MONTANA EXPERTS SAY CLIMATE CHANGE UNDERWAY IN MUCH OF WESTERN U.S.
By Lorna Thackeray
Billings Gazette / Mont. Knight Ridder/Tribune Business News
April 8, 2004
http://www.miami.com/mld/miamiherald/business/national/8388980.htm
Early snowmelt has become a hallmark of Montana's prolonged drought.
Some scientists are beginning to think that it may be much more than that.
Full-fledged climate change, which could mean shorter winters and drier summers, is already under way across the Western United States, said Steve Running at the University of Montana.
"We have every reason to believe that it will continue or even accelerate," he said. "Absolutely, we are in a multidecadinal change in climate."
Running is director of UM's Numerical Terradynamic Simulation Group, which makes software for NASA's environmental satellites. The group operates the Montana Climate Center, which opened last fall in Missoula.
Evidence collected over the last 50 years suggests that rising temperatures have fostered a decline in springtime snowpack of 15 to 30 percent in Montana and that springtime peak river flows now come an average of two weeks earlier, he said.
The snowpack, which holds about 75 percent of the West's water supply, acts as a reservoir that keeps streams flowing in the summer months. If the melt continues to recede earlier into spring, resulting summer water shortages could affect everything from agriculture and hydropower to fish habitat, the professor said.
It's a fear that he shares with Belgrade native Kelly Redmond, Western regional climatologist for the National Oceanic and Atmospheric Administration Climate Center in Reno, Nev.
The degree of change in spring melt varies, Redmond said, but the trend toward earlier melt is widespread across the West. Yellowstone Basin snow begins to melt five to 15 days earlier than it did 56 years ago.
The trend becomes more pronounced as waters flow west. West of the Divide in Montana and into Idaho, Washington and Oregon, spring melt comes 15 to 25 days earlier, Redmond said.
"It's kind of taken us all aback," he said in a telephone interview. "It's kind of hard to see this happening right under our nose without us noticing."
Only in the last few years has early snowmelt drawn much interest, he said, but he expects to see research and public information on the trend accelerate.
Evidence for earlier melts is strong on a lot of fronts, Redmond said.
At the top of the list are temperature statistics. Records indicate that America is warming, especially in the West, and especially in February, March and April. For most of the West, Montana included, temperatures during that critical period have increased a half-degree to a full degree every decade for the last 30 to 40 years.
March 2004 stands out as a prime example, Redmond said. It was an
"exceptional" month, the climatologist said.
All across the West, it was warm and dry. For south-central Montana, 2004 produced the fourth-warmest March since 1895. It was also among the driest.
"Normally, March is a snow production month," he said. "But this year it was a deficit month."
Montana wasn't alone in its lack of snowpack. Utah started the month expecting near average spring runoff for a change, Redmond said. By the end of the month, the state was bracing for one of the lowest runoffs ever.
Statistics from Natural Resources and Conservation Service snow surveys show that snowpack declined 16 percent in Montana between March 1 and April 1. The losses were more severe elsewhere in the West, including Nevada, 54 percent; Arizona, 51 percent; New Mexico, 43 percent; Utah, 39 percent; and Wyoming, 19 percent.
A warm March and a warm winter worked together. In Montana, the average temperature from October through March was 3 degrees above normal -- the 11th-warmest winter on record. Even winter-ravaged northeastern Montana surpassed its winter average by 1 degree.
Running said that studies of the Missoula area showed the number of frost-free days has increased 15 days there in the last 50 years and that annual snowfall has fallen from an average of 55 inches to 40 inches.
Related, but separate evidence of earlier snowmelt comes from studying peak spring flows for more than 1,000 streams in the Western states, Western Canada and Alaska over the last 50 years, Redmond said. Those studies show snowpack disappearing from one to three weeks earlier in the spring.
What researchers measured was the "spring pulse" of all those streams.
Snowmelt begins after the pack has ripened, Redmond said. It accumulates enough heat that the entire pack reaches 32 degrees, before it starts to melt.
"When the snow begins to melt, it does it in a fairly abrupt fashion,"
Redmond said.
Scientists can go back through streamflow records and mark the date when the water starts to come down -- that's its spring pulse. Records show that the pulse happens almost simultaneously throughout the region. The pulses kick in usually within two or three days of each other, he said.
Research shows that, from New Mexico to Alaska, the pulse is getting earlier, Redmond said. This spring a river gauge in California's Yosemite National Park recorded the spring pulse on March 6, the earliest ever in 87 years of monitoring.
A third body of evidence originated more than 40 years ago when then-Montana Climatologist Joe Caprio began collecting data on the life cycles of lilacs and honeysuckle, Redmond said. Caprio recruited 500 observers in 11 states to record when the plants first showed signs of life in the spring and when they blossomed.
Analysis of the information indicated that the plants are blooming seven to 10 days earlier now than they did 40 years ago, Redmond said.
"They all kind of give a consistent pattern," he said of the temperatures, spring pulses and blooming dates.
Warmer springs and earlier melts mean a longer growing season and that plants will be using more water, Redmond said. It may also mean that more moisture will go directly into the atmosphere, he said.
"The major thing to sort out here has been whether this is a natural
variation in climate or if it is something else," he said. "There is strong evidence that a good part of it is natural."
For Running, the debate has already been resolved. He said human activity is clearly playing a significant role in climate change.
"We'd better start getting serious about energy that's not based on
petroleum," he said.
If the world community doesn't find some solutions, consequences will be dire, Running said.
"People are going to have to face up to it head on or get used to less and less snowpack and more and more drought," he said.
