Fires, Floods, Snow extremes
Breaking news about Wild Land Fires & Floods and snow storms in the Boulder, Colorado area.
CU study: Melting glaciers are largely responsible for sea level rise
0May 16, 2013
While 99 percent of Earth’s land ice is locked up in the Greenland and Antarctic ice sheets, the remaining ice in the world’s glaciers contributed just as much to sea rise as the two ice sheets combined from 2003 to 2009, says a new study led by Clark University and involving the University Colorado Boulder.
The new research found that all glacial regions lost mass from 2003 to 2009, with the biggest ice losses occurring in Arctic Canada, Alaska, coastal Greenland, the southern Andes and the Himalayas. The glaciers outside of the Greenland and Antarctic sheets lost an average of roughly 260 billion metric tons of ice annually during the study period, causing the oceans to rise 0.03 inches, or about 0.7 millimeters per year.
The study compared traditional ground measurements to satellite data from NASA’s Ice, Cloud and Land Elevation Satellite, or ICESat, and the Gravity Recovery and Climate Experiment, or GRACE, missions to estimate ice loss for glaciers in all regions of the planet.
“For the first time, we’ve been able to very precisely constrain how much these glaciers as a whole are contributing to sea rise,” said geography Assistant Professor Alex Gardner of Clark University in Worcester, Mass., lead study author. “These smaller ice bodies are currently losing about as much mass as the ice sheets.”
A paper on the subject is being published in the May 17 issue of the journal Science.
“Because the global glacier ice mass is relatively small in comparison with the huge ice sheets covering Greenland and Antarctica, people tend to not worry about it,” said CU-Boulder Professor Tad Pfeffer, a study co-author. “But it’s like a little bucket with a huge hole in the bottom: it may not last for very long, just a century or two, but while there’s ice in those glaciers, it’s a major contributor to sea level rise,” said Pfeffer, a glaciologist at CU-Boulder’s Institute of Arctic and Alpine Research
ICESat, which ceased operations in 2009, measured glacier changes using laser altimetry, which bounces laser pulses off the ice surface to determine changes in the height of ice cover. The GRACE satellite system, still operational, detects variations in Earth’s gravity field resulting from changes in the planet’s mass distribution, including ice displacements.
GRACE does not have a fine enough resolution and ICESat does not have sufficient sampling density to study small glaciers, but mass change estimates by the two satellite systems for large glaciated regions agree well, the scientists concluded.
“Because the two satellite techniques, ICESat and GRACE, are subject to completely different types of errors, the fact that their results are in such good agreement gives us increased confidence in those results,” said CU-Boulder physics Professor John Wahr, a study co-author and fellow at the university’s Cooperative Institute for Research in Environmental Sciences.
Ground-based estimates of glacier mass changes include measurements along a line from a glacier’s summit to its edge, which are extrapolated over a glacier’s entire area. Such measurements, while fairly accurate for individual glaciers, tend to cause scientists to overestimate ice loss when extrapolated over larger regions, including individual mountain ranges, according to the team.
Current estimates predict if all the glaciers in the world were to melt, they would raise sea level by about two feet. In contrast, an entire Greenland ice sheet melt would raise sea levels by about 20 feet, while if Antarctica lost its ice cover, sea levels would rise nearly 200 feet.
The study involved 16 researchers from 10 countries. In addition to Clark University and CU-Boulder, major research contributions came from the University of Michigan, the Scripps Institution of Oceanography in San Diego, Trent University in Ontario, Canada, and the University of Alaska Fairbanks.
Built by Ball Aerospace & Technologies in Boulder, NASA’s ICESat satellite was successfully operated from the CU-Boulder campus by a team made up primarily of undergraduates from its launch in 2003 to its demise in 2009 when the science payload failed. The students participated in the unusual decommissioning of a functioning satellite in 2010, bringing the craft into Earth re-entry to burn up. ICESat’s successor, ICESat-2, is slated for launch in 2016 by NASA.
-CU media release-
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CU study: 66 million years ago, an asteroid turned Earth into a crispy critter
0March 27, 2013
A new look at conditions after a Manhattan-sized asteroid slammed into a region of Mexico in the dinosaur days indicates the event could have triggered a global firestorm that would have burned every twig, bush and tree on Earth and led to the extinction of 80 percent of all Earth’s species, says a new University of Colorado Boulder study.
Led by Douglas Robertson of the Cooperative Institute for Research in Environmental Sciences, or CIRES, the team used models that show the collision would have vaporized huge amounts of rock that were then blown high above Earth’s atmosphere. The re-entering ejected material would have heated the upper atmosphere enough to glow red for several hours at roughly 2,700 degrees Fahrenheit — about the temperature of an oven broiler element — killing every living thing not sheltered underground or underwater.
An artist’s rendition of the asteroid air strike 66 million years ago
The CU-led team developed an alternate explanation for the fact that there is little charcoal found at the Cretaceous-Paleogene, or K-Pg, boundary some 66 million years ago when the asteroid struck Earth and the cataclysmic fires are believed to have occurred. The CU researchers found that similar studies had corrected their data for changing sedimentation rates. When the charcoal data were corrected for the same changing sedimentation rates they show an excess of charcoal, not a deficiency, Robertson said.
“Our data show the conditions back then are consistent with widespread fires across the planet,” said Robertson, a research scientist at CIRES, which is a joint institute of CU-Boulder and the National Oceanic and Atmospheric Administration. “Those conditions resulted in 100 percent extinction rates for about 80 percent of all life on Earth.”
A paper on the subject was published online this week in the Journal of Geophysical Research-Biogeosciences, a publication of the American Geophysical Union. Co-authors on the study include CIRES Interim Director William Lewis, CU Professor Brian Toon of the atmospheric and oceanic sciences department and the Laboratory for Atmospheric and Space Physics and Peter Sheehan of the Milwaukee Public Museum in Wisconsin.
