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Climate: What if Arctic sea ice doesn’t form in winter?


Arctic sea ice is on a downward spiral. Visit this NASA Earth Observatory website for information on this image.

New models look at year-round ice-free conditions to find parallels with Pliocene epoch

By Summit Voice

FRISCO — As atmospheric concentrations of carbon dioxide start to hover around 400 parts per million, climate scientists have been looking back about 3 to 5 million years, to the Pliocene Epoch — the last time heat-trapping greenhouse gases were at a similar level.

But temperatures during the Pliocene were about 3.5 to 9 degrees Fahrenheit warmer than today and the sea level was 65 to 80 feet higher. Until now, scientists have assumed that there’s a time lag between atmospheric CO2 levels and the subsequent temperature increases that melt ice and drive ocean levels up. Continue reading

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Climate: NASA to probe forest and forest fire emissions


New climate research could help fine-tune global warming models. Photo courtesy NASA.

Satellites and planes to scour atmosphere from top to bottom

By Summit Voice

FRISCO — Since clouds and pollution high in the atmosphere are still somewhat of a global warming wild card, scientists have been trying to refine their understanding of how those factors affect the climate.

Better data could help refine climate models used to project how much temperatures will increase the next few decades, and a new NASA research project starting in early August could deliver some of that information.

Satellite sensors will probe from above, while planes with instruments on board will fly near the edge of space and at lower elevations simultaneously to provide a multi-dimensional look at how air pollution and natural emissions, which are pushed high into the atmosphere by large storms, affect atmospheric composition and climate. Continue reading

Colorado scientists quantify increased dust pollution

Tracking calcium deposits shows big increase in dust deposition in the past couple of decades


Desert dust taints the snow at Loveland Pass, Colorado, speeding snowmelt and sometimes contributing to avalanche hazards. Bob Berwyn photo.


NASA satellite images can help track dust storms.

By Bob Berwyn

FRISCO — Significant dust storms the past few years have had a big impact on the timing of snowmelt in the Colorado Rockies, but scientists haven’t been able to say for certain if those events are becoming more frequent.

Now, a new study from the University of Colorado Boulder shows that the amount of dust deposition has increased, at least during the 17-year span covered by the researchers, who tracked calcium deposits to reach their conclusions. Calcium dissolved in precipitation has long been measured by the National Atmospheric Deposition Program as a way assess acid rain.

The scientists reviewed calcium deposition data from 175 NADP sites across the United States between 1994 and 2010, measuring increases in calcium deposition increased at 116 locations. The sites with the greatest increases were clustered in the Northwest, the Midwest and the Intermountain West, with Colorado, Wyoming and Utah seeing especially large increases. Continue reading

The Grand Canyon gets a new birthday

New geologic technique suggests the Grand Canyon is 60 million years older than previously thought


There’s no better place to contemplate Earth’s geological mysteries than the rim of the Grand Canyon, which may be quite a bit older than scientists had thought. Photo by Leigh Wadden.

By Summit Voice

SUMMIT COUNTY — When you stand on the edge of the Grand Canyon, it becomes a little easier to visualize the almost unimaginably powerful forces that give Earth the shape we know today — and also to get a sense of how long some of those processes have been at work.

New research led by CU-Boulder assistant professor Rebecca Flowers suggests that the Grand Canyon may be 60 million years older than previously thought. An analysis of mineral grains from the bottom of the western Grand Canyon indicates it was largely carved out by about 70 million years ago — a time when dinosaurs were around and may have even peeked over the rim.

The scientists used a dating method that exploits the radioactive decay of uranium and thorium atoms to helium atoms in a phosphate mineral known as apatite, said Flowers, a faculty member in CU-Boulder’s geological sciences department. The technique may help researchers unravel other geological mysteries. Continue reading

Forests: CU study traces evolution of pine beetle outbreak

Beetle-killed lodgepole pines dominate the landscape in many parts of Summit County.

2002 drought played key role in accelerating insect invasion

By Summit Voice

SUMMIT COUNTY — Drought conditions in the early 2000s helped pine beetle populations surge to unprecedented levels, according to a new University of Colorado study that charts the evolution of the current pine beetle epidemic in the southern Rocky Mountains.

But even when the drought eased, the outbreak continued to gain ground, spreading into wetter and higher elevations and into less susceptible tree stands — those with smaller diameter lodgepoles sharing space with other tree species, according to CU-Boulder doctoral student Teresa Chapman.

“In recent years some researchers have thought the pine beetle outbreak in the southern Rocky Mountains might have started in one place and spread from there,” said Chapman. “What we found was that the mountain pine beetle outbreak originated in many locations. The idea that the outbreak spread from multiple places, then coalesced and continued spreading, really highlights the importance of the broad-scale drivers of the pine beetle epidemic like climate and drought.” Continue reading

CU study eyes water, climate and land-use tipping points

Reservoirs were left high and dry by this summer’s drought.

