Blogging while waiting to board.
Three years ago there was a sudden flurry of interest in ice in the Antarctic.
Although climate theory and the IPCC agree that global warming should cause an increase in Antarctic ice, due to increased precipitation in an area that, while warming, is still very cold, apparently the idea that somewhere, anywhere, could actually be gaining ice was anathema to some. And so there was Steig, and the GRACE measurements, and all that.
Michael Tobis recently denied that I have found peer-reviewed support for about nine different issues that we have argued about over the years. He challenged me to show him again what I have showed him before. Recreate the argument and show the links that I provided in support.
Bear in mind that I am not claiming that a) I am 100% correct or b) that the existence of a paper somewhere proves that I am right. Just that my own assumptions do have some backing in the peer-reviewed literature.
“A press release just yesterday (!) amounted to a major correction to GRACE estimates of mass flux. This is apparently a correction for isostatic rebound. It is good news because it means our worst fears that might be gleaned form the above graphs may need reconsideration.
Based on this principle, previous estimates for the Greenland ice cap calculated that the ice was melting at a rate of 230 gigatonnes a year (i.e. 230,000 billion kg). That would result in an average rise in global sea levels of around 0.75 mm a year. For West Antarctica, the estimate was 132 gigatonnes a year. However, it now turns out that these results were not properly corrected for glacial isostatic adjustment, the phenomenon that the Earth’s crust rebounds as a result of the melting of the massive ice caps from the last major Ice Age around 20,000 years ago. These movements of the Earth’s crust have to be incorporated in the calculations, since these vertical movements change the Earth’s mass distribution and therefore also have an influence on the gravitational field.
The corrected figures are reported in a multi-author paper in the Nature Geoscience by Wu et al. Quoth Wu:
According to our estimates, mass losses between 2002 and 2008 in Greenland, Alaska/Yukon and West Antarctica are 104±23, 101±23 and 64±32 Gt yr−1, respectively. Our estimates of glacial isostatic adjustment indicate a large geocentre velocity of −0.72±0.06 mm yr−1 in the polar direction. We conclude that a significant revision of the present estimates of glacial isostatic adjustments and land–ocean water exchange is required.”
This is actually picking up the story midstream, as Tobis had sounded much more worried in an earlier post. But I’m waiting for boarding call.
Here’s one source I found for my belief: “1992 to 2003, Curt Davis, MU professor of electrical and computer engineering, and his team of researchers observed 7.1 million kilometers of the ice sheet, using satellites to measure changes in elevation. They discovered that the ice sheet’s interior was gaining mass by about 45 billion tons per year, which was enough to slow sea level rise by .12 millimeters per year. The interior of the ice sheet is the only large terrestrial ice body that is likely gaining mass rather than losing it, Davis said.
“Many recent studies have focused on coastal ice sheet losses and their contributions to sea level rise,” Davis said. “This study suggests that the interior areas of the ice sheet also can play an important role. In particular, the East Antarctic ice sheet is the largest in the world and contains enough mass to raise sea level by more than 50 meters. Thus, only small changes in its interior can have a significant affect on sea level.”
The study, funded by NASA’s Cryospheric Processes Program and the National Science Foundation’s Antarctic Glaciology Program, suggests that increased precipitation was the likely cause of the gain. This was based on comparisons with precipitation model predictions over the same period of time. The most recent U.N. Intergovernmental Panel on Climate Change reported that Antarctica would gain mass due to increased precipitation in a warming climate. However, the study made no direct link to global warming.
“We need more ice core measurements from East Antarctica to determine if this increased precipitation is a change from the past or part of natural variability,” said Joe McConnell of the Desert Research Institute in Reno, Nev., who co-authored the study.
The researchers used satellite radar altimeters from the European Space Agency’s ERS-1 and ERS-2 satellites to make 347 million elevation-change measurements between June 1992 to May 2003.
The research team found there was a strong correlation between the predicted precipitation trends and measured elevation change over the 11-year period for the ice sheet, which indicated that East Antarctica’s interior was likely gaining mass due to the increased precipitation. The results, though, did not assess the overall contribution of the entire Antarctic ice sheet to sea level rise.”
This is how it was reported: “From the NY Times: “The eastern half of Antarctica is gaining weight, more than 45 billion tons a year, according to a new scientific study.
Data from satellites bouncing radar signals off the ground show that the surface of eastern Antarctica appears to be slowly growing higher, by about 1.8 centimeters a year, as snow and ice pile up.
The gain in eastern Antarctica snow partly offsets the rise in sea level caused by the melting of ice and snow in other parts of the world. The finding also matches expectations that the earth’s warming temperatures would increase the amount of moisture in the air and lead to greater snowfall over Antarctica.
”It’s been long predicted by climate models,” said Dr. Curt H. Davis, a professor of electrical and computer engineering at the University of Missouri and the lead author of a paper that was published on the Web site of the journal Science yesterday. ”This is the first observational evidence.”
The accumulation occurring across 2.75 million square miles of eastern Antarctica corresponds to a gain of 45 billion tons of water a year or, equivalently, the removal of the top 0.12 millimeter of the world’s oceans.”
Here’s another: “In the IPCC TAR Chapter 3 Executive Summary is this bullet point: “Over the period 1979 to 1996, the Antarctic (Cavalieri et al., 1997; Parkinson et al., 1999) shows a weak increase of 1.3 ± 0.2%/decade.”
And Tobis finally answers: That’s the Wingham result Fuller cites. (See Alley, Spencer and Anandakrishnan Ann. Glac. 46)
OK, there is one result that shows growing ice, which although it actually OVERLAPS the zero line, we need to take seriously because it SUPPORTS Fuller, as opposed to the GRACE data which don’t overlap the zero line but get close to it, which we are to ignore, because Fuller doesn’t like it.
Stipulate, then, that there is a study, somewhat on the early side, showing net growth of Antarctica. I would already have stipulated it, but Fuller has done us the kindness of identifying the study in question.”
This is what happens throughout the climate debate. Vampire arguments, the undead, even with a stake in their heart, are resuscitated for use at a later date. Both sides do it, but none more consistently than Michael Tobis.
Sorry to have inflicted a rant on you all. Posting will be light as I am traveling internationally for 2 weeks.