Geological evidence indicates the asteroid collided with Earth about 66 million years ago and carved the Chicxulub crater in Mexico’s Yucatan Peninsula that is more than 110 miles in diameter. In 2010, experts from 33 institutions worldwide issued a report that concluded the impact at Chicxulub triggered mass extinctions, including dinosaurs, at the K-Pg boundary.
The conditions leading to the global firestorm were set up by the vaporization of rock following the impact, which condensed into sand-grain-sized spheres as they rose above the atmosphere. As the ejected material re-entered Earth’s atmosphere, it dumped enough heat in the upper atmosphere to trigger an infrared “heat pulse” so hot it caused the sky to glow red for several hours, even though part of the radiation was blocked from Earth by the falling material, he said.
But there was enough infrared radiation from the upper atmosphere that reached Earth’s surface to create searing conditions that likely ignited tinder, including dead leaves and pine needles. If a person was on Earth back then, it would have been like sitting in a broiler oven for two or three hours, said Robertson.
The amount of energy created by the infrared radiation the day of the asteroid-Earth collision is mind-boggling, said Robertson. “It’s likely that the total amount of infrared heat was equal to a 1 megaton bomb exploding every four miles over the entire Earth.”
A 1-megaton hydrogen bomb has about the same explosive power as 80 Hiroshima-type nuclear bombs, he said. The asteroid-Earth collision is thought to have generated about 100 million megatons of energy, said Robertson.
Some researchers have suggested that a layer of soot found at the K-Pg boundary layer roughly 66 million years ago was created by the impact itself. But Robertson and his colleagues calculated that the amount of soot was too high to have been created during the massive impact event and was consistent with the amount that would be expected from global fires.
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Boulder County: Emergency warning sirens to be tested beginning April 1
0March 26, 2013
Boulder County, Colo. – Boulder County and the City of Boulder will begin audible testing of the countywide emergency sirens at 10 a.m. on Monday, April 1. The test is the first of the annual season of monthly emergency audible siren tests, which take place on the first Monday of each month from April through August.
The audible siren tests will occur twice on each testing day, at 10 a.m. and 7 p.m., on April 1, May 6, June 3,July 1 and Aug. 5.
Siren tests ensure that all systems and procedures are working properly during the season of peak flood danger. The tests also promote public awareness of the warning sirens located throughout Boulder County.
Louisville, Superior and Jamestown sirens will only participate in the first audible test of the season on April 1. After this test, residents in these communities will not hear the sirens unless there is an emergency.
Should Boulder County experience severe weather during one of the planned audible tests, the siren tests for that day may be cancelled. For updated information, visit www.BoulderOEM.com.
Residents are encouraged to review their own emergency preparedness plans and discuss what they would do in the event of a flash flood or other emergency. For more information about personal preparedness, visitwww.readycolorado.com.
About the countywide alert system
Used to alert residents to potential danger from a flood or other immediate threat, there are 25 outdoor warning sirens in place across Boulder County, including in Boulder, Erie, Jamestown, Lafayette, Louisville, Lyons, Marshall, Eldorado Springs, Superior and the University of Colorado at Boulder.
All Boulder County sirens undergo weekly tests throughout the year, using a software program that performs a “silent” test.
For more information, visit www.BoulderOEM.com.
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Community Forestry Sort Yards to open in May
0March 20, 2013
“Spring is a great time of year to get out on your land and begin preparing your property for wildfires.”
Boulder County, Colo. – The Boulder County Forest Health Initiative is pleased to announce the Community Forestry Sort Yard operating schedule for 2013. Two sort yard locations are open each summer to provide residents a free of charge location to dispose of logs and slash cut from their land.
The sort yards do not accept yard clippings, raked up pine needles, root balls, construction materials, dirt, furniture, household trash or wood with metal in it. Sort yard staff will refuse loads that contain unacceptable items.
Allenspark/Meeker Park Sort Yard
- Spring hours: Fridays and Saturdays from 9 a.m. to 5 p.m. May 24th thru June 15th
- Summer/Fall hours: Tuesday thru Saturday 9 a.m. to 5 p.m. July 30th thru Oct. 19th
Nederland Area Sort Yard
- Spring hours: Tuesday thru Saturday from 9 a.m. to 5 p.m. May 1st thru July 6th (closed July 4th)
- Summer/Fall hours: Fridays and Saturdays from 9 a.m. to 5 p.m. Sept. 20th thru Oct. 12th (these dates are tentative)
The Community Forestry Sort Yards may have additional closures during the open season due to weather, staff training or other administrative requirements. To check the operational status of a sort yard please call 303-678-6368.
Boulder County encourages all of its residents to be good stewards of their backyard forest and to implement effective wildfire mitigation on their land.
“The spring is a great time of year to get out on your land and begin preparing your property for wildfires,” said Ryan Ludlow outreach forester with the county’s Land Use Department. “Simple actions like picking up downed branches, raking away all pine needles within 5 feet of your structures, cutting tall dead grass and moving leftover winter firewood piles off of porches and placing them at least 30 feet away from the home can really help improve the chances of your home surviving the next wildfire.”
If you want to learn more about how to implement effective wildfire mitigation on your land join us at the Nederland Community Center on May 11 for a half day workshop focused on “Firewise Landscaping.” Learn how to transform your home’s perimeter into an area that you can not only use, but also looks good and helps protect your home from wildfire.
For more information about the sort yard program or how to implement proactive wildfire mitigation on your land, contact Ryan Ludlow, Boulder County Forest Health Initiative’s outreach forester, at 720-564-2641 orrludlow@bouldercounty.org.
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Deputy, police officer and neighbor make a harrowing rescue
0February 11, 2013
On Sunday, February 9, 2013 at 11:28 pm, the Boulder County Regional Communications received a report of an explosion and fire at 5479 Jay Road, just outside the City of Boulder. At 11:31 pm, Boulder County Sheriff’s Deputy Jeff George was first on scene, to find the home on fire. A neighbor advised Deputy George that an elderly woman lived alone in the residence. Deputy George forced entry into the home and found 83 year old, Marvyl Holder on the floor in her bedroom.
