By JAMES GELUSO 
Shrinking glaciers spell trouble for Skagit River Lower Curtis Glacier hangs over a lip of rock on the side of Mount Shuksan, a sheet of ice spilling out of a bowl a few hundred yards wide. At the bottom of the glacier, cracks have divided the ice into impressive blue and white towers. Water - 10 million gallons a day during August - streams out from under the ice, heading down the side of the mountain into a summertime creek that eventually settles into Baker Lake below. On a warm August day, a team of three researchers made a morning's trek to the glacier. They sat on rocks next to the ice and attached crampons to their boots so they could walk across the slick surface. Just a few years ago, those rocks were covered by glacial ice. But, like most others in the Cascade Range, the Lower Curtis Glacier is shrinking. Mauri Pelto is director of the North Cascades Glacier Climate Project. He said if Lower Curtis continues shrinking at its current pace, eventually it will be replaced with a shallow lake. This year wasn't a good year for Lower Curtis. "It's already in negative mass balance now, and there's still two months of summer left." said Tom Hammond, one of the researchers who accompanied Pelto in August. If the shrinkage continues, the consequences could be disastrous. In some of the Skagit River's sub-basins, glacier runoff accounts for 40 percent of streamflow in August. Glaciers have less impact on the Skagit River as seen at Mount Vernon, where the water from 3,000 square miles passes by. But on rivers like the Baker, Sauk and Cascade, the rivers would be noticeably lower. More important, Pelto said, is the moderating effect of glaciers. In a dry summer, glacier melt can provide nearly half of a stream's water. Without that runoff, the fish and wildlife depending on a stream could be left high and dry. Some glaciers have already melted off entirely, and more are heading in that direction. And then, rivers like the Skagit will run even lower in the summer, leaving those who count on the water — from residents to farmers to fish — with less.
The prospect of shrinking glaciers alarmed the city of Bellingham, which depends on the Nooksack River for its drinking water. The city paid Pelto to study the Deming Glacier, which feeds the Nooksack, as part of a long-term water supply forecast. The trend over the past 20 years has been clear, Pelto said. There have been more warm years than cool years, and the glaciers have been shrinking. The glaciers have lost about 20 percent of their total size. They have retreated up the mountainside, and gotten thinner. Glaciers grow in the winter. Some of the snow that falls on top melts and freezes several times over a summer, eventually becoming firn, the ice that makes glaciers blue. During the summer, some of the firn melts off and the glacier shrinks. If the amount of ice that melts off is the same as the amount of new ice in a year, the glacier will stay the same size — staying in equilibrium, the glaciologists say. Glaciers often grow in a cold year, then shrink in a warm year. "The water will also be less sediment laden and warmer," Pelto wrote in an academic paper on the effects of glacial shrinkage. "The impact will be less water for the fall salmon runs, and less food in amount and processing for stream invertebrates on which salmon feed downstream in the Sauk and Skagit Rivers." Pelto conducts his studies of the North Cascades from Nichols College in Massachusetts. That may not be the best place from which to study glaciers, but it's where he has his year-round job as an environmental science professor. Each year, Pelto hikes up to the glaciers with an assistant or two. Larger glaciers, such as Easton on the south flanks of Mount Baker, get days of study. Smaller glaciers are visited once. But most of the glaciers being studied are visited every year. This year, Pelto went into the mountains with two assistants, Hammond and Tim Bartholomaus. Both are volunteers who joined Pelto out of an interest in glaciology and climate. Once they arrived on the glacier, the researchers spread out. They used lasers to measure the distances between each other as they stood at opposite ends of the glacier. They used poles to measure the depth of crevasses in the ice sheet. On some glaciers, they used dye tests, pouring dye onto the top of a glacier and clocking the time it takes to come out the other end. The glaciers are one of the clearest indicators of climate change. It's often referred to as global warming, and that's what is happening to the glaciers, but the change is more complex. One of the predictions of scientists is that the warming climate will lead to more extreme weather. In October 2003, some small areas in the higher reaches of the Skagit River basin experienced a once-in-500-years rainstorm. That was followed by one of the driest summers on record. Those two events don't prove anything, Hammond said, but they fit into the puzzle. But the warming hasn't been consistent for very long, at least not in geological terms. A spate of cool years from 1950 to 1976 had many glaciers advancing. But now they're retreating. For a glimpse of the future, Pelto points to the Lewis Glacier near Rainy Pass. In 1990, the glacier disappeared entirely, and the summertime runoff from the basin was just a quarter of what it had been when the glacier was there. Not all the glaciers will disappear, Pelto said. A larger, higher glacier like Easton will keep shrinking for several more years, but the top of the glacier is high enough that it will likely still be collecting snow each year. Eventually, it will reach an equilibrium, smaller than it is now, but not melted away completely. It's the more plentiful small glaciers that will disappear, quietly, a few feet every year. James Geluso can be reached at 360-416-2146 or by e-mail at jgeluso@skagitvalleyherald.com |
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PACIFIC
NORTHWEST: The Incredible Shrinking Glaciers
E: The
Environmental Magazine, Sept,
2004 by
Sally Deneen
So much snow. And yet ... The glacier is shrinking.
