Climate – Aug 29

August 29, 2006

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Washington state’s glaciers are melting, and that has scientists concerned

Les Blumenthal, McClatchy Newspapers
WASHINGTON – With more glaciers than any state in the Lower 48, Washington state has emerged as a bellwether for global warming.

The signs are not encouraging.

A national environmental group recently reported that North Cascades and Mount Rainier are among the dozen national parks most susceptible to climate change.

At Mount Rainier, which has more glacial ice than the rest of the Cascades combined and is among the best studied sites in the nation, the area covered by glaciers shrank by more than a fifth from 1913 to 1994, and the volume of the glaciers by almost one-fourth, the National Park Service says. From 1912 to 2001, the Nisqually Glacier on Mount Rainier retreated nearly a mile.

Since the first stirrings of the Industrial Revolution 150 years ago, glaciers in the northern Cascades have shrunk by 40 percent, and the pace is accelerating.
(28 Aug 2006)
Also posted at Common Dreams.


A new climate bomb ticking?
Researcher: Warming might free methane on seafloor that could accelerate the crisis

Matt Weiser, Sacramento Bee
Research on ocean sediments near Santa Barbara suggests that climate change could be accelerated by methane gas stored in oil deposits on the seafloor.

The work by Tessa Hill, an assistant professor of geology at UC Davis, documents a new source of methane gas that has not yet been factored into previous analyses of historic climate change.

The findings are potentially troubling because methane is at least 20 times more potent as a greenhouse gas than carbon dioxide, so it has the potential to make the planet hotter faster if released to the atmosphere.

Hill is the lead author of the research, published online Monday by the Proceedings of the National Academy of Sciences, a peer-reviewed journal.

She cautioned, however, that more study is needed before her findings can be applied globally. For instance, it isn’t clear how the methane would be released during climate change, and it is far from certain that similar methane stores worldwide would be freed up as sea temperatures rise.
(29 Aug 2006)
Related article in "Science Now" (AAAS): Marine Methane Heats Things Up.


Evidence of climate change in California’s Sierras

Carl T. Hall, SF Chronicle
Miniature rock glaciers. Drying meadows. Warming lakes. High-elevation studies try to predict the impact of climate change.
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Some of the world’s best evidence of global warming was buried under 18 feet of snow in the Sierra Nevada last winter, and Connie Millar was determined to dig it out.

Millar, a veteran field scientist for the U.S. Forest Service, sweated uphill with three colleagues on a July morning, headed deep into Lundy Canyon, just north of Mono Lake, one of the few access points to the Sierra crest along its rugged eastern flank.

She was hunting for rock glaciers — a cache of ice under a pile of boulders — which she suspects may be more common than realized in the Sierra. Insulated by its rocky cover, the ice is slow to melt and could become a significant source of summer water for mountain animals and plants if one of the main predictions of global warming is realized: a radical reduction in the Sierra’s snowpack.

Millar is finding and monitoring as many of these hidden ice caches as she can, to better predict how ecosystems might change as temperatures rise.

Her search for rock glaciers is just one of many investigations under way by Sierra field scientists. While some look at the interactions between insects and high-elevation plants, others monitor stream flows or study tree rings for clues to how plants responded to previous climate change. Such work adds up to one of the most ambitious scientific undertakings in California’s history: an attempt to understand how greenhouse gas emissions are affecting John Muir’s beloved Range of Light.
(27 Aug 2006)


Tropical warming
Report from Costa Rica chronicles rapid climate change

Geov Parrish, WorkingForChange
Earlier this month, I ran several letters from various North American readers recounting how global warming has already, in subtle and not so subtle ways, affected their local environments. The letters kept coming after that column ran, and one raised a particularly important point. Even though global warming has been disproportionately caused by our actions here in the United States, and even though we often think of the more severe changes thus far as having occurred in the Arctic, things are heating up all over.

Including the tropics.

Geov,

I have just finished reading your column about climate change and readers’ response, and thought I would add my own observations about what is happening here in the tropics. People think that little should change in the tropics, because they’re already warm, and two or three degrees won’t change much. But they’re wrong.

I have lived here in Costa Rica for three years, and in that short time, I have noticed quite a few changes, most confirmed by the locals as unusual or unprecedented.

For one, the rainy season is becoming less rainy. I live on the shores of Lake Arenal, Central America’s second largest reservoir, in a small town located in the mid-elevation highlands of central Costa Rica, on the continental divide. By this point in the rainy season, the reservoir should be full, but it is not this year. For the second year running, it is low to the point of where in past years it has typically been at the end of the dry season. The officials in charge of it are expressing private concerns that if this continues, there may not be sufficient water to meet the power generation and irrigation demands that the reservoir satisfies during the coming dry season.

Another thing I have noticed is that thunderstorms here are becoming noticeably more violent.
(25 Aug 2006)


Cities in peril as Andean glaciers melt

John Vidal, The Guardian
Ice sheets expected to last centuries could disappear in 25 years, threatening water supplies
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Andean glaciers are melting so fast that some are expected to disappear within 15-25 years, denying major cities water supplies and putting populations and food supplies at risk in Colombia, Peru, Chile, Venezuela, Ecuador, Argentina and Bolivia.

The Chacaltaya glacier in Bolivia, the source of fresh water for the cities of La Paz and El Alto, is expected to completely melt within 15 years if present trends continue. Mount Huascarán, Peru’s most famous mountain, has lost 1,280 hectares (3,163 acres) of ice, around 40% of the area it covered only 30 years ago. The O’Higgins glacier in Chile has shrunk by nine miles in 100 years and Argentina’s Upsala glacier is losing 14 metres (46ft) a year.

Although a few glaciers in southern Patagonia are increasing in size, almost all near the tropics are in rapid retreat. Some glaciers in Colombia are now less than 20% of the mass recorded in 1850 and Ecuador could lose half its most important glaciers within 20 years.

The rate of glacier retreat has shocked scientists, says a report on the effects of global warming in Latin America by 20 UK-based environment and development groups who have drawn on national scientific assessments. Their study says climate change is accelerating the deglaciation phenomenon.
(29 Aug 2006)