The neighbor, John Walpole, followed Deputy George into the residence and assisted in removing Marvyl out of the residence. Boulder Police Officer Ed Burke, the second responder, assisted George in carrying Marvyl away from the residence just moments before a second explosion in the residence.
Fire personnel from Boulder Rural Fire, City of Boulder Fire, Rocky Mountain Fire, Lafayette Fire and Mountain View Fire responded and extinguished the fire. The Boulder County Multi-Agency Fire Investigation Team (MAFIT) will investigate first thing this morning, but preliminary indications are pointing towards a gas leak. The home is considered to be a total loss.
Marvyl Holder and Deputy Jeff George were both evaluated by paramedics from AMR Ambulance and found to be alright, suffering from only minor smoke inhalation.
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CU researchers say deep ice cores show past Greenland warm period may be ‘road map’ for continued warming of planet
0January 23, 2013
A new study by an international team of scientists analyzing ice cores from the Greenland ice sheet going back in time more than 100,000 years indicates the last interglacial period may be a good analog for where the planet is headed in terms of increasing greenhouse gases and rising temperatures.
The new results from the NEEM deep ice core drilling project led by the University of Copenhagen and involving the University of Colorado Boulder show that between 130,000 and 115,000 years ago during the Eemian interglacial period, the climate in north Greenland rose to about 14 degrees Fahrenheit warmer than today. Despite the strong warming signal during the Eemian — a period when the seas were roughly 15 to 25 feet higher than today — the surface of the north Greenland ice sheet near the NEEM facility was only a few hundred yards lower than it is today, an indication to scientists it contributed less than half of the total sea rise at the time.
Greenland ice burg
The NEEM project involves 300 scientists and students from 14 countries and is led by Professor Dorthe Dahl-Jensen, director of the University of Copenhagen’s Centre of Ice and Climate. CU-Boulder geological sciences professor and ice core expert Jim White is the lead U.S. investigator on the project. The National Science Foundation’s Division of Polar Programs funded the U.S. portion of the effort.
The new Nature findings showed that about 128,000 years ago, the surface elevation of ice near the NEEM site was more than 650 feet higher than present but the ice was starting to thin by about 2 inches per year. Between about 122,000 and 115,000 years ago, Greenland’s surface elevation remained stable at roughly 425 feet below the present level. Calculations indicate Greenland’s ice sheet volume was reduced by no more than 25 percent between 128,000 years ago and 122,000 years ago, said White.
A paper on the subject was published in the Jan. 24 issue of Nature.
“When we calculated how much ice melt from Greenland was contributing to global sea rise in the Eemian, we knew a large part of the sea rise back then must have come from Antarctica,” said White, director of CU-Boulder’s Institute of Arctic and Alpine Research. “A lot of us had been leaning in that direction for some time, but we now have evidence that confirms that the West Antarctic ice sheet was a dynamic and crucial player in global sea rise during the last interglacial period.”
Dahl-Jensen said the loss of ice mass on the Greenland ice sheet in the early part of the Eemian was likely similar to changes seen there by climate scientists in the past 10 years. Other studies have shown the temperatures above Greenland have been rising five times faster than the average global temperatures in recent years, and that Greenland has been losing more than 200 million tons of ice annually since 2003. The Greenland ice loss study was led by former CU-Boulder scientist Isabella Velicogna, who is currently a faculty member at the University of California, Irvine.
The intense melt in the vicinity of NEEM during the warm Eemian period was seen in the ice cores as layers of re-frozen meltwater. Such melt events during the last glacial period were rare by comparison, showing that the surface temperatures at the NEEM site were in a cold, nearly constant state back then. But on July 12, 2012, satellite images from NASA indicated 97 percent of Greenland’s ice sheet surface had thawed as a result of warming temperatures.
“We were quite shocked by the warm surface temperatures observed at the NEEM ice camp in July 2012,” said Dahl-Jensen. “It was raining at the top of the Greenland ice sheet, and just as during the Eemian period, meltwater formed subsurface ice layers. While this was an extreme event, the present warming over Greenland makes surface melt more likely, and the predicted warming over Greenland in the next 50-100 years will very likely be so strong that we will potentially have Eemian-like climate conditions.”
The Greenland ice core layers — formed over millennia by compressed snow — are being studied in detail using a suite of measurements, including stable water isotope analysis that reveals information about temperature and greenhouse gas levels and moisture changes back in time. Lasers are used to measure the water stable isotopes and atmospheric gas bubbles trapped in the ice cores to better understand past variations in climate on an annual basis — similar in some ways to a tree-ring record.
The results from the Nature study provide scientists with a “road map” of sorts to show where a warming Earth is headed in the future, said White. Of the nine hottest years on Earth on record, eight have come since the year 2000. In 2007 the Intergovernmental Panel on Climate Change concluded that temperatures on Earth could climb by as much as 11 degrees F by 2100.
Greenland glacier grooves
Increasing amounts of carbon dioxide in the atmosphere from sources like vehicle exhaust and industrial pollution — which have risen from about 280 parts per million at the onset of the Industrial Revolution to 391 parts per million today — are helping to raise temperatures on Earth, with no end in sight, said White.
“Unfortunately, we have reached a point where there is so much carbon dioxide in the atmosphere it’s going to be difficult for us to further limit our impact on the planet,” White said. “Our kids and grandkids are definitely going to look back and shake their heads at the inaction of this country’s generation. We are burning the lion’s share of oil and natural gas to benefit our lifestyle, and punting the responsibility for it.”
In the past, Earth’s journey into and out of glacial periods is thought to be due in large part to variations in its orbit, tilt and rotation that change the amount of solar energy delivered to the planet, he said. But the anthropogenic warming on Earth today could override such episodic changes, perhaps even staving off an ice age, White said.
