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* Facing a not-so-distant future

Mike King remembers the good old days, when it snowed more in the Skagit Valley.

“Even as a kid, when I used to live in Mount Vernon ... we used to get snow almost every year,” said King, 68, who now lives in Burlington.

“Clear Lake froze over when I was a child, and people would ice skate there,” King remembers. He also recalls snow that drifted so deep at his childhood home on the old Lyman highway that he and his sister were able to burrow tunnels down their long driveway.

“Then we would walk on it until we crashed through. As kids we had fun doing that kind of stuff,” King said.

King’s grandmother, who lived in Burlington all her life, would tell stories about the Skagit River freezing so thick that people could walk across it.

Those days are gone. If the atmospheric scientists are right, they aren’t coming back — at least not for generations to come.

As a University of Washington climate-change scientist put it, “We’re going to be in a different world.”

Scientists have plenty of hard evidence to back up the stories told by people like King and his grandmother. Temperatures have been on the rise in the Pacific Northwest and will continue to climb this century at an even faster pace.

The effects in the Skagit Valley are expected to be profound. Declining snowpack and shrinking Cascade glaciers will mean lower river flows in the summer months. Warmer winters will likely increase flows that time of year.

The impact will be felt on fish runs, agriculture and the public water supply. There will almost certainly be more demand for water in the summer, even as runoff from melting snow and shrinking glaciers is on the decline.



The ancient bank

The local effects of climate change are most visible at the edges of the glaciers.

North Cascades National Park, headquartered in Sedro-Woolley, serves as a petri dish for global warming’s influence. About one-third of all the glaciers in the lower 48 states are in the park, which encompasses much of the Cascade Range from the upper Skagit Valley to Lake Chelan.

In all, 312 glaciers cover almost 42 square miles in the park.

Glaciers keep the rivers flowing in late summer, when the runoff from the snowpack is dwindling. Scientists from Nichols College in Massachusetts who study the North Cascades glaciers report that glaciers provide one quarter of the mountain range’s summer water supply. Baker Lake and Thunder Creek, which drains into Lake Shannon, receive 40 percent of their August runoff from glacier melt.

Several studies of the park’s glaciers are happening simultaneously, including one by park scientists.

“Because they’re so immense, they deliver a lot of water to our lakes and streams at a time when we’re really dry,” said Jon Riedel, lead investigator for the park’s glacier monitoring program. “The Skagit is home to all five native species of salmon because the glaciers have provided stability — even the driest years, like the dust bowl years of the ’30s and early ’40s.”

“Glaciers also represent a reservoir of ancient snowfall, like an inherited bank account where sustained withdrawals ... outpace deposits,” Riedel said.

But in a warmer future, if the glaciers disappear, “The bank account is zeroed, and there are no more (water) withdrawals in late summer,” Riedel added.

The scientists who study the North Cascades glaciers report that they are in retreat. Park scientists figure the park has lost 40 percent of its ice cover over the last 150 years, most of which was a period of natural warming.

Park scientists and the Nichols College group measure the receding glaciers every year. Riedel and his team have measured the amount of water lost from four glaciers since 1993. Three — Noisy Creek Glacier northwest of Bacon Peak, Silver Glacier on Mount Spickard and North Klawatti Glacier south of Primus Peak — eventually drain into the Skagit River. The fourth subject in the study, Sandalee Glacier, drains into the Stehekin River on the other side of the Cascades.

The glaciers in Riedel’s study have lost more than 600 million cubic feet of water since the measurements began. A large fraction of that loss came in the last five years, because the 1990s was a decade of stability for the four glaciers.

The Nichols College team, which has measured 10 North Cascades glaciers since 1984, corroborates the Park Service results. That group found significant glacier retreat from 2000 to 2006 after a period of slight glacier growth from 1994 to 2000. The glaciers in the Nichols College study have lost 20 to 40 percent of their volume since 1984, the group reports.

A longer-term study, by Portland State University researchers, came up with a staggering number. Considering all of the 300-plus glaciers in the park, the amount of ice lost from 1958 to 1998 — most of the recognized global warming era — was 30 billion cubic feet. That’s about 35,000 gallons of water for every man, woman and child in Washington state.

