The “Alarmist Gone Wild” Perspective of the Increase in Antarctic Snowfall
Three days ago, Anthony posted a very factual summary of the recent EGU paper on the increase in Antarctic snowfall over the past 200 years:
Earther, the folks who reported that Gorebal Warming is deforming the seafloor, have an interesting perspective of the EGU publication (including defamatory remarks about Anthony and WUWT in the first comment)…
Antarctica Is Getting Snowier
Monday 3:50pm Filed to: ICE ON THIN ICE
The world’s largest hunk of ice, the Antarctic ice sheet, holds enough frozen water to put cities like Miami several hundred feet under. How much Antarctica shrinks in the future will depend on the balance between what’s melting away, and what’s being added when it snows.
A new study published in the journal Climate of the Past has some (small) good news as far as snowfall is concerned: it’s going up. Since the 19th century, snowfall across Antarctica has increased by about 10 percent. It isn’t nearly enough to offset sea level rise from ice melting, but the numbers are still impressive. As a press release points out, the continent is packing on about two Dead Sea’s worth of new ice each year.
“Our new results show a significant change in the surface mass balance (from snowfall) during the twentieth century,” lead study author Elizabeth Thomas of the British Antarctic Survey said in a statement.
So far, not too different than Anthony’s post… And then the wheels came off.
The dataset revealed that Antarctica gained 272 billion tons more ice per year in the first decade of the 21st century compared with the first decade of the 19th. Put another way, the additional snowfall has offset 0.02 mm of sea level rise per decade since 1800.
Since it’s unclear as to whether of not Antarctica is currently losing or gaining ice, largely due to glacial isostatic adjustment uncertainties, two Dead Seas worth of additional ice (on top of the 19th century accumulation rate) is a lot of fracking ice… If two Dead Seas worth of ice per year were disappearing from Greenland, it would be catastrophic according to the alarmists. We know this because Greenland is currently losing an estimated 186-375 billion tons of ice per year and this is described as catastrophic despite its insignificance to the overall mass and volume of the Greenland Ice Sheet (GrIS). In Greenland, our friends at Skeptical Science describe this as catastrophic…
In Antarctica, it’s described as “some (small) good news.”
One of the things I love about Alarmists Gone Wild is their total lack of perspective.
|1900–1983||75.1 ± 29.4 gigatonnes per year|
|1983–2003||73.8 ± 40.5 gigatonnes per year|
|2003–2010||186.4 ± 18.9 gigatonnes per year|
If the estimates above are correct, the Greenland Ice Sheet (GrIS) lost 11,077 billion tons of ice from 1900-2014… 81 Dead Seas. In the first decade of the 21st century (2001-2010), the GrIS lost 1,639 billion tons of ice… 12 Dead Seas.
If Antarctica was gaining an additional 272 billion tons of ice relative to the 19th century, it gained an additional 2,720 billion tons of ice from 2001-2010, more than offsetting the loss from the GrIS. It’s almost as if the ice melted from Greenland and some mystical force (evapotranspiration) transported it to Antarctica and deposited it as snowfall.
Now back to Earther…
That’s tiny compared with the several millimeters a year of sea level rise coming from Antarctica’s melting ice each year, but it ain’t nothing.
“Several millimeters a year of sea level rise coming from Antarctica’s melting ice each year”… On what planet?
adjective [not gradable ] US /ˈsev·rəl, -ər·əl/
(of an amount or number) more than two and fewer than many; some:
I’ve seen “Star Wars” several times.
Kind of difficult for melting ice from Antarctica to contribute “several millimeters a year” to 1.5-3.2 mm/yr of total sea level rise.
The IPCC Fourth Assessment Report estimated that losses from glaciers and ice caps contributed 0.58 ± 0.18 mm yr-1 to sea-level rise from 1961 to 2003 and 0.77 ± 0.22 mm yr-1 from 1993 to 2003 (Bindoff et al., 2007), with the most rapid ice losses occurring in Patagonia, Alaska, northwest United States, and southwest Canada (Lemke et al., 2007). Uncertainties in the net loss rate were significant, however, because of sparse point observations and incomplete knowledge of global glacier area and volume distribution for upscaling point observations. On the Greenland Ice Sheet, the IPCC (2007) found that mass was gained at high elevations because of increasing snowfall, and mass was lost near the coast because of increases in melting and in the flow speed of outlet glaciers. The IPCC estimated that the Greenland Ice Sheet contributed 0.05 ± 0.12 mm yr-1 to sea-level rise from 1961 to 2003 and 0.21 ± 0.07 mm yr-1 from 1993 to 2003. Changes in Antarctica were more challenging to interpret because of the relatively small changes in snow accumulation rates (Monaghan et al., 2006) and to different trends in the flow of individual West Antarctic outlet streams. The IPCC estimated that the Antarctic Ice Sheet contribution was between -0.28 and +0.55 mm yr-1 from 1961 to 2003 and between -0.14 and +0.55 mm yr-1 from 1993 to 2003, allowing for the possibility that the Antarctic mass change may have reduced sea-level rise, especially prior to 1993 (Bindoff et al., 2007; Lemke et al., 2007). The rate of ice loss appears to have increased since 1993 because of increasing surface melt on the Greenland Ice Sheet and faster flow of some outlet glaciers in both Greenland and Antarctica.
The best recent estimate is that Antarctica is somewhere between gaining enough ice to lower sea level by as much as 0.14 mm/yr and losing enough ice to raise sea level by .55 mm/yr. So… Several millimeters a year of sea level rise are not coming from Antarctica’s melting ice
Most of the extra snow has fallen on the Antarctic Peninsula, while a smaller amount accumulated on the much drier (but vaster) East Antarctic Plateau.
And this is a “good thing” because the Antarctic Peninsula is just about the only part of Antarctica experiencing a significant loss of ice mass.
On to the first comment to this article…
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