While three previous ice cores drilled in Greenland in the last 20 years recovered ice from the Eemian, the deepest layers were compressed and folded, making the data difficult to interpret. Although there was some folding of the lowest ice layers in the NEEM core, sophisticated ice-penetrating radar helped scientists sort out and interpret the individual layers to paint an accurate picture of the warming of Earth’s Northern Hemisphere as it emerged from the previous ice age, White said.
In addition to White, other CU-Boulder co-authors on the NEEM paper include INSTAAR scientist Bruce Vaughn and graduate student Tyler Jones of INSTAAR and CU-Boulder’s Environmental Studies Program.
“It’s a challenge being on the ice sheet, because we are out of our comfort zones and are working long, physical hours in an environment that is extremely cold and where the sun never sets,” Jones said. “Being a member of the research team allowed me to understand the ice core recovery process and the science behind it in terms of learning more about past climates and the implications for future climate change.”
Other nations involved in NEEM include Belgium, Canada, France, Germany, Iceland, Japan, Korea, the Netherlands, Sweden, Switzerland and the United Kingdom. Other U.S. institutions involved in the effort include Oregon State University, Penn State, the University of California, San Diego and Dartmouth College.
For more information on INSTAAR go to http://instaar.colorado.edu/. Additional information, photos and videos on NEEM can be found at http://www.neem.ku.dk.
A video and a slide show on the project will be available on the CU-Boulder news site by clicking on the story headline at http://www.colorado.edu/news.
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CU researchers: Beetle killed trees are better than logging for watersheds
0January 14, 2013
CU-led study shows pine beetle outbreak
buffers watersheds from nitrate pollution
A research team involving several scientists from the University of Colorado Boulder has found an unexpected silver lining in the devastating pine beetle outbreaks ravaging the West: Such events do not harm water quality in adjacent streams as scientists had previously believed.
According to CU-Boulder team member Professor William Lewis, the new study shows that smaller trees and other vegetation that survive pine beetle invasions along waterways increase their uptake of nitrate, a common disturbance-related pollutant. While logging or damaging storms can drive stream nitrate concentrations up by 400 percent for multiple years, the team found no significant increase in the nitrate concentrations following extensive pine beetle tree mortality in a number of Colorado study areas.
Beetle-killed forests do not release nitrogen into the water, according to CU researchers
“We found that the beetles do not disturb watersheds in the same way as logging and severe storms,” said Lewis, interim director of CU’s Cooperative Institute for Research in Environmental Sciences. “They leave behind smaller trees and other understory vegetation, which compensate for the loss of larger pine trees by taking up additional nitrate from the system. Beetle-kill conditions are a good benchmark for the protection of sub-canopy vegetation to preserve water quality during forest management activities.”
A paper on the subject was published in the Jan. 14 issue of the Proceedings of the National Academy of Sciences.
“The U.S. Forest Service and other agencies have established harvesting practices that greatly mitigate damage to forests caused by logging, and they deserve credit for that,” said Lewis. “But this study shows just how important the survival of smaller trees and understory vegetation can be to stream water quality.”
In waterways adjacent to healthy pine forests, concentrations of nitrate is generally far lower than in rivers on the plains in the West like the South Platte, said Lewis. Nitrate pollution is caused by agricultural runoff from populated areas and by permitted discharges of treated effluent from water treatment facilities.
“In Colorado, many watersheds have lost 80 to 90 percent of their tree canopy as a result of the beetle epidemic,” said Lewis, also a faculty member in CU-Boulder’s ecology and evolutionary biology department. “We began to wonder whether the loss of the trees was reducing water quality in the streams. We knew that forestry and water managers were expecting big changes in water quality as a result of the pine beetle outbreak, so we decided to pool our university and federal agency resources in order to come up with an answer.”
Study co-author and CU-Boulder Research Associate James McCutchan of CIRES said the new results should help forest managers develop more effective ways to harvest timber while having the smallest effect possible on downstream ecosystems. “This study shows that at least in some areas, it is possible to remove a large part of the tree biomass from a watershed with a very minimal effect on the stream ecosystem,” he said.
Understory vegetation left intact after beetle outbreaks gains an ecological advantage in terms of survival and growth, since small trees no longer have to compete with large trees and have more access to light, water and nutrients, said McCutchan. Research by study co-author and former CU undergraduate Rachel Ertz showed concentrations of nitrate in the needles of small pines that survived beetle infestations were higher than those in healthy trees outside beetle-killed areas, another indication of how understory vegetation compensates for environmental conditions in beetle kill areas.
The researchers used computer modeling to show that in western forests, such a “compensatory response” provides potent water quality protection against the adverse effects of nitrates only if roughly half of the vegetation survives “overstory” mortality from beetle kill events, which is what occurs normally in such areas, said Lewis.
Other study co-authors included Leigh Cooper, Thomas Detmer and Thomas Veblen from CU-Boulder, John Stednick from Colorado State University, Charles Rhoades from the U.S. Forest Service, Jennifer Briggs and David Clow from the U.S. Geological Survey and Gene Likens of the Cary Institute of Ecosystem Studies in Millbrook, N.Y.
The severe pine beetle epidemic in Colorado and Wyoming forests is part of an unprecedented beetle outbreak that ranges from Mexico to Canada. A November 2012 study by CU-Boulder doctoral student Teresa Chapman showed the 2001-02 drought greatly accelerated the development of the mountain pine beetle epidemic.
The researchers measured stream nitrate concentrations at more than 100 sites in western Colorado containing lodgepole pines with a range of beetle-induced tree damage. The study area included measurements from the Fraser Experimental Forest near Granby, Colo., a 23,000-acre study area established by the USFS in 1937.
The new study was funded by the USFS, the USGS, the National Science Foundation, the National Oceanic and Atmospheric Administration and the National Park Service. CIRES is a joint research institute between CU-Boulder and NOAA.
