coming from.

Two questions leap to mind:

(1) Can anyone reliably measure global sea-level rise to one-hundredth of an inch? Answer: No. According to the University of Colorado Sea Level Research Group, the margin of error in satellite measurements of global sea level is 0.4 mm/year. That is larger than the alleged increment of sea-level rise for which the mighty IPCC cannot account.

(2) So is it possible the IPCC simply overestimated global-level rise by one-hundredth of an inch and there’s no missing increment to be accounted for? Answer: Yes.

Zwally further opines: “If the losses of the Antarctic Peninsula and parts of West Antarctica continue to increase at the same rate they’ve been increasing for the last two decades, the losses will catch up with the long-term gain in East Antarctica in 20 or 30 years — I don’t think there will be enough snowfall increase to offset these losses.”

So things are better than the Zwally team expected but that’s all the more reason bet on their prediction things will be worse in 20 or 30 years. Some perspective here would be useful. Sea levels rose about 8 inches in the 20th century. Whether Antarctica adds another 1.7 inches to sea level rise in the 21st century, reduces it by 0.9 inches, or produces something in between, there is no reason to believe the end is nigh.

Another new study, this one published in Proceedings of the National Academy of Sciences (PNAS), warns that if the small Amundsen Sea sector of the West Antarctic Ice Sheet (WAIS) is destabilized, “then the entire marine ice sheet will discharge into the ocean, causing a global sea-level rise of about 3 m.”

Sounds pretty scary, even though the scientists acknowledge they don’t know whether the Amundsen ice destabilization, which their model predicts will begin in 60 years, “is due to greenhouse gases and the resulting global warming.”

Let’s cut to the chase. Once destabilization begins, how long would it take for the WAIS to shed all its ice and raise sea levels by 3 meters? The authors suggest “centuries to millennia.” The PNAS press release includes a video illustrating how the ice sheet dynamics in the researchers’ model play out. As Anthony Watts notes, in the scientists’ model run, the WAIS disintegrates over a period of 9,700 years!

Click here here to watch the video. The graphics are quite cool — but don’t get spooked!

As explained in a previous post, scientists have known for some time that the WAIS is doomed. For example, Conway et al. (1999), a study published in Science, found that the grounding line (sea-floor boundary) of the Ross Ice Shelf (the largest ice shelf in Antarctica) has retreated about 1,300 kilometers since the last glacial maximum. Most of the recession “occurred in the middle to late Holocene [3,000-9,000 years ago] in the absence of substantial sea level or climate forcing.” See the picture at the top right of this post.

The Conway team speculated that complete disintegration of the WAIS “will take about 7,000 years.” That’s in the same remote futuristic ballpark as the PNAS study.

The new JOG and PNAS studies don’t change the bottom line. Now is not a good time to sell the beach house. It’s never a good time to abandon affordable energy.