Study assesses likelihood of Arctic ozone hole

This year's ozone hole over Antarctica was the second-smallest in 20 years, according to NASA.

Last year’s ozone hole over Antarctica was the second-smallest in 20 years, according to NASA.

CFC ban showing signs of success

Staff Report

FRISCO — Scientists say it’s unlikely that the Arctic will see ozone depletion on the scale of the Antarctic ozone hole, thanks mainly to international efforts to limit ozone-killing chemicals.

“While there is certainly some depletion of Arctic ozone, the extremes of Antarctica so far are very different from what we find in the Arctic, even in the coldest years,” said MIT atmospheric scientists Susan Solomon.

“It’s really a success story of science and policy, where the right things were done just in time to avoid broader environmental damage,” said Solomon, who made some of the first measurements in Antarctica that pointed toward CFCs as the primary cause of the ozone hole. Continue reading

Environment: Is the Amazon rainforest near a tipping point?

A NASA photo taken from the International Space Station shows sunlight glinting off the Amazon River.

A NASA photo taken from the International Space Station shows sunlight glinting off the Amazon River.

Drought the main driver of destructive fires

By Staff Report

FRISCO — Longer droughts, land-use changes and wildfires may  be pushing parts of the Amazon rainforest toward an ecological tipping point, a team of scientists said after analyzing the effects of fire in a series of study plots.

The changes may abruptly increase tree mortality and change vegetation over large areas, the researchers said, pointing out that current Amazon forest models don’t include the impacts of wildfires. As a result, projections of future forest health tend to underestimate the amount of tree death and overestimate overall forest health, said Dr. Michael Coe, of the Woods Hole Research Center. Continue reading

Colorado wetlands to regain federal protection

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High alpine wetlands that aren’t directly connected with larger rivers will regain more protection under a proposed new federal rule. bberwyn photo.

New rule aims to clear up regulatory limbo for seasonal streams and isolated wetlands

By Bob Berwyn

FRISCO — A proposed federal rule would restore protection to hundreds of Colorado streams and big swaths of wetlands, including beloved alpine creeks and the sandy washes of the Front Range that only hold water seasonally.

The seasonal streams and disconnected wetlands long were covered under the Clean Water Act, but a pair of complex U.S. Supreme Court rulings in 2001 and 2006 opened some loopholes the regulations. At the least, the legal limbo caused headaches for scientists and regulators trying to assess impacts of housing developments and new roads. In some cases, they weren’t sure if they even had authority to regulate filling or draining of some wetlands. Continue reading

Climate: ‘We need to move away from business as usual’

Curbing global warming will require big cuts in greenhouse gases

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March 2014 temperatures were above average across most of the globe.

By Summit Voice

FRISCO —Greenhouse gas emissions continue to climb despite international attempts to curb heat-trapping gases, the Intergovernmental Panel on Climate Change said in its latest climate report.

Issued Sunday in Berlin, the report shows that greenhouse gas emissions grew more quickly between 2000 and 2010 than in each of the three previous decades. Only with significant institutional, social and technological changes will humankind be able to meet its stated target of limiting warming to two degrees Celsius, the scientists wrote. Continue reading

Study: Little chance that global warming is natural

Statistical analysis of temperature data affirms climate models

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Warmer than average temperatures prevailed across most of the globe in March 2014.

Staff Report

FRISCO — A new statistical analysis of temperature records dating back to 1500 suggests it’s more than 99 percent certain that the past century of global warming is caused by the emission of heat-trapping, industrial-age greenhouse gases. The study was published online April 6 in the journal Climate Dynamics.

In a press release, the McGill University researchers said the study doesn’t use complex computer models to estimate the effects of greenhouse-gas emissions. Instead, it examines historical data to assess the competing hypothesis that warming over the past century is due to natural long-term variations in temperature. The results all but rule out  the possibility that global warming in the industrial era is just a natural fluctuation in the earth’s climate. Continue reading

NASA: Noctilucent clouds on the increase

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NASA’s Aeronomy of Ice in the Mesosphere, or AIM, mission captured this image of noctilucent clouds over the poles in 2010. By compiling data from several missions at once, researchers have now created a record of the clouds at lower latitudes as well. Image Credit: NASA/AIM

FRISCO — If you’ve been seeing more strange clouds that glow at night, it’s not your imagination. The occurrence of those types of clouds increased between 2002 and 2011, according to a new study analyzing satellite data from a variety of sources. Combining the information and using computer models, the NASA scientists found the greatest increase in  areas between 40 and 50 degrees north latitude, a region which covers the northern third of the United Sates and the lowest parts of Canada. The research was published online in the Journal of Geophysical Research: Atmospheres on March 18, 2014.

These changes correlate to a decrease in temperature at the peak height where noctilucent clouds exist in the atmosphere. Temperatures at this height do not match temperatures at lower levels – indeed, the coldest place in the atmosphere is at this height during summertime over the poles – but a change there certainly does raise questions about change in the overall climate system.

