Posted on 11/04/2005 6:56:19 AM PST by EarthStomper
One of the great fears generated by global warming is that the ocean is about to rise and swallow our coasts. These concerns have been heightened by the substantial uptick in Atlantic hurricane activity that began in 1995. The frequency of really strong storms striking the U.S now resembles what it was in the 1940s and 50s, which few people (aging climatologists excepted) remember.
Those arguing that global warming is an overblown issue have been claiming for years that "consensus" forecasts of sea-level are equally overwrought. The United Nations' Intergovernmental Panel on Climate Change predicts a global average rise of from 3.5 to 34 inches by 2100, with a central estimate of 19 inches. Depending upon how you slice or dice the data, the last century saw maybe six inches.
Critics have long argued that these changes require a substantial net melting of some combination of the world's two largest masses of land-based ice, Antarctica and Greenland. In addition, they note that observed global warming is right near the low end of the U.N.'s projections, which means that realized sea level rise should be similarly modest.
Over 15 years ago, John Sansom published a paper in Journal of Climate that showed no net warming of Antarctica. While it was widely cited by critics of global warming doom, no one seemed to take notice. After all, it relied on only a handful of stations. Then, in 2002, Peter Doran published a more comprehensive analysis in Nature and found a cooling trend.
At the same time, a deluge of stories appeared, paradoxically, about Antarctic warming. These studies concentrated on the tip of the Antarctic Peninsula, the narrow strip of land that juts out towards South America. That region, which comprises less than one-half of one percent of Antarctica, is warming because the surrounding ocean has warmed.
Warmer water evaporates more moisture. The colder the land surface over which that moisture passes, the more it snows. So, Antarctica as a whole should gain snow and ice. Last year, C.H. Davis published a paper in Science about how this accumulating snowfall over East Antarctica was reducing sea level rise. This year, Duncan Wingham, at the 2005 Earth Observations summit in Brussels, demonstrated the phenomenon is observed all over Antarctica.
Greenland is more complex. In 2000, William Krabill estimated the contribution of Greenland to sea level rise of 0.13 mm per year, or a half an inch per century. That's not very much different than zero. Just last month, using satellite altimetry, O.M. Johannessen published a remarkable finding in Science that the trend in Greenland ice is a gain of 5.4 cm (two inches) per year.
Almost all of the gain in Greenland is for areas greater than 5000 feet in elevation (which is most of the place). Below that, there is glacial recession. It shouldn't be lost on anyone that because no one ventures into the hostile interior of Greenland, all we see are pictures of the receding glaciers near the coast!
The temperature situation in Greenland is more mixed than in Antarctica. Over the last 75 years, there's been cooling in the southern portion (where the recession is greatest) and some warming in the North.
The only other masses of ice on the planet that can contribute to sea level rise are the non-polar glaciers, but they are very few and far between. The biggest is the Himalayan ice cap, but it's so high that a substantial portion will always remain. Most of the rest are teeny objects tucked away in high elevation nooks and crannies, like our Glacier National Park.
If all these glaciers melted completely -- including the Himalayan ice cap -- sea level could rise no more than five to seven inches, because there's just not that much mass of ice, compared to Antarctica and Greenland.
It is simply impossible for the scientific community to ignore what is going on, even as prone to exaggeration of threats as it has grown to be. The planet is warming at the low end of projections. Antarctica is undoubtedly gaining, not losing ice. Greenland appears to either lose a little ice, or, in the recent study of Johannessen, gain dramatically. It's going to take some time for it to contribute much to rising oceans.
Meanwhile, Antarctica grows. Computer models, while still shaky, are now encountering reality, and every one of them now says that Antarctica contributes negatively to sea level rise in the next century, while almost every model now has Greenland's contribution as a few inches, at best.
It is inevitable that one of tomorrow's headlines will be that scientists have dramatically scaled back their projections of sea level rise associated with global warming. Had they paid attention to data (and snow) that began accumulating as long as fifteen years ago, they would have never made such outlandish forecasts to begin with.
References:
Davis, C.H., et al., 2005. Snowfall-driven growth in East Antarctic ice sheet mitigates recent sea-level rise. SciencExpress, May 19, 2005.
Doran, P.T., et al., 2002. Antarctic climate cooling and terrestrial ecosystem response. Nature, 415, 517-520.
Johannessen, O.M., et al., 2005. Recent Ice-Sheet Growth in the Interior of Greenland, Sciencexpress, October 20.