"It's very easy to see the glacier is much, much smaller," Krimmel says later, back at his office at U.S. Geological Survey (USGS). Seated at a computer, he looks at the side-by-side images--a photo taken in 1928 and another 60 years later.
"In the last century, it's retreated about 1.2 miles," says Krimmel, a research hydrologist and the glacier's leading researcher. "Right now, it's about 1.5 miles long. It's lost about half of its length and half its volume."
South Cascade Glacier has become the poster child for global climate change in the Pacific Northwest, contends Jon Riedel, glacier researcher for North Cascades National Park. It is thinning so much, Riedel points out, that since 1953 it has lost the equivalent of 72 feet of water in thickness off its surface.
It isn't the only case of the incredible shrinking glacier. In this icy high country, 46 of the 47 Cascade glaciers observed by Nichols College researcher Mauri Pelto were found to be retreating. Riedel, meanwhile, personally backpacks several miles to monitor four glaciers; he notices the lower-elevation, smaller glaciers on the west side of the Cascades are shrinking, a pattern also found farther south.
This melting promises to change the very image of the Northwest. Montana's Glacier National Park in 30 years may need to be renamed "the park formerly known as Glacier," as Seattle-based Northwest Environment Watch research director John C. Ryan puts it. A hundred of its 150 glaciers have vanished, and the pace is hastening. At white-capped Mount Rainier--that looming symbol of the Northwest (and a local beer label)--the vast majority of its glaciers are receding, says Andrew Fountain, researcher and Portland State University geology professor.
"They don't recede because they're getting colder, you know what I'm saying?" Fountain says. Whatever the ultimate cause, he says: "That's global climate change--right there."
Suffice it to say that scientists in the Pacific Northwest are seeing signs that the climate is changing, from melting glaciers to rising temperatures.
While none can definitively tie this to a human-caused, long-term shift in the climate, many believe that the changes are consistent with that. Even cautious, middle-of-the-road climate scientist Philip Mote of the University of Washington wants to "underscore" that waiting for proof before taking concrete steps to combat climate change "would not be a prudent course."
"We are seeing things that never happened before to our knowledge," says Elliott North, of the Marine Conservation Biology Institute in Redmond, Washington. "These things are consistent in what we would expect in a world that is warming. It would be, in many cases, surprising if this weren't human-caused.
"When you think of the state of Washington, do you think of marlin or yellowfin tuna? No. Well, starting several years ago, people started catching marlin, which we think of as tropical and subtropical, and yellowfin tuna off the coast of the Pacific Northwest. That is extremely peculiar," says North, adding that while El Nino was the oft-cited culprit, a warming climate is making El Nino more severe, more common, and longer lasting. Melting glaciers are concrete signs that things are changing, but aren't the only harbingers. Hikers long have enjoyed picnicking in meadows of heather at Paradise in Mount Rainier National Park, yet that, too, is in flux. As temperatures rise (the 1990s were warmer than the 1980s, and the 1980s warmer than the 1970s, says Mote), trees are filling in the park's subalpine meadows.
The trees are taking advantage of a longer growing season--eight to 10 weeks, compared to six to eight, says David Peterson, a USGS researcher and forest ecology professor at the University of Washington. "Why do people go to Paradise? To see the flowers," Peterson says. "And the flowers are starting to disappear."
Expect more change as temperatures rise faster than they have in 10,000 years--a predicted two degrees F by 2020 or 4.5 degrees by 2050, according to climate models at the University of Washington. "For the last 100 years, the Pacific Northwest has been warming and having increased rainfall. These trends are accelerating now," says Richard Gammon, a University of Washington scientist.