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Boulder County fire ban rescinded
0December 18, 2012
Tomorrow, December 19, 2012, Sheriff Joe Pelle will rescind the current Fire Ban. The recent precipitation has reduced the fire danger threat by increasing the amount of moisture in the grasses and the other fuels.
Although this current moisture will make a difference lowering our wild fire severity and potential, our local grasses and light flashy fuels will dry out relatively quickly and pose the greatest threat to rapid fire spread. Caution is advised as folks resume using open flame fire for recreational purposes, agricultural maintenance and forest management. Please refrain from burning during windy conditions and have a readily available water supply.
On July 1, 2012, the Boulder County Commissioners passed Boulder County Ordinance 2012-02, developing a permitting system that will encompass public health, local fire protection districts, and Boulder County requirements in a “one stop” online application process. In addition, permits may be obtained by mail or picked up in person at many of the County’s public buildings. The Sheriff’s Office wants to remind citizens that prior to burning (broadcast burns or slash piles) they must obtain a permit. Agricultural burns and campfires are excluded from the permitting process.
To see current fire and shooting restrictions for United States Forest Service properties go to the following website and click on “Alert and Warnings”.
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Sheriff Pelle Orders Fire Ban
0December 3, 2012
Monday, December 03, 2012
On Monday, December 03, 2012 at 12:00 p.m., Sheriff Joe Pelle enacted a fire ban for;
The mountain corridor of Boulder County. The mountain corridor includes all unincorporated areas west of Highway 93 and Highway 36 (North and South Foothills Highways and Broadway Avenue in the City of Boulder) including Rabbit Mountain Open Space.
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CU Boulder study: Alaska’s iconic Columbia Glacier expected to stop retreating in 2020
0November 26, 2012
The wild and dramatic cascade of ice into the ocean from Alaska’s Columbia Glacier, an iconic glacier featured in the documentary “Chasing Ice” and one of the fastest moving glaciers in the world, will cease around 2020, according to a study by the University of Colorado Boulder.
A computer model predicts the retreat of the Columbia Glacier will stop when the glacier reaches a new stable position — roughly 15 miles upstream from the stable position it occupied prior to the 1980s. The team, headed by lead author William Colgan of the CU-Boulder headquartered Cooperative Institute for Research in Environmental Sciences, published its results today in The Cryosphere, an open access publication of the European Geophysical Union.
The Columbia Glacier is a large (425 square miles), multi-branched glacier in south-central Alaska that flows mostly south out of the Chugach Mountains to its tidewater terminus in Prince William Sound.
1938
Warming air temperatures have triggered an increase in the Columbia Glacier’s rate of iceberg calving, whereby large pieces of ice detach from the glacier and float into the ocean, according to Colgan. “Presently, the Columbia Glacier is calving about 2 cubic miles of icebergs into the ocean each year — that is over five times more freshwater than the entire state of Alaska uses annually,” he said. “It is astounding to watch.”
The imminent finish of the retreat, or recession of the front of the glacier, has surprised scientists and highlights the difficulties of trying to estimate future rates of sea level rise, Colgan said. “Many people are comfortable thinking of the glacier contribution to sea level rise as this nice predictable curve into the future, where every year there is a little more sea level rise, and we can model it out for 100 or 200 years,” Colgan said.
The team’s findings demonstrate otherwise, however. A single glacier’s contribution to sea level rise can “turn on” and “turn off” quite rapidly, over a couple of years, with the precise timing of the life cycle being difficult to forecast, he said. Presently, the majority of sea level rise comes from the global population of glaciers. Many of these glaciers are just starting to retreat, and some will soon cease to retreat.
2004
“The variable nature and speed of the life cycle among glaciers highlights difficulties in trying to accurately predict the amount of sea level rise that will occur in the decades to come,” Colgan said.
The Columbia Glacier was first documented in 1794 when it appeared to be stable with a length of 41 miles. During the 1980s it began a rapid retreat and by 1995 it was only about 36 miles long. By late 2000 it was about 34 miles long.
The loss of a massive area of the Columbia Glacier’s tongue has generated a tremendous number of icebergs since the 1980s. After the Exxon Valdez ran aground while avoiding a Columbia Glacier iceberg in 1989, significant resources were invested to understand its iceberg production. As a result, Columbia Glacier became one of the most well-documented tidewater glaciers in the world, providing a bank of observational data for scientists trying to understand how a tidewater glacier reacts to a warming climate.
Motivated by the compelling imagery of the Columbia Glacier’s retreat documented in the Extreme Ice Survey — James Balog’s collection of time-lapse photography of disappearing glaciers around the world — Colgan became curious as to how long the glacier would continue to retreat. To answer this question, the team of researchers created a flexible model of the Columbia Glacier to reproduce different criteria such as ice thickness and terminus extent.
The scientists then compared thousands of outputs from the computer model under different assumptions with the wealth of data that exists for the Columbia Glacier.
The batch of outputs that most accurately reproduced the well-documented history of retreat was run into the future to predict the changes the Columbia Glacier will most likely experience until the year 2100. The researchers found that around 2020 the terminus of the glacier will retreat into water that is sufficiently shallow to provide a stable position through 2100 by slowing the rate of iceberg production.
The speediness of the glacier’s retreat is due to the unique nature of tidewater glaciers, Colgan said. When warming temperatures melt the surface of a land glacier, the land glacier only loses its mass by run-off. But in tidewater glaciers, the changes in ice thickness resulting from surface melt can create striking changes in ice flow, triggering an additional dynamic process for retreat.
The dynamic response of the Columbia Glacier to the surface melt will continue until the glacier reaches its new stable position in 2020, at roughly 26 miles long. “Once the dynamic trigger had been pulled, it probably wouldn’t have mattered too much what happened to the surface melt — it was just going to continue retreating through the bedrock depression upstream of the pre-1980s terminus,” Colgan said.
Colgan next plans to attempt to use similar models to predict when the Greenland glaciers — currently the major contributors to sea level rise — will “turn off” and complete their retreats.
