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 “Climate: What if Arctic sea ice doesn’t form in winter?”→
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 “Climate: NASA to probe forest and forest fire emissions”→
Tracking calcium deposits shows big increase in dust deposition in the past couple of decades
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 “Colorado scientists quantify increased dust pollution”→
New geologic technique suggests the Grand Canyon is 60 million years older than previously thought
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.
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 “Forests: CU study traces evolution of pine beetle outbreak”→
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.
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.