National Science Foundation funding enables detailed research on trans-basin water diversions

By Summit Voice

SUMMIT COUNTY — As some West Slope aquatic ecosystems teeter on the brink of collapse due to water diversions, a group of CU researchers will use a $1.4 million grant from the National Science Foundation to try and pinpoint tipping points, beyond which systems may be pushed into an unsustainable state.

The research will examine how changes in land use, forest management and climate may affect trans-basin water diversions in Colorado and other semi-arid regions in the western United States, finding thresholds that could compromise the sustainability of the policies and procedures that dictate the timing and quality of water diverted from Colorado’s West Slope to the Front Range.

The grant, part of the National Science Foundation-U.S. Department of Agriculture Water Sustainability Climate Program, was awarded to assistant professor Noah Molotch of the geography department, who singled out Summit County as one focus area for the study. Continue reading

New CU study shows that nitrogen compounds from cars, power plants and agriculture threaten alpine ecosystems

Part of Colorado’s alpine landscape may face irreversible changes from nitrogen pollution. Photo by Bob Berwyn.

Acidification of soil is nearly irreversible

By Summit Voice

SUMMIT COUNTY — Nitrogen compounds from power plants, auto emissions and agriculture is starting to change the alpine vegetation in Rocky Mountain National Park in “subtle but important” ways, according to a University of Colorado Boulder study conducted at the school’s Mountain Research Station.

In other regions of the world, higher amounts of nitrogen pollutants correlate with decreased biodiversity, acidified soils and dead stream organisms like trout, said research station director Professor William Bowman.

“There is evidence that indicates once these changes occur, they can be difficult if not impossible to reverse. It is best to recognize these early stages before the more harmful later stages happen.” Continue reading

Global warming: Long-term research by CU Boulder team suggests Colorado’s alpine tundra and forests are in trouble

Snow-dependent ecosystems highly sensitive to climate change

Some research suggests that Colorado's conifer forests will have a hard time rebounding from beetle-kill impacts due to climate change.

By Summit Voice

SUMMIT COUNTY — It might not come as a total surprise that ecosystems dependent on seasonal snow and ice are among the most sensitive to climate change — but some of the impacts may be unexpected.

For example, researchers with the University of Colorado Boulder found that one of their high altitude climate stations has recorded a trend toward wetter and cooler conditions in recent years, while another site nearby, but lower in elevation, has become significantly warmer and drier.

“In the past we tried to look at pristine ecosystems, but those are essentially gone. So we’ve come up with an approach that integrates human activities with our ecological research,” said CU-Boulder Professor Mark Williams, the principal investigator on CU’s Niwot Ridge Long-term ecological research site.

Key measurements at the Niwot Ridge site — which has climate records going back more than 60 years thanks to pioneering work by CU biology Professor John Marr in the 1950s — are temperature and precipitation logs from two stations, one at 12,700 feet in elevation and a second at 10,000 feet. Continue reading

CU researchers to help assess Himalayan water supplies

Future climate change impacts to region not clear yet

The High Asia mountains funnel water into such major river basins as the Ganges, Brahmaputra, Indus, Amu Darya and Syr Darya.
—Credit: James Schweithelm, USAID

By Summit Voice

SUMMIT COUNTY —A meltdown of Himalayan glaciers may not be imminent, but there is a lot of concern about how a changing climate may affect water resources in one of the world’s most densely population regions.

Most of the Indian subcontinent relies on water stored in mountain snowpack and glaciers, yet there is not much in the way of reliable baseline data, so a University of Colorado Boulder team is partnering with the United States Agency for International Development to assess snow and glacier contributions to those water resources.

There is a lot of misinformation in the public arena regarding glaciers, including reports that glaciers in the Himalaya are receding faster than anywhere else in the world and, if this rapid melting continues, rivers are on track to first flood and then dry up, according to Richard Armstrong, a scientist with the National Snow and Ice Data Center.

“Those reports simply are not true,” said Armstrong, who is partnering with Mark Williams of the Institute of Arctic and Alpine Research at CU on the study. Continue reading

Global warming: CU-led study pinpoints Earth’s ice loss

Arctic sea ice extent is below average in early February, according to the National Snow and Ice Data Center.

New data to help project sea level rise

By Summit Voice

Earth’s glaciers and ice caps outside of the regions of Greenland and Antarctica are shedding about 150 billion tons of ice annually, according to a new study led by the University of Colorado Boulder.

The total mass ice loss from Greenland, Antarctica and all Earth’s glaciers and ice caps between 2003 to 2010 was 1,000 cubic miles, about eight times the water volume of Lake Erie.

“The total amount of ice lost to Earth’s oceans from 2003 to 2010 would cover the entire United States in about 1 and one-half feet of water,” said CU-Boulder physics Professor John Wahr, who helped lead the study. Continue reading


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