Informant: NHNE
Billings Gazette / Mont. Knight Ridder/Tribune Business News
April 8, 2004
http://www.miami.com/mld/miamiherald/business/national/8388980.htm
Early snowmelt has become a hallmark of Montana's prolonged drought.
Some scientists are beginning to think that it may be much more than that.
Full-fledged climate change, which could mean shorter winters and drier summers, is already under way across the Western United States, said Steve Running at the University of Montana.
"We have every reason to believe that it will continue or even accelerate," he said. "Absolutely, we are in a multidecadinal change in climate."
Running is director of UM's Numerical Terradynamic Simulation Group, which makes software for NASA's environmental satellites. The group operates the Montana Climate Center, which opened last fall in Missoula.
Evidence collected over the last 50 years suggests that rising temperatures have fostered a decline in springtime snowpack of 15 to 30 percent in Montana and that springtime peak river flows now come an average of two weeks earlier, he said.
The snowpack, which holds about 75 percent of the West's water supply, acts as a reservoir that keeps streams flowing in the summer months. If the melt continues to recede earlier into spring, resulting summer water shortages could affect everything from agriculture and hydropower to fish habitat, the professor said.
It's a fear that he shares with Belgrade native Kelly Redmond, Western regional climatologist for the National Oceanic and Atmospheric Administration Climate Center in Reno, Nev.
The degree of change in spring melt varies, Redmond said, but the trend toward earlier melt is widespread across the West. Yellowstone Basin snow begins to melt five to 15 days earlier than it did 56 years ago.
The trend becomes more pronounced as waters flow west. West of the Divide in Montana and into Idaho, Washington and Oregon, spring melt comes 15 to 25 days earlier, Redmond said.
"It's kind of taken us all aback," he said in a telephone interview. "It's kind of hard to see this happening right under our nose without us noticing."
Only in the last few years has early snowmelt drawn much interest, he said, but he expects to see research and public information on the trend accelerate.
Evidence for earlier melts is strong on a lot of fronts, Redmond said.
At the top of the list are temperature statistics. Records indicate that America is warming, especially in the West, and especially in February, March and April. For most of the West, Montana included, temperatures during that critical period have increased a half-degree to a full degree every decade for the last 30 to 40 years.
March 2004 stands out as a prime example, Redmond said. It was an
"exceptional" month, the climatologist said.
All across the West, it was warm and dry. For south-central Montana, 2004 produced the fourth-warmest March since 1895. It was also among the driest.
"Normally, March is a snow production month," he said. "But this year it was a deficit month."
Montana wasn't alone in its lack of snowpack. Utah started the month expecting near average spring runoff for a change, Redmond said. By the end of the month, the state was bracing for one of the lowest runoffs ever.
Statistics from Natural Resources and Conservation Service snow surveys show that snowpack declined 16 percent in Montana between March 1 and April 1. The losses were more severe elsewhere in the West, including Nevada, 54 percent; Arizona, 51 percent; New Mexico, 43 percent; Utah, 39 percent; and Wyoming, 19 percent.
A warm March and a warm winter worked together. In Montana, the average temperature from October through March was 3 degrees above normal -- the 11th-warmest winter on record. Even winter-ravaged northeastern Montana surpassed its winter average by 1 degree.
Running said that studies of the Missoula area showed the number of frost-free days has increased 15 days there in the last 50 years and that annual snowfall has fallen from an average of 55 inches to 40 inches.
Related, but separate evidence of earlier snowmelt comes from studying peak spring flows for more than 1,000 streams in the Western states, Western Canada and Alaska over the last 50 years, Redmond said. Those studies show snowpack disappearing from one to three weeks earlier in the spring.
What researchers measured was the "spring pulse" of all those streams.
Snowmelt begins after the pack has ripened, Redmond said. It accumulates enough heat that the entire pack reaches 32 degrees, before it starts to melt.
"When the snow begins to melt, it does it in a fairly abrupt fashion,"
Redmond said.
Scientists can go back through streamflow records and mark the date when the water starts to come down -- that's its spring pulse. Records show that the pulse happens almost simultaneously throughout the region. The pulses kick in usually within two or three days of each other, he said.
Research shows that, from New Mexico to Alaska, the pulse is getting earlier, Redmond said. This spring a river gauge in California's Yosemite National Park recorded the spring pulse on March 6, the earliest ever in 87 years of monitoring.
A third body of evidence originated more than 40 years ago when then-Montana Climatologist Joe Caprio began collecting data on the life cycles of lilacs and honeysuckle, Redmond said. Caprio recruited 500 observers in 11 states to record when the plants first showed signs of life in the spring and when they blossomed.
Analysis of the information indicated that the plants are blooming seven to 10 days earlier now than they did 40 years ago, Redmond said.
"They all kind of give a consistent pattern," he said of the temperatures, spring pulses and blooming dates.
Warmer springs and earlier melts mean a longer growing season and that plants will be using more water, Redmond said. It may also mean that more moisture will go directly into the atmosphere, he said.
"The major thing to sort out here has been whether this is a natural
variation in climate or if it is something else," he said. "There is strong evidence that a good part of it is natural."
For Running, the debate has already been resolved. He said human activity is clearly playing a significant role in climate change.
"We'd better start getting serious about energy that's not based on
petroleum," he said.
If the world community doesn't find some solutions, consequences will be dire, Running said.
"People are going to have to face up to it head on or get used to less and less snowpack and more and more drought," he said.
Informant: NHNE
Starmail - 11. Apr, 09:14