Officials at Glacier National Park in Montana have famously predicted the disappearance of all the glaciers there by 2030. In the North Cascades, no such mass extinction date is discussed. If global warming can be brought under control, the largest glaciers won’t vanish, according to the Nichols College Web site.

If the climate warms another 3.6 degrees, the largest and most popular “named” glaciers should survive, the Web report said. The large glaciers make up 10 to 15 percent of the total number of glaciers in the North Cascades and 35 percent of the current glacier area.

But the smallest glaciers and many on the east side of the mountains would disappear within the next 50 years under that warming scenario, the report said. These make up 65 to 70 percent of the total glacier population in the North Cascades.



Turning up the heat

Scientists who study global warming cannot easily focus their investigations on specific communities, or even individual states. The computer programs, called global climate models, that serve as the foundation for climate change research aren’t designed to provide information on such a fine scale.

However, scientists in the Climate Impacts Group at the University of Washington pushed the results of global climate models to their limit to learn what they could about the Pacific Northwest — Washington, Oregon, Idaho, western Montana and a small part of southern British Columbia.

These researchers are trying to find out just how much temperature, rain and snowfall will change in the 21st century.

They’ve also looked back to trace the changes in regional weather during the 20th century, looking for evidence that global warming is already at work.

It may be hard to believe during a dreary Pacific Northwest winter, but data from the Climate Impacts Group suggests the rate of temperature increase in the Pacific Northwest may have been more rapid than the average global increase. Temperatures in the Pacific Northwest ramped up 1.5 degrees Fahrenheit in the 1900s.

The United Nations’ Intergovernmental Panel on Climate Change reported in February that global temperatures rose somewhere between 1.01 and 1.66 degrees from 1906 to 2005.

The 20th century had two distinct periods of warming — 1900 to 1940, and 1950 to the present. Scientists believe the earlier period was mostly natural.

Computer simulations of weather in the early 20th century show the temperature increasing even when the atmosphere was assumed to be “natural” — in other words, when the additional greenhouse gases introduced by humans are left out. Earth was coming out of one of its “mini ice ages” at that time, said Cliff Mass, an atmospheric scientist at the University of Washington.

Scientists on the U.N. climate panel are more than 90 percent certain that the warming from 1950 to the present was caused by humans and their proclivity for burning fossil fuels to produce energy. The same computer models that leave out the human-produced greenhouse gases predicted Earth would have cooled slightly since 1950 if left to its own devices.

While human-caused global warming may have begun some 50 years ago, most of the impact has yet to be felt. The Climate Impacts Group at the University of Washington predicts that temperatures in the Pacific Northwest will increase half a degree per decade through 2050, or more than three times the rate of increase observed last century.

By the 2040s, temperatures in the Northwest will be up almost three degrees over the observed average temperature from 1970-99. Given all the uncertainties that go into that number, the climate group in 2005 predicts a range of increases, from 1.4 to 4.6 degrees.

The latest temperature predictions, which haven’t been fully checked and so are not yet published, suggest the same increase, but with a wider range of variability due to a greater number of climate models used in the calculations, according to Phil Mote, a scientist with the Climate Impacts Group and the state climatologist.

Things really start to heat up by the end of the century, especially if scenarios with more aggressive economic growth are assumed.

Mass used a computer model that runs on a finer scale than the global climate models to predict the number of unusually hot days at Seattle-Tacoma International Airport. With six socio-economic scenarios devised by the climate panel to choose from, he selected the one that has people spewing out the most carbon dioxide by 2100.

If that scenario plays out, the number of days warmer than 80 degrees at Sea-Tac will go from about 28 per year in the 1990s to more than 50 per year in the 2090s. More dramatically, the number of extremely hot, 90-plus days will go from five per year in the 1990s to 17 per year in the 2090s.

But even a degree or two is enough to tip the delicate balances that determine whether a glacier grows or shrinks, or whether precipitation falls as snow or rain.



Dwindling reserves

Less snow in the mountains means more than a bummer of a ski season. The Skagit River will have 23 percent less runoff from April to September by the middle of the century as a result of the smaller snowpack, according to a prediction by the Climate Impacts Group.

Scientists have shown that global warming changes the snowpack below 6,000 feet in two ways. It becomes smaller because more precipitation falls as rain. It also melts earlier as spring arrives more quickly. Rivers respond by having their peak flows earlier in the spring, and by having higher flows in the winter and lower flows in the summer. Less precipitation is stored in the winter as snow for the summer melt.

