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Colorado's Dusty Snow
Article
Nathan Bilow/AP Photo
How will dust from the desert affect the clean snows of Colorado?
DENVER, Colorado (Achieve3000, June 26, 2007). There are serious and dangerous environmental changes
taking place in Colorado. The consequences could affect more than just the skiers and snowboarders who come
to the Centennial State for its famously clean and deep snows. A recent study in Geophysical Research
Letters says that ranching, mining, and energy exploration in many western states are sending clouds of dust
blowing onto the high mountain snowpacks. This is causing accelerated melting of snow in the Colorado
mountains. Because Colorado's snow-capped mountains are a significant source of the state's water, the dust
can have serious consequences for the state's residents.
During warmer months, normal seasonal climate change causes meltwater to run down Colorado's mountains,
irrigating its farms and filling its city and town reservoirs. In cooler months, the mountain snowpack serves
another essential function. In a process called the "albedo effect," the white expanses of snow reflect the sun's
heat back into outer space. This helps regulate Earth's temperature. The process is curtailed when dust covers
the snowpack.
According to Stephanie Renfrow of the National Snow and Ice Data Center (NSIDC) at the University of
Colorado in Boulder, "White snow reflects most of the sun's rays, while the dusty snow absorbs more of the
sun's energy." Since the dusty, darker-colored snow absorbs the sun's heat more quickly than white snow, it
also melts more quickly. That's bad news for Colorado residents. By the summer's hottest months they are
growing worried about the dwindling water supply.
Tom Painter of the NSIDC said that the wind-blown dust is coming from the Colorado Plateau, 200 miles
southwest of Colorado's San Juan Mountains. He explains that until large-scale human settlement, grasses held
most of the dust in place. One hundred years of human activity has disturbed the desert crust, with ranching,
mining, and energy exploration worsening the problem. Now, dust blows freely.
Computer models and ground data show that dusty snow melted 24 to 35 days earlier last year, when the dust
was heavy, than in dust-free years. Said Painter, the author of a study on dust and snow, "The snowpack 150
years ago was probably much cleaner, and by being cleaner, it lasted longer, potentially weeks longer."
According to Painter's study, the number of dust storms from Arizona and New Mexico that covered
Colorado's San Juan Mountains with dust in 2006 was double that of years past.
Painter calls the phenomenon a global problem, saying, "Around the world but particularly in the Southwest, it
appears that dust emission has increased." Researchers have also found evidence to support Painter's concern.
Studies have proven that windstorms are increasingly coating Antarctica's high peaks with dust blowing in
from nearby Patagonia. In Patagonia, dust is the result of extensive sheep grazing, which has damaged the soil.
Painter himself has observed dust-laden snow in the Alps and in the Tien Shan Mountains in China. He worries
that the same will hold true for the Himalayas and other snowy ranges around the world.
The Associated Press contributed to this story.
Dictionary
curtail (verb)
to decrease; to cut back
Colorado's Dusty Snow
Activity
PAGE 1

1. According to the article, what is the effect of the premature melting of the Colorado snowpack?
Meltwater used for irrigation and filling reservoirs is in shorter supply.

The snowpack reflects the rays of the sun, using up more of the sun's energy.

Meltwater used for ranching and mining is nearly gone by late summer.

The snowpack becomes a dusty, darker color, absorbing more of the sun's heat.

2. The best alternative headline for this article would be __________.
Melting Snowpack Disturbs Colorado Desert Crust

Wind-blown Dust a Problem for Ranchers and Miners

Melting Snowpack Dampens Colorado Dust Storms

Wind-blown Dust Drying Up Mountain Meltwater

3. Which is the closest synonym for the word curtail?
Reprove

Ravage

Restrain

Retrieve

4. Which of these is an accurate comparison between dust-laden snow and clean snow?
Dust-laden snow disturbs the desert crust, while clean snow creates abundant meltwater.

Dust-laden snow absorbs more of the sun's energy, while clean snow reflects most of the sun's energy.

Dust-laden snow regulates the earth's temperature, while clean snow raises the earth's temperature.

Dust-laden snow reflects more of the sun's energy, while clean snow absorbs most of the sun's energy.

5. The article states:
By the summer's hottest months they are growing worried about the dwindling water supply.
Which would be the closest antonym for the word dwindling?
Escalating

Denouncing

Canvassing

Adhering

6. The news article says all of the following except __________.
Seasonal climate change causes the mountain snowpack to melt at a normal rate.

Colorado is famous among skiers and snowboarders for its clean and deep snows.

Energy exploration in the Colorado Plateau is blowing dust onto the Alps.

Human activity over many years is contributing to a global dust problem.

7. What of these happened before 2006?
The snowpack on the Colorado Mountains melted 150 days sooner than in dust-free years.

The number of dust storms from Arizona and New Mexico were double what they were in 2006.

The snowpack on the Colorado Plateau lasted 150 days longer than it did in dust-free years.
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The number of dust storms from Arizona and New Mexico were half what they were in 2006.

8. In the last paragraph, the author presents examples of how dust secretions have increased in areas other than
Colorado in order to __________.
Illustrate that dust from ranching and mining is traveling to other parts of the world

Illustrate that the problems resulting from dust-laden snow are a global concern

Emphasize that sheep grazing in Patagonia is causing more problems than mining in Colorado

Emphasize that other countries are dealing with much more serious windstorms than Colorado