This spells trouble for the region's "white gold," as the mountain snowpack has been called, and for anyone dependent on the cool, clear water that rushes down glacier-fed streams in hot July and August. Global climate change threatens to eliminate half the Northwest's snowpack, according to one estimate. Glaciers are "frozen freshwater reservoirs which release water during the drier summer months," Richard S. Williams Jr. of USGS wrote in a report. "They are of considerable economic importance in the irrigation of crops and to the generation of hydroelectric power."
SALLY DENEEN is a Seattle-based freelance writer.
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Our Warming World: Effects of climate change bode ill for Northwest Juniper and honeysuckle are blooming earlier in the spring. Butterflies that can't stand a too-cold winter have taken up residence in the Tri-Cities. Snow levels are creeping higher up the sides of the Cascades. Glaciers are melting.
These indications of a warming climate already have been measured in the Pacific Northwest. Long before the U.S. Senate took up the climate-change debate two weeks ago, scientists were warning that more changes are on the way. "The time for plain speaking is long overdue," said Edward Miles, director of the University of Washington-based Climate Impacts Group. "We have never faced a problem like this." From the crest of the Cascades to the bottom of Puget Sound, this region stands in coming decades to be transformed: shorter ski seasons. More winter flooding. Reduced summer water supplies. Increasingly destructive wildfires. Further-stressed salmon runs. Never before has human society existed in a world where the concentration of heat-trapping carbon dioxide is as high as it is now -- the highest in at least 420,000 years. Earth has been warming since the mid-1800s, say more than 600 researchers who prepared the most recent United Nations-sponsored evaluation of climate change. They say what appears to be abnormally high temperatures over the past 50 years are very likely traceable to the byproducts of an industrial society, including the carbon dioxide that comes from our cars and power plants. "It's an accurate reflection of where the scientific community is to say, 'We done it,' " said Philip Mote, Washington state climatologist. "If your doctor told you there was a 95 percent chance that you were going to suffer X consequence if you don't take Y action, you wouldn't mess around hoping that 5 percent chance comes true." Scientists aren't sure how hot it will get. Much of that depends on how much people reduce emissions from factories, power plants, cars, buses and other sources of so-called "greenhouse gases" that trap heat in the Earth's atmosphere. But researchers say evidence that global warming is likely to cause major disruptions has grown considerably stronger in the past couple of years. Only a handful of scientists who have seriously studied the matter doubt that significant and potentially destructive warming is coming. This is not to say all the changes will be bad. In winter, you'll be able to breeze over mountain passes more often without chaining up. Winters, on average, will be warmer. Most springs, you'll be able to plant tomatoes earlier. But make no mistake. Things are changing already, many in ways that bode ill, from the mountains to the Sound. THE MOUNTAINSAbout a dozen snow-moving machines sit behind the Traveler's Rest convenience store at Snoqualmie Pass, waiting for the winter snowpack that draws thousands of skiers and snowboarders up Interstate 90 each winter.
Nowadays, though, managers of the Summit at Snoqualmie ski resort are looking at the sky kind of worried. While the slopes there are the most convenient to Seattle, they also sit at about 3,200 feet above sea level. That makes it the lowest Washington ski resort -- the most vulnerable to global warming. Scientists already have noted decreases in spring snowpack. With snow levels likely to rise at the rate of 300 feet for every degree of warming, a Snoqualmie skiing season that's now four months long on average stands to shrink to less than three months in 20 years, researchers say. In 40 years, it could be down to two months. Last year's opening, delayed nearly a month by lack of snow, could be a sign of things to come. Imagine -- snowless in Snoqualmie. "We rely 100 percent on natural snow," said Jon Pretty, the Summit at Snoqualmie marketing manager. "If Mother Nature isn't able to make it snow, we're de facto out of business." Snow-making equipment may not be the answer, because even that generally requires temperatures to stay in the 20s or below. "As diehard skiers and snowboarders, we think winter is already too short," said a recent appeal to Congress by a global warming-minded group of ski lodges, including Snoqualmie, called Sustainable Summits. It's not just snow that's being affected. Ice is, too. Old advertising slogans touted the North Cascades as "America's Alps." But the region's glaciers have lost some 30 percent of their girth in the last century, according to researchers from Nichols College in Dudley, Mass. They've been monitoring 117 North Cascades glaciers since 1984. All of them are receding. Seven have disappeared. A big snow year in 1998-99 helped preserve them, although the dearth of snow last year again had many shriveling. The only ones that don't seem to be on the wane are those at high elevations, near the crest of the mountain range, said