The future for the Columbia Glacier, however, looks bleak. “I think the hope was that once we saw climate change happening, we could act to prevent some irreversible consequences,” Colgan said, “but now we are only about eight years out from this retreat finishing — it is really sad. There is virtually no chance of the Columbia Glacier recovering its pre-retreat dimensions on human time-scales.”
The study was funded by NASA, and co-authors on the paper include W. Tad Pfeffer of CU-Boulder’s Institute of Arctic and Alpine Research, Harihar Rajaram of the CU-Boulder Department of Civil, Environmental, and Architectural Engineering, Waleed Abdalati of the National Aeronautic and Space Administration in Washington, D.C., and Balog of the Extreme Ice Survey in Boulder, Colo.
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CU-NOAA study shows summer climate change, mostly warming
0November 15, 2012
Analysis of 90 years of observational data has revealed that summer climates in regions across the globe are changing — mostly, but not always, warming –according to a new study led by a scientist from the Cooperative Institute for Research in Environmental Sciences headquartered at the University of Colorado Boulder.
“It is the first time that we show on a local scale that there are significant changes in summer temperatures,” said lead author CIRES scientist Irina Mahlstein. “This result shows us that we are experiencing a new summer climate regime in some regions.”
The technique, which reveals location-by-location temperature changes rather than global averages, could yield valuable insights into changes in ecosystems on a regional scale. Because the methodology relies on detecting temperatures outside the expected norm, it is more relevant to understand changes to the animal and plant life of a particular region, which scientists would expect to show sensitivity to changes that lie outside of normal variability.
“If the summers are actually significantly different from the way that they used to be, it could affect ecosystems,” said Mahlstein, who works in the Chemical Sciences Division of the National Oceanic and Atmospheric Administration’s Earth System Research Laboratory.
To identify potential temperature changes, the team used climate observations recorded from 1920 to 2010 from around the globe. The scientists termed the 30-year interval from 1920 to 1949 the “base period,” and then compared the base period to other 30-year test intervals starting every 10 years since 1930.
The comparison used statistics to assess whether the test interval differed from the base period beyond what would be expected due to yearly temperature variability for that geographical area.
Their analysis found that some changes began to appear as early as the 1960s, and the observed changes were more prevalent in tropical areas. In these regions, temperatures varied little throughout the years, so the scientists could more easily detect any changes that did occur, Mahlstein said.
The scientists found significant summer temperature changes in 40 percent of tropical areas and 20 percent of higher-latitude areas. In the majority of cases, the researchers observed warming summer temperatures, but in some cases they observed cooling summer temperatures.
“This study has applied a new approach to the question, ‘Has the temperature changed in local areas?’ ” Mahlstein said. The study is in press in the journal Geophysical Research Letters, a publication of the American Geophysical Union.
The study’s findings are consistent with other approaches used to answer the same question, such as modeling and analysis of trends, Mahlstein said. But this technique uses only observed data to come to the same result. “Looking at the graphs of our results, you can visibly see how things are changing,” she said.
In particular the scientists were able to look at the earlier time periods, note the temperature extremes, and observe that those values became more frequent in the later time periods. “You see how the extreme events of the past have become a normal event,” Mahlstein said.
The scientists used 90 years of data for their study, a little more than the average lifespan of a human being. So if inhabitants of those areas believe that summers have changed since they were younger, they can be confident it is not a figment of their imagination.
“We can actually say that these changes have happened in the lifetime of a person,” Mahlstein said.
Co-authors on the study were Gabriele Hegerl from the University of Edinburgh in Scotland and Susan Solomon from Massachusetts Institute of Technology.
CIRES is a joint institute of CU-Boulder and NOAA.
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2001-02 drought helped to shift Rocky Mountain pine beetle outbreak into epidemic
0November 5, 2012
A new University of Colorado Boulder study shows for the first time that episodes of reduced precipitation in the southern Rocky Mountains, especially during the 2001-02 drought, greatly accelerated development of the mountain pine beetle epidemic.
The study, the first ever to chart the evolution of the current pine beetle epidemic in the southern Rocky Mountains, compared patterns of beetle outbreak in the two primary host species, the ponderosa pine and lodgepole pine, said CU-Boulder doctoral student Teresa Chapman. The current mountain pine beetle outbreak in the southern Rockies — which range from southern Wyoming through Colorado and into northern New Mexico –is estimated to have impacted nearly 3,000 square miles of forests, said Chapman, lead study author.
While the 2001-02 drought in the West played a key role in pushing the pine beetle outbreak into a true regional epidemic, the outbreak continued to gain ground even after temperature and precipitation levels returned to levels nearer the long-term averages, said Chapman of CU-Boulder’s geography department. The beetles continued to decimate lodgepole pine forests by moving into wetter and higher elevations and into less susceptible tree stands — those with smaller diameter lodgepoles sharing space with other tree species.
“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.”
A paper on the subject was recently published in the journal Ecology. Co-authors on the study include CU-Boulder geography Professor Thomas Veblen and Tania Schoennagel, an adjunct faculty member in the geography department and a research scientist at CU-Boulder’s Institute of Arctic and Alpine Research. The National Science Foundation funded the study.
Mountain pine beetles are native insects that have shaped the forests of North America for thousands of years. They range from Canada to Mexico and are found at elevations from sea level to 11,000 feet. The effects of pine beetles are especially evident in recent years on Colorado’s Western Slope, including Rocky Mountain National Park, with a particularly severe epidemic occurring in Grand and Routt counties.
Chapman said the most recent mountain pine beetle outbreak began in the 1990s, primarily in scattered groups of lodgepole pine trees living at low elevations in areas of lower annual precipitation. Following the 2001-02 drought, the outbreak was “uncoupled” from the initial weather and landscape conditions, triggering a rise in beetle populations on the Western Slope and propelling the insects over the Continental Divide into the northern Front Range to infect ponderosa pine, Chapman said.