“Noctilucent clouds occur at altitudes of 50 miles above the surface — so high that they can reflect light from the sun back down to Earth,” said James Russell, an atmospheric and planetary scientist at Hampton University in Hampton, Va., and first author on the paper. “AIM and other research has shown that in order for the clouds to form, three things are needed:  very cold temperatures, water vapor and meteoric dust. The meteoric dust provides sites that the water vapor can cling to until the cold temperatures cause water ice to form.”

To study long-term changes in noctilucent clouds, Russell and his colleagues used historical temperature and water vapor records and a validated model to translate this data into information on the presence of the clouds. They used temperature data from 2002 to 2011 from NASA’s Thermosphere Ionosphere Mesosphere Energetics and Dynamics, or TIMED, mission and water vapor data from NASA’s Aura mission from 2005 to 2011. They used a model previously developed by Mark Hervig, a co-author on the paper at GATS, Inc., in Driggs, Idaho.

The team tested the model by comparing its output to observations from the Osiris instrument on the Swedish Odin satellite, which launched in 2001, and the SHIMMER instrument on the U.S. Department of Defense STPSat-1 mission, both of which observed low level noctilucent clouds over various time periods during their flights. The output correlated extremely well to the actual observations, giving the team confidence in their model.

Russell and his team will research further to determine if the noctilucent cloud frequency increase and accompanying temperature decrease over the 10 years could be due to a reduction in the sun’s energy and heat, which naturally occurred as the solar output went from solar maximum in 2002 to solar minimum in 2009.

“As the sun goes to solar minimum, the solar heating of the atmosphere decreases, and a cooling trend would be expected,” said Russell.

 

Oyster farming could clean up Potomac River

New NOAA-USGS study evaluates aquaculture cleanup potential

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Oysters could help clear the water in the Potomac River estuary.

Staff Report

FRISCO — Degraded water quality in the Potomac River estuary could be improved with intensive cultivation of oysters according to a new NOAA and U.S. Geological Survey study published in the journal Aquatic Geochemistry.

As filter feeders, oysters could remove all of the nitrogen currently polluting the river if 40 percent of its river bed were used for shellfish cultivation. The researchers determined that a combination of aquaculture and restored oyster reefs may provide even larger overall ecosystem benefits. Oysters can clean an enormous volume of water of algae which can cause poor water quality, leading to unwanted algae blooms and dead zones. Continue reading

California condors still dying of lead poisoning

A tagged California condor in flight.

A tagged California condor in flight.

New study suggests that spent lead ammunition could make it impossible to recover the species

Staff Report

FRISCO — Accidental ingestion of spent lead ammunition is killing endangered California condors at a rate that may prevent the birds from establishing self-sustaining populations.

The condors were among the first animals to be protected under the Endangered Species Act. By 1966, the population had dropped to just a handful of birds, but a massive collaborative conservation effort helped the population grow to more than 400 individuals.

But those gains may be at risk, according to San Diego Zoo conservation biologists.

“After reviewing nearly 20 years of our mortality data on the free-ranging birds, it became clear that lead poisoning is the primary problem for the birds in the wild,” said Bruce Rideout, director of the wildlife disease laboratories for San Diego Zoo Global.

“And this is not just a problem for California condors. We can view them as an indicator species, warning us about the hazards of widespread lead contamination in the environment.” said Bruce Rideout, director of the wildlife disease laboratories for San Diego Zoo Global.

The recent study of lead impacts was done with researchers from the Wildlife Health Center at the School of Veterinary Medicine, University of California at Davis. The findings are published in the  January edition of the journal EcoHealth.

 

Climate: Arctic sea ice peaks for the year

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Arctic sea ice extent is declining at 2.6 percent each decade.

March surge boosts extent late in the season

Staff Report

FRISCO — Arctic sea ice grew to its maximum extent for the year on March 21, reaching 5.70 million square miles. According to the National Snow and Ice Data Center, it was the fifth-lowest maximum extent in the satellite monitoring era, starting in 1978. The lowest maximum extent occurred in 2011, at 5.65 million square miles.

The average date for maximum sea ice extent is March 9, just a couple of weeks after the spring equinox, but the date varies from year to year. The latest maximum on record was in 2011, when sea ice extent expanded through March 31. Through 2014, the linear rate of decline for March ice extent is 2.6 percent per decade relative to the 1981 to 2010 average. Continue reading

Climate: New study projects major habitat losses for birds, reptiles in Southwest

Gray jay in Summit County Colorado

A gray jay searches for bugs in a stand of lodgepole pines near Frisco, Colorado.

A few bird species may gain some ground

By Summit Voice

FRISCO — Reptile species like the iconic chuckwalla will probably experience significant habitat loss as global temperatures climb during the next few decades, scientists said this week in a new study projecting climate change impacts to southwestern birds and reptiles.

The study was done by scientists with the U.S. Geological Survey,  University of New Mexico, and Northern Arizona University. Overall, the findings suggests many reptile species will lose ground as conditions get warmer and more dry.  Continue reading

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