Rob Burrows, a geologist at North Cascades National Park and Recreation Complex. "I don't think our glaciers are going to disappear in the next 50 years," he said. Maybe not, but Nichols College's Mauri Pelto, who has been monitoring them longer than anyone, says most could be gone by then. Just outside the park lies the continent's best-studied example of glacier-wasting. Some 25 miles northeast of Darrington, the South Cascade Glacier has lost a third of its mass in 45 years. The meltoff was particularly high from the mid-'70s to mid-'90s, reflecting a regional pattern. And U.S. Geological Survey scientists calculate that the glacier has probably lost two-thirds of its ice in the last century. At Mount Rainier, it's a similar story -- the Nisqually glacier has drawn back nine-tenths of a mile since early in the last century. A series of ice caves that drew visitors to the glacier next door, Paradise, melted away by fall 1991. These changes high in the mountains may seem profound. But really, in comparison to the rest of the problems we face, they're rather trivial. THE RIVERSDrill in hand, Craig Bates started perforating the floor in his sons' bedroom. He'd rather not damage the new addition to his mobile home, but a monster flood left him no choice. When the Skagit River swamped the streets of Hamilton last month, it left the inside of his home coated with mud and silt. Despite being elevated 5 feet off the ground, it filled with knee-deep water. The holes are needed to drain the standing water and mud. In yellow kitchen gloves and black rubber boots, four of Bates' seven children helped with the cleanup. Bates, 33, who has lived in the small town east of Sedro-Woolley nearly all his life, called it the worst flooding he'd seen. A century-old house nearby that had never been touched by a flood was soaked in more than a foot of water. "The one in '90 was bad," he said, "but it wasn't this bad." What happened last month could become more common. Climate experts predict that in the Northwest, climate change will bring wetter, warmer winters, increasing the risk of flooding. In the summer, rivers will likely run lower and warmer -- causing even more problems. In the mountains, the snowpack acts like a bank. Water is deposited in fall and winter. It's withdrawn gradually over spring and summer as it melts and feeds streams. Warmer temperatures are expected to cause less of the precipitation to fall as snow, and more as rain, triggering earlier melting and depleting the snow sooner. These "rain-on-snow events" also are famously related to an increased risk of landslides. Melted snow provides water for drinking, irrigation and maintaining river flows for threatened salmon. With snowpack becoming an unreliable investment, some water managers are looking for a safer place to put their aquatic savings. They're looking underground. In Federal Way, officials with the Lakehaven Utility District hope one day to take water from the Green River when flows are high and pump it underground so it can be withdrawn when the mercury rises. "Global warming is something that will reduce snowpacks, but not necessarily the rain we receive," said John Bowman, Lakehaven's water manager. "Storage becomes the key." The utility is applying for permits so that the trial project can become a permanent resource. The aquifer can hold 9.5 billion gallons of water -- enough to fill Green Lake 23 times. Seattle Public Utilities is in the middle of a two-year study with the UW's Climate Impacts Group to learn how climate change could alter water supply and demand. SPU now relies primarily on river water held in reservoirs and channeled to local faucets through diversion dams. Dams statewide are blamed for disrupting river flow, withholding water needed by salmon and hindering their passage. Climate change could greatly exacerbate this problem. Or, with a massive shift in priorities, dams could lessen global warming's anticipated harm to fish. On the Columbia River and its tributaries, water is released through the dams in the winter to produce energy when heaters click on and the region needs it the most. Power demand decreases in the summer and lake reservoirs are refilled for public recreation and to get ready for winter. This strategy could be shifted. By storing more water through the winter, dam operators would have additional water available to compensate for the diminished snowpack and help salmon survive. Such a major change would require approval from dozens of U.S. and Canadian dam operators. It likely would reduce power production and require a shift away from hydro to other energy sources. Some summer fishermen would be stranded by boat launches left high and dry. Dam operators have resisted efforts to increase summer flows. As a result, dams already are being operated in July and August at flows below goals set for saving threatened Columbia salmon. Analysts are researching the potential effects of climate change on this river system and what effect a shift in dam operations could have. Drawing down reservoirs in the summer could also help reduce fall flooding. It's too late to lessen Bates' hardship. Though he has deep roots in Hamilton, where his father is the mayor, he may pull up stakes to avoid an encore. "I'm ready to move," said his 14-year-old daughter, Krissi. "This is too much to handle."
P-I reporter Lisa Stiffler can be reached at 206-448-8042
or
lisastiffler@seattlepi.com
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