VANCOUVER - The mountains of British Columbia cradle glaciers that have scored the landscape over millenia, shaping the rugged West Coast since long before it was the West Coast.

But they're in rapid retreat, and an American state-of-the-union report on climate change has singled out the rapid melt in British Columbia and Alaska as a major climate change issue.

"Most glaciers in Alaska and British Columbia are shrinking substantially," said the U.S. National Climate Assessment, released last week to much fanfare south of the border.

"This trend is expected to continue and has implications for hydropower production, ocean circulation patterns, fisheries, and global sea level rise."

According to the report, glaciers in the region are losing 20 to 30 per cent of what is melting annually from the Greenland Ice Sheet, which has received far more worldwide attention.

That amounts to about 40 to 70 gigatons per year, or about 10 per cent of the annual discharge of the Mississippi River.

"The global decline in glacial and ice-sheet volume is predicted to be one of the largest contributors to global sea-level rise during this century," the report said.

It is some of the fastest glacial loss on Earth. The cause: rising temperatures due to climate change.

"We've seen an acceleration of the melt from the glaciers," said Brian Menounos, a geography professor at the University of Northern British Columbia and one of the scientists involved in cross-border, multi-agency research into glacial loss.

There are 200,000 glaciers on Earth, 17,000 of them in British Columbia. Another 800 are in Alberta.

In B.C., researchers are keeping a close eye on the Lloyd George Icefield west of Fort Nelson, the Castle Creek Glacier near McBride, the Klinaklini and Tiedemann glaciers in the Coast Mountains, and glaciers in the Columbia River Basin.

Early results suggest these glaciers are shedding 22 cubic kilometres of ice annually, or about 22 billion cubic metres of water. For comparison, an Olympic swimming pool contains about 2,500 cubic metres of water.

"When we start to look at some of these individual mountain ranges, we're seeing some rates that are truly exceptional," Menounos said.

Similar loss is happening worldwide, and it is accelerating.

"Collectively start putting all of those numbers together, then there is the potential to raise sea level by something on the order of 30 to 40 centimetres from that ice," he said.

The U.S. Geological Service estimates that the glacier namesakes of Glacier National Park in their portion of the Rocky Mountains will disappear by 2030.

Menounos predicts that the smaller glaciers in B.C. — in the Rocky Mountains and the Interior — will be mostly gone by the end of this century.

The effects will be far-reaching, research suggests.

Glacial water is a thermal regulator in mountain headwater streams, Menounos said. Their loss will affect water temperatures, fish and the annual snow pack. That will affect the water supply and agriculture.

There could be greater potential for flooding in wet seasons and drought in dry, a particular problem in B.C., which relies on hydroelectricity to meet its energy needs.

The glacial decline in western Canada and Alaska significantly contributes to sea level rise, said the U.S. report. That's happening around the world and will only get worse, Menounos said.

"Even 40 centimetres of sea level rise will cause annual flooding for 100 million people on the planet," he said.

Glacial loss can be slowed, Menounos said. The biggest issue is human consumption of fossil fuels.

"We know what we need to do," he said. "It's not an easy decision, but we have to start, I would argue, thinking about changing our reliance on fossil fuels."

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  • This Tuesday, Feb. 22, 2011 photo shows a view of Perito Moreno Glacier in Los Glaciares National Park in Argentina. Perito Moreno is among the most accessible large glaciers and remains relatively intact even as glaciers all over Patagonia have been retreating in the past few decades. (AP Photo/Ian James)

  • In this July 19, 2011 file photo, pools of melted ice form atop Jakobshavn Glacier, near the edge of the vast Greenland ice sheet. Greenland's glaciers are hemorrhaging ice at an increasingly faster rate, but it's not the breakneck pace scientists once feared, a new study says.. (AP Photo/Brennan Linsley, File)

  • (FILES) View of the Perito Moreno glacier in southern Argentina on February 28, 2008. For the first time the glacier will rupture in winter, probably due to the climate change, Carlos Corvalan, Director of Los Glaciares National Park said on July 7, 2008. (DANIEL GARCIA/AFP/Getty Images)