Krabill, W., et al., 2005. Greenland Ice Sheet: High-Elevation Balance and Peripheral Thinning, Science, 289, 428-430.
Sansom, J., 1989. Antarctic Surface Temperature Time Series. Journal of Climate, 2, 1164-1172.
Huh?
ping.
Re: Boyle's Law
The problem with the whole sea level rise due to ice melt is the fact that there is nowhere near as much ice as there was during the ice age.
At the end of the last ice age the sea level did rise by a couple of hundred feet but there isn't a miles think ice cheet covering millions of sqaure miles of land today.
Actually, Antarctica is 4.5 million square miles, with an average elevation of 8,000 feet.
98% of it is ice.
And that is being generous to the globull warming freaks.
And it's a tiny tiny fraction of the ice that once existed on the land.
I'm not sure what the average elevation is of continents not covered by glaciers. I would guess about I dunno, a thousand feet or so.
That still makes one heck of alot of ice down there.
But from all the accounts I've read, it's getting thicker, not melting.
19 May 2005 - According to a new study published in the online edition of Science, the East Antarctic Ice Sheet gained about 45 billion tons of ice between 1992 and 2003. The ice sheets are several kilometers thick in places, and contain about 90% of the world's ice.
Using data from the European Space Agency's radar satellites ERS-1 and ERS-2, a research team from the University of Missouri , Columbia , measured changes in altitude over about 70% of Antarctica's interior. East Antarctica thickened at an average rate of about 1.8 centimeters per year over the time period studied, the researchers discovered.
The region comprises about 75% of Antarctica 's total land area and about 85% of the total ice volume. The area in question covers more than 2.75 million square miles - roughly the same size as the United States.
(This means that more than 90 percent of the world's glaciers are growing thicker … while the media keeps yelling about the ones that are melting.)
Greenland icecap growing thicker
- 20 Oct 2005 - Greenland 's ice-cap has thickened slightly in recent years despite wide predictions of a thaw, scientists said today. Satellite measurements show that more snowfall is thickening the ice-cap,
especially at high altitudes, according to the report in the journal Science.
"The overall ice thickness changes are ... approximately plus 5 cms (1.9 inches) a year or 54 cms (21.26 inches) over 11 years," according to the experts at Norwegian, Russian and U.S. institutes led by Ola Johannessen at the Mohn Sverdrup center for Global Ocean Studies
and Operational Oceanography in Norway.
23 Jul 2005 - According to glaciologists, the Kangerdlugssuaq Glacier southeast of Greenland is now moving towards the sea at the "astonishing" rate of more than seven miles (12 km) per year.
The discovery came after recent measurements of the glacier were compared to those taken by NASA in 2002. During the 20th century the Kangerdlugssuaq glacier remained stable. Now it appears to be moving as much as 38 meters
(117 feet) per day.
"Glaciers act in the same way that a river does with a source and a mouth. The source is high in the mountains or at a higher latitude, where snow falls to contribute
to the source of the glacier and to feed it, allowing for advancement. This is rather like a conveyor belt, where snow falls at the top of the mountain, this additional
weight pushes the ice sheet further down, and then ends in the sea, where parts will break off to become icebergs.
The article blames the glacier's advance on "global warming."
They want it both ways, don't they? If the glaciers recede, it must be caused by "global warming." And if they advance? It must be "global warming." The trouble is that the public believes it. What a masterful piece of deception.
You can read the rest of the article, written by Matt Taylor, at
http://www.bbc.co.uk/weather/world/news/23072005news.shtml
.
It seems to me that the global warming / sea level rise advocates are trying to say that the ice that melts today could cause a similar sea level rise as after the last ice age.
It's like saying that one ice cube will fill a 5 gallon bucket with water if it melts.
The fear of which he speaks is not of his own making, he brings it in to illustrate the poor science he goes on to show.
Thank heavens for global warming! Without it, I'd have to find somewhere else to live. Talk about being in the right place at the right time- had I been here thousands of years ago, all the ice would have gotten in the way of me enjoying the fertile glacial till region that I call home!
Interestingly enough our Russian roommate tells us that the Russian people don't really put much faith or thought into global warming theories. They were just happy to have a relatively warm winter last year.
She thinks it's practically tropical here in Michigan. However the city of Cheboksary where she's from is nearly 1000 miles further north than where we live in Jackson.
SSUUURRREEEE they will (snicker, snicker). I hope the author isn't planning to hold his breath while waiting.
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