The current pine beetle epidemic in the southern Rocky Mountains was influenced in part by extensive forest fires that ravaged Colorado’s Western Slope from roughly 1850 to 1890, said Chapman. Lodgepole pine stands completely burned off by the fires were succeeded by huge swaths of seedling lodgepoles that eventually grew side by side into dense mature stands, making them easier targets for the pine beetles.
“The widespread burning associated with dry years in the 19th century set the stage for the current outbreak by creating vast areas of trees in the size classes most susceptible to beetle attack,” said Chapman.
Veblen said a 1980s outbreak of the pine beetle centered in Colorado’s Grand County ended when extremely low minimum temperatures were reached in the winters of 1983 and 1984, killing the beetle larvae. But during the current outbreak, minimum temperatures during all seasons have been persistently high since 1996, well above the levels of extreme cold shown to kill beetle larvae in laboratory experiments.
“This implies that under continued warming trends, future outbreaks will not be terminated until they exhaust their food supply — the pine tree hosts,” said Veblen.
Chapman said there has been a massive and unprecedented beetle epidemic in British Columbia, which also began in the early 1990s and has now has affected nearly 70,000 square miles. “It is hard to tell if this current beetle epidemic in the Southern Rockies is unprecedented,” she said. “While warm periods in the 16th century may have triggered a large beetle epidemic, any evidence would have been wiped out by the massive fires in the latter part of the 19th century.”
Veblen said while the rate of spread of the mountain pine beetle in lodgepole pine forests has declined in the southern Rocky Mountains during the past two years because of a depletion of host pine population, U.S. Forest Service surveys indicate the rate of beetle spread in ponderosa pine forests on the Front Range has increased sharply over the past three years. “The current study suggests that under the continued warmer climate, the spread of the beetle in ponderosa pines is likely to grow until that food source also is depleted,” Veblen said.
“Our results emphasize the importance of considering different patterns in the population dynamics of mountain pine beetles for different host species, even under similar regional-scale weather variations,” said Chapman. “Given the current outbreak of mountain pine beetles on the Front Range, their impact on ponderosa pines is certainly something that needs further study.”
A 2012 study by CU-Boulder Professor Jeffry Mitton and graduate student Scott Ferrenberg showed some Colorado pine beetles, which had been known to produce only one generation of tree-killing offspring annually, are producing two generations per year due to rising temperatures and a longer annual warm season. Because of the extra annual generation of beetles, there could be up to 60 times as many beetles attacking trees in any given year, according to the study.
In addition, a 2011 study led by CU-Boulder graduate student Evan Pugh indicated the infestation of trees by mountain pine beetles in the high country across the West could potentially trigger earlier snowmelt and increase water yields from snowpack that accumulates beneath affected trees.
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Frankenstorms are fueled by global warming
0October 30, 2012
Global Warming Raises Sea Levels, Alters Jet Stream, Makes Storms Stronger
SAN FRANCISCO— As America copes with the destruction caused by Hurricane Sandy, scientists with the Center for Biological Diversity are urging the Environmental Protection Agency to use the Clean Air Act to take emergency action against climate change. Global warming creates a “superstorm triple whammy” that helps turn nasty weather into a nightmare of killer winds and devastating storm surges.
“The terrifying truth is that America faces a future full of Frankenstorms,” said Shaye Wolf, Ph.D., the Center’s climate science director. “Climate change raises sea levels and supersizes storms. The threat of killer winds and crushing storm surges will grow by the year unless we get serious about tackling greenhouse gas pollution.”
Here’s how scientists say climate change feeds the superstorm triple whammy:
1. Global warming loads storms with more energy and more rainfall. A new study in the Proceedings of the National Academy of Sciences found that Katrina-magnitude Atlantic hurricanes have been twice as likely in warm years compared with cold years. In warm years hotter ocean temperatures add energy to storms and warmer air holds more moisture, causing storms to dump more rainfall. Global ocean temperatures hit their second-highest level on record in September, according to the National Oceanic and Atmospheric Administration.
2. Storm surge rides on higher sea levels, so more coastline floods during storms. In the northeastern United States, sea levels are rising three to four times faster than the global average, putting major U.S. cities at increased risk of flooding and storm surges, according to a June 2012 study in Nature Climate Change. The West Coast is not immune: Most of California could experience three or more feet of sea-level rise this century, heightening the risk of coastal flooding.
3. Melting sea ice and accelerating Arctic warming are causing changes in the jet stream that are bringing more extreme weather to the United States. Climate change in the Arctic is destabilizing the jet stream, causing bursts of colder air to drop down farther into the United States. In Sandy’s case, a collision with a cold front acted to turn the hurricane into a superstorm. Recent research, including studies by Georgia Institute of Technology and Rutgers University, has linked Arctic warming to increased risk of a variety of extreme weather events.
Deep and rapid greenhouse gas cuts are needed to reduce extreme weather risk. The Clean Air Act is America’s leading tool for curbing greenhouse gas pollution, and more than three dozen U.S. cities have joined the Center’s Clean Air Cities campaign urging the EPA to use the Clean Air Act to help reduce carbon in our atmosphere to no more than 350 parts per million, the level scientists say is needed to avoid catastrophic climate change.
The Center for Biological Diversity is a national, nonprofit conservation organization with more than 450,000 members and online activists dedicated to the protection of endangered species and wild places.
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And the 2012 Rubber Dodo Award goes to…Climate-change Denying Senator James Inhofe
0October 26, 2012
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TUCSON, Ariz.— Senator James Inhofe, one of Congress’ staunchest deniers of climate change and stalwart human obstacle to federal action on this unprecedented global crisis, is the lucky recipient of the Center for Biological Diversity’s 2012 Rubber Dodo Award, which is given annually to those who have done the most to drive endangered species extinct. Previous winners include the U.S. Chamber of Commerce (2011), former BP CEO Tony Hayward (2010), massive land speculator Michael Winer (2009), Alaska Gov. Sarah Palin (2008) and Interior Secretary Dirk Kempthorne (2007). When it comes to denying the climate crisis — the single-greatest threat now facing life on Earth — James Inhofe has few peers. The Oklahoma Republican is the ringleader of anti-science climate-deniers in Congress and a driving force behind the tragic lack of U.S. action to tackle this complex problem. 2012 saw the publication, to resoundingly little critical acclaim, of Sen. Inhofe’s book, The Greatest Hoax: How the Global Warming Conspiracy Threatens Your Future, by WND Press, an entity also known for its “birther” campaign against President Barack Obama.