  • View of the south wall of the Perito Moreno glacier February 28, 2008 in the Park and National Reservation Los Glaciares, an ecotourism destination in Patagonia, Argentina, declared by the UNESCO as Natural World Heritage Site. The glacier Perito Moreno, in the province of Santa Cruz, is one of the most significant natural attractions of Argentina 30km (20 miles) long and with a total surface of 257 km2 (160 square miles). The magnitude of this mass of ice, seems to float on lake Argentino some 70 meters (230 feet) above the water surface. (DANIEL GARCIA/AFP/Getty Images)

  • This May 30, 2012 image provided by Ian Joughin shows an iceberg in or just outside the Ilulissat fjord, that likely calved from Jakobshavn Isbrae, the fastest glacier in west Greenland. Polar ice sheets are now melting three times faster than in the 1990s, but so far that's added just less than half an inch to already rising global sea levels, a new giant scientific study says. While the amount of sea level rise isn't as bad as some earlier worst case scenarios, the acceleration of the melting, especially in Greenland, has ice scientists worried. (AP Photo/Ian Joughin)

  • In this picture taken Wednesday, July 27, 2011, Hindu pilgrims make their way to the Amarnath cave shrine over a glacier near Panchtarni, 150 kilometers (93 miles) from Srinagar, India. At least half a million devotees make the pilgrimage to the icy cave which lies 13,500 feet (4,115 meters) above sea level in Indian-controlled Kashmir amid tight security. Hindus worship a stalagmite inside the cave as an incarnation of the Lord Shiva, the Hindu god of destruction and regeneration. (AP Photo/Altaf Qadri)

  • Picture taken on September 21, 2012 near Chamonix of the 'Mer de Glace', France longest glacier, visited each year by more than 500.000 tourists. (JEAN-PIERRE CLATOT/AFP/GettyImages)

  • This 2009 photo released by Extreme Ice Survey shows Birthday Canyon in Greenland furing the filming of "Chasing Ice." The film, about climate change, follows National Geographic photographer James Balog across the Arctic as he deploys revolutionary time-lapse cameras designed to capture a multi-year record of the world's changing glaciers. (AP Photo/Extreme Ice Survey, James Balog)

  • A Picture taken on August 31, 2012 shows the Bossons glacier in the fog, near Chamonix-Mont-Blanc, French Alps, where will take place the Mont-Blanc North Face Ultra-Trail, a 168km race around the Mont Blanc crossing France, Italy and Swiss. The Ultra-Trail du Mont-Blanc (UTMB) is a mountain ultramarathon with numerous passages in high altitude (>2500m), in difficult weather conditions (night, wind, cold, rain or snow). (JEAN-PIERRE CLATOT/AFP/GettyImages)

  • A close-up view of Mendenhall Glacier, on a sunny day, on Saturday, June 23, 2012, in Juneau, Alaska. (AP Photo/Becky Bohrer)

  • In this picture taken Aug. 25, 2012, a flock of alpine sheep walk on a cliff path on the way from summer grazing high above the Aletschgletscher glacier, background, down to Belalp in the canton of Valais, during the "Schaeferwochenende" (Shepherd's Weekend) in Belalp near Blatten, Switzerland. (AP Photo/Keystone/Jean-Christophe Bott)

  • Ice chunks sit in Mendenhall Lake, in front of the Mendenhall Glacier, on Saturday, June 23, 2012, in Juneau, Alaska. (AP Photo/Becky Bohrer)

  • Spray from the heavily flowing Nugget Falls carries in front of the Mendenhall Glacier on Saturday, June 23, 2012, in Juneau, Alaska. (AP Photo/Becky Bohrer)

  • This photo provided by Bridger-Teton National Forest Avalanche Center shows a growth in snow-field volume in the Teton range of the Cody Bowl this fall over previous years. Scientists who monitor the effects of global warming are watching glaciers shrink all over the world but this year could go down as an exception in parts of the Rocky Mountains. (AP Photo/Bridger-Teton National Forest Avalanche Center, Bob Comey)

  • The tail end of the Bossons Glacier in Mont Blanc chain is pictured in the French Alps, on December 26, 2012 in Chamonix. (JEAN-PIERRE CLATOT/AFP/Getty Images)

  • Tourists in Argentina have been treated to a spectacular natural phenomenon when a major portion of the country's famed Perito Moreno glacier collapsed into Lake Argentina. Huge chunks of ice crashed into the lake below.