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Thursday, October 24, 2013

Our thanks for your comments and more on the glaciers

The last comment posted--and we welcome your feedback--came from Alba Maria as she noted the positive stories of wonderful people getting published here.  Thanks you, Alba, and we agree that is the essence of our service to viewers and listeners, and the sweetest part of our job--profiling positive stories filled with smart, passionate, game-changing people.

Are you one?  Send us your story.

In the meantime we want to post a second update on our trip to the Canadian Rockies and the material we brought back on the dwindling size and stature of glaciers--part of the environmental changes we are witnessing--and their future impact on our world.  We are publishing this directly with footnotes that are important:

1) Canadian Rockies and Coast and Columbia Mountains[edit]

The Athabasca Glacier in the Columbia Icefield of the Canadian Rockies has retreated 1,500 m in the last century.

Valdez Glacier has thinned 90 m (300 ft) over the last century, exposing barren ground near the glacial margins.[12]
In the Canadian Rockies, the glaciers are generally larger and more widespread than they are to the south in the United States Rocky Mountains. One of the more accessible glaciers in the Canadian Rockies is the Athabasca Glacier, which is an outlet glacier of the 325 km2 (125 sq mi) Columbia Icefield. The Athabasca Glacier has retreated 1,500 m (4,900 ft) since the late 19th century. The rate of retreat for this glacier has increased since 1980, following a period of slow retreat from 1950 to 1980. The Peyto Glacier in Alberta covers an area of about 12 km2 (4.6 sq mi), and retreated rapidly during the first half of the 20th century, stabilized by 1966, and resumed shrinking in 1976.[45]
The Illecillewaet Glacier in British Columbia's Glacier National Park (Canada), part of the Selkirk Mountains (west of the Rockies) has retreated 2 km (1.2 mi) since first photographed in 1887.
In Garibaldi Provincial Park in Southwestern British Columbia over 505 km2 (195 sq mi), or 26%, of the park, was covered by glacier ice at the beginning of the 18th century. Ice cover decreased to 297 km2 (115 sq mi) by 1987–1988 and to 245 km2 (95 sq mi) by 2005, 50% of the 1850 area. The 50 km2 (19 sq mi) loss in the last 20 years coincides with negative mass balance in the region. During this period all nine glaciers examined have retreated significantly.[46]


Bylot Ice Cap on Bylot Island, one of the Canadian Arctic islands, August 14, 1975 (USGS)
The Canadian Arctic islands contain the largest area and volume of land ice on Earth outside of the Greenland and Antarctic Ice Sheets[83] and is home to a number of substantial ice caps, including Penny and Barnes ice caps on Baffin Island, Bylot Ice Cap on Bylot Island, and Devon Ice Cap on Devon Island. Glaciers in the Canadian Arctic were near equilibrium between 1960 and 2000, losing 23 Gt of ice per year between 1995 to 2000.[84] Since this time, Canadian Arctic glaciers have experienced a sharp increase in mass loss in response to warmer summer temperature, losing 92 Gt per year between 2007 and 2009 .[85]

Other studies show that between 1960 and 1999, the Devon Ice Cap lost 67 km3 (16 cu mi) of ice, mainly through thinning. All major outlet glaciers along the eastern Devon Ice Cap margin have retreated from 1 km (0.62 mi) to 3 km (1.9 mi) since 1960.[86] On the Hazen Plateau of Ellesmere Island, the Simmon Ice Cap has lost 47% of its area since 1959.[87] If the current climatic conditions continue, the remaining glacial ice on the Hazen Plateau will be gone around 2050. On August 13, 2005, the Ayles Ice Shelf broke free from the north coast of Ellesmere Island. The 66 km2 (25 sq mi) ice shelf drifted into the Arctic Ocean.[88] This followed the splitting of the Ward Hunt Ice Shelf in 2002. The Ward Hunt has lost 90% of its area in the last century.[89]

Retreat of glaciers since 1850
From Wikipedia, the free encyclopedia
Retreat of Whitechuck Glacier, Washington

Glacier in Glacier Peak Wilderness, 1973
Glacier in 1973
Same place in 2006. The glacier has retreated 1.9 kilometres (1.2 mi).
Same place in 2006. The glacier has retreated 1.9 kilometres (1.2 mi).
File:Goodbye, Glaciers.ogv 

In all, about 25 percent of the ice that melted between 2003 and 2010 occurred in the Americas (excluding Greenland).
The retreat of glaciers since 1850 affects the availability of fresh water for irrigation and domestic use, mountain recreation, animals and plants that depend on glacier-melt, and in the longer term, the level of the oceans. Studied by glaciologists, the temporal coincidence of glacier retreat with the measured increase of atmospheric greenhouse gases is often cited as an evidentiary underpinning of global warming. Mid-latitude mountain ranges such as the Himalayas, Alps, Rocky Mountains, Cascade Range, and the southern Andes, as well as isolated tropical summits such as Mount Kilimanjaro in Africa, are showing some of the largest proportionate glacial losses.[1] In general glaciers are continuing to melt and retreat.[2]
The Little Ice Age was a period from about 1550 to 1850 when the world experienced relatively cooler temperatures compared to the present. Subsequently, until about 1940, glaciers around the world retreated as the climate warmed substantially. Glacial retreat slowed and even reversed temporarily, in many cases, between 1950 and 1980 as a slight global cooling occurred. Since 1980, a significant global warming has led to glacier retreat becoming increasingly rapid and ubiquitous, so much so that some glaciers have disappeared altogether, and the existence of a great number of the remaining glaciers of the world is threatened. In locations such as the Andes of South America and Himalayas in Asia, the demise of glaciers in these regions will have potential impact on water supplies. The retreat of mountain glaciers, notably in western North America, Asia, the Alps, Indonesia and Africa, and tropical and subtropical regions of South America, has been used to provide qualitative evidence for the rise in global temperatures since the late 19th century.[3] The recent substantial retreat and an acceleration of the rate of retreat since 1995 of a number of key outlet glaciers of the Greenland and West Antarctic ice sheets, may foreshadow a rise in sea level, having a potentially dramatic effect on coastal regions worldwide.

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