“As climate change ravages the world, Senator Inhofe insists that we deny the reality unfolding in front of us and choose instead to blunder headlong into chaos,” said Kierán Suckling, the Center’s executive director. “Senator Inhofe gets the 2012 Rubber Dodo Award for being at the vanguard of the retrograde climate-denier movement.” This year is on track to become the warmest on record; some 40,000 temperature records have been broken in the United States in 2012 alone, while Arctic sea ice has melted to a record low. The year has also seen record droughts, crop failures, massive wildfires, floods and other unmistakable signals that manmade global warming is tightening its grip, threatening people and wildlife around the globe. “Senator Inhofe’s pet theory that climate change is an elaborate hoax would be hilarious, if only he weren’t an elected representative of the American people,” Suckling said. “If he were, say, a performance artist, it’d be really funny. But sadly he has the power to affect U.S. climate policy. The United States has a chance — and a duty — to take significant steps to slow the climate crisis, and a brief window of time before it’s too late for us to do so. Deniers like Inhofe, in positions of leadership, are dooming future generations of people to a far more difficult world.”
More than 15,000 people cast their votes in this year’s Rubber Dodo contest. Other official nominees were Sen. Jon Tester of Montana, who put a rider on a must-pass bill that stripped Endangered Species Act protection from wolves, and Shell Oil, a company bound and determined to pursue dangerous oil drilling in the Arctic Ocean. Background on the Dodo Its trusting nature led to its rapid extinction. By 1681 the dodo was extinct, having been hunted and outcompeted by humans, dogs, cats, rats, macaques and pigs. Humans logged its forest cover while pigs uprooted and ate much of the understory vegetation. The origin of the name dodo is unclear. It likely came from the Dutch word dodoor, meaning “sluggard,” the Portuguese word doudo, meaning “fool” or “crazy,” or the Dutch word dodaars meaning “plump-arse” (that nation’s name for the little grebe). The dodo’s reputation as a foolish, ungainly bird derives in part from its friendly naiveté and the very plump captives that were taken on tour across Europe. The animal’s reputation was cemented with the 1865 publication of Lewis Carroll’s Alice’s Adventures in Wonderland. Based on skeleton reconstructions and the discovery of early drawings, scientists now believe that the dodo was a much sleeker animal than commonly portrayed. The rotund European exhibitions were accidentally produced by overfeeding captive birds. The Center for Biological Diversity is a national, nonprofit conservation organization with more than 450,000 members and online activists dedicated to the protection of endangered species and wild places. |
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Here comes the snow City of Boulder warning
0October 24, 2012
City prepares for snowfall and reminds people to remove snow from sidewalks
Current weather forecasts indicate that an incoming storm may produce accumulated snow in Boulder beginning the night of Wednesday, Oct. 24, and continuing through Thursday, Oct. 25. The City of Boulder is preparing snow response crews in advance. Community members are asked to be mindful of the conditions, to prepare their vehicles as appropriate and to plan for extended commute times.
OK, it’s not that deep yet, but we likey. 
Snow Removal on City Streets
The city’s Public Works Department has snow crews on-call 24 hours a day, seven days a week to respond to changing weather conditions. During snowstorms, 16 plow trucks are active on Boulder’s streets. Six of the trucks distribute a liquid deicer, four spreader trucks distribute traction materials, and six trucks can distribute either material. Fifteen of the plow trucks drive predetermined routes while one “floater” truck responds to problem areas.
During the snowstorm, the city may spot-treat bridges and overpasses as needed to help reduce the buildup of ice and snow. Depending on the weather conditions, a liquid deicer may also be applied to streets and multi-use paths to continue melting the snowpack throughout the snowstorm. Spreader trucks will dispense a crystallized deicer for traction, where appropriate.
consistent with other Front Range communities, the city does not plow all residential streets since Boulder’s sunny climate typically melts most snow within a day or two and because residential plowing would increase costs by an estimated 200 percent. Plowing residential streets would also block driveways and cars parked on the streets. However, problem areas like particularly icy slopes, blocked storm drains or impassable sidewalks can be reported to the city for response. To report roadway or path problems, call the Street and Bikeway Maintenance Hotline at 303-413-7177.
Sidewalk Snow Removal
The Boulder Police Department is responsible for enforcing the city’s sidewalk snow removal ordinance. Property owners, tenants and landlords must clear their sidewalks within 24 hours after snow stops falling. Official snowfall reports are available on the National Weather Service website. Failure to remove snow from sidewalks before the 24-hour deadline may result in a summons and/or an abatement process. Abatement includes the use of a private snow removal contractor to clear the sidewalk. The property owner will be charged a $50 administrative fee, along with the contractor’s fee for removing the snow. To report a sidewalk snow violation, call Code Enforcement at 303-441-3333. Snow should be shoveled onto landscaping, not into the streets. Pushing snow into the streets creates hazards for bike commuters and pedestrians, and gutters clogged with snow may cause ice to form on the sidewalks.
The ICEBUSTERS program pairs residents who are physically unable to clear snow from their sidewalks with someone who can do the work for them. Seasonal and substitute volunteers are needed for this community program. To volunteer or learn more, please call 303-443-1933.
For more information about the city’s snow removal or for winter driving tips, visit www.bouldercolorado.gov/
For code enforcement information, call 303-441-3333 or visit the Boulder Police Department’s website at www.boulder-police.com.