It’s no surprise that scientists believe the snowpack has already declined, given that global warming is strongly believed to have started around 1950. Just how much the snowpack has declined is still debated, but scientists at the University of Washington are converging toward a figure of 30 percent since 1945.

Muddying the waters a bit, some scientists believe that decline was due to natural climate variability, not to human-induced global warming. It depends on what dates are being compared, Mass said.

“In the last 30 years, the snowpack has increased in the mountains,” he said.

Richard Palmer of the Climate Impacts Group estimates that the Cascade snowpack could decline another 50 percent by 2040. This assessment of the future of the snowpack meets with less controversy.

Mass also used the worst-case climate scenario for carbon emissions to predict that the snow depth at Stampede Pass, elevation 3,900 feet, will be 80 percent less in the 2090s than it was in the 1990s. Fairly soon, in the 2020s, the peak snow depth will decline by 20 percent, according to Mass’ calculations.

“There’s very little disagreement looking forward,” Mass said. “The global warming signal is going to be profound.”



More windstorms?

King, the Burlington resident who fondly remembers the snowy days of old, has also noticed a change in the winds.

“Our weather pattern is definitely changing from the early days to what we’re having today,” King said. When it snows nowadays, he said, it often warms up and melts away quickly.

“We got more northerly winds that came out of Canada and lasted for weeks” in prior decades creating those deep drifts in his childhood driveway, King said.

And the so-called Pineapple Express — the warm and rain-soaked weather system that stretches from here to Hawaii on occasion — now seems more frequent, King said.

Western Washington is also familiar with a more vigorous storm system that packs a big enough punch to knock down trees and utility poles, and threaten life and property.

Last winter, at least five damaging windstorms blew through the Puget Sound region. One, in the week before Christmas, knocked out power to 1 million utility customers and led to the deaths of at least a dozen people. This year, two bona fide windstorms had already blown through Skagit County by mid-November, and several other blustery days ended with isolated damage and power outages.

Is global warming driving an uptick in windstorms? Mass said he isn’t sure, but he suggested their numbers may actually decline as the climate warms.

The type of storm that brings those high-speed winds should actually become more intense because there will be more energy in the atmosphere to feed them. But another important factor is the storm’s path.

The peak winds in these storms could more frequently target places farther north, including Vancouver Island and mainland British Columbia, Mass said. The Canadian province bore the brunt of the severe windstorm on Nov. 12 that only brushed Skagit County.



Extinct snowmen

King’s anecdotes about all that snow when he was young are backed up by hard data. A 2006 study published by Noah Knowles of the U.S. Geological Survey showed that the fraction of wintertime precipitation that falls as snow has declined throughout the western United States, especially in western Washington, western Oregon and northern California.

While naturally occurring climate variability may be partially responsible, Knowles concluded that human-induced climate change also contributed.

Local researchers published a report more than a decade ago showing that snowfall amounts at Sea-Tac began to fall off in the 1970s.

“That has been continuing, except for 1996,” said Mass, a co-author of the 1993 snowfall study.

Even counting the snowy winter of 1996-97, the long-term trend has been for less snowfall in the Skagit Valley. The average winter snow total in Sedro-Woolley was 10.5 inches from 1931 to 1970. From 1971 to 2004, the last year good data was available, Sedro-Woolley’s average snowfall was down to 5.7 inches.

Just like the predictions for future snowpacks in the higher elevations, snowstorms over Interstate 5 during rush hour — or outside a child’s bedroom window on Christmas Eve — will become increasingly rare, scientists say.

“Twenty or 30 years from now, we’re going to be in a different world,” Mass said.


Skagit Warming Series:
Skagit Warming Page
Climate change and the Skagit Valley
Nature's Laboratory
Researchers explore effects of climate change on health
Warming's impact on Skagit water
Climate change poses threat to regional icons
Warming shifts odds away from salmon survival
Climate change could have dramatic impact on local agricultural scene
Cashing in on global warming
Warming: A rising tide
Tribe, La Conner on front lines
Green Power
Nuclear power unlikely alternative
Skagit Warming: Government action
Climate and You
What You Can Do
Why turn off the lights?
Skagit Warming: Tell us what you think


* Ralph Schwartz can be reached at 360-416-2138 or .