Climate News
Author: Outreach Office
CU-Boulder Professor to Travel State to Raise Awareness About Unprecedented Mountain Pine Beetle Epidemic
September 2, 2010
BOULDER – Professor Jeff Mitton of the CU-Boulder Ecology and Evolutionary Biology Department is hitting the road this year in an effort to educate Coloradans about the state’s pine beetle epidemic and the devastating toll the small insects are taking on Colorado’s forests.
The mountain pine beetle is in the midst of its largest epidemic in recorded history. The geographic infestation extends more than 1,000 miles, from New Mexico to the Yukon Territory. Mitton will visit eight Colorado communities where he will offer a public presentation on the life history of pine beetles and describe the struggle between attacking beetles and trees.
In addition to describing how tiny beetles can kill immense trees, he will discuss the role climate change has played in creating the epidemic. Small shifts in climate have expanded the geographic range in which pine beetles can thrive and extended their life cycle from one generation per year to two. Professor Mitton will also explain a surge in the populations of beetle predators, offering some hope for Colorado’s forests.
Mitton’s tour is sponsored by LearnMoreAboutClimate.colorado.edu, an online tool developed by CU-Boulder faculty and area scientists working in conjunction with the Office for University Outreach, which features five videos that localize climate change by pairing interviews with leading scientists and everyday Coloradans to explain how climate change is affecting our state. The site also offers teacher-developed and –tested model lessons for middle and high school students, including one that focuses on the pine beetle epidemic. The lessons are available at Learn More About Climate by clicking the “For Educators” tab.
During the fall semester, Mitton will make presentations at the following venues:
• Thursday, September 23, 2010 – The Longmont Public Library at 7 p.m.
• Tuesday, September 28, 2010 – Fort Lewis College Noble Hall, Room 125 at 7 p.m. in Durango
• Friday, October 1, 2010 – Blue Sage Center for the Arts at 7 p.m. in Paonia
• Tuesday, November 2, 2010 – Trinidad State Junior College in the Massari Theatre at 7 p.m.
The tour will resume during the spring semester with visits to Silverthorne, Vail, and Alamosa. The dates and locations of these presentations have yet to be finalized.
All presentations are free and open to the public.
CONTACT: Wynn Martens
303-492-4471
outreach@colorado.edu
New Study Shows How Tortoises, Alligators Thrived in High Arctic Some 50 Million Years Ago
August 24, 2010
A new study of the High Arctic climate roughly 50 million years ago led by the University of Colorado at Boulder helps to explain how ancient alligators and giant tortoises were able to thrive on Ellesmere Island well above the Arctic Circle, even as they endured six months of darkness each year.
The new study, which looked at temperatures during the early Eocene period 52 to 53 million years ago, also has implications for the impacts of future climate change as Arctic temperatures continue to rise, said University of Colorado at Boulder Associate Professor Jaelyn Eberle of the department of geological sciences, lead author of the study.
The team used a combination of oxygen isotope ratios from fossil bone and tooth enamel of mammals, fish and turtles that lived together on Ellesmere Island to estimate the average annual Eocene temperature for the site. They also were able to tease out temperature estimates for the warmest and coldest months of the year, critical data that should help scientists better understand past and future biodiversity in the High Arctic as the climate warms, including the geographical ranges and species richness of animals and plants.
The team concluded the average temperatures of the warmest month on Ellesmere Island during the early Eocene were from 66 to 68 degrees Fahrenheit (19-20 degrees C), while the coldest month temperature was about 32 to 38 degrees F (0-3.5 degrees C). "Our data gathered from multiple organisms indicate it probably did not get below freezing on Ellesmere Island during the early Eocene, which has some interesting implications," she said.
A paper on the subject was published in this month's issue of Earth and Planetary Science Letters. Co-authors included Henry Fricke from Colorado College, John Humphrey and Logan Hackett from the Colorado School of Mines, Michael Newbrey from University of Alberta, Edmonton, and Howard Hutchison from the University California, Berkeley. The National Science Foundation funded the study.
"This is arguably the most comprehensive data set for the early Eocene High Arctic, and certainly explains how alligators and giant tortoises could live on Ellesmere Island some 52 to 53 million years ago," said Eberle, who also is the curator of fossil vertebrates at the University of Colorado Museum of Natural History.
During the Eocene, Ellesmere Island -- which is adjacent to Greenland -- probably was similar to swampy cypress forests in the southeastern United States today, said Eberle. Eocene fossil evidence collected there in recent decades by various teams indicate the lush landscape hosted giant tortoises, aquatic turtles, large snakes, alligators, flying lemurs, tapirs, and hippo-like and rhino-like mammals.
The bone and tooth enamel of vertebrate fossils contains biogenic apatite -- a mineral that is fossilized after the death of living organisms and which can be used as a "flight recorder" to infer paleoclimate conditions. Since all of the fossil materials were from the same stratigraphic layer and locality, the oxygen isotope ratios from the animals are linked to the temperatures of both ingested river water and precipitation at the time, allowing them to better estimate temperatures in the Eocene both annually and seasonally, she said.
"We use the water that the animals were drinking as a proxy for paleotemperature," said Eberle. "In mammal fossils, for example, we can analyze the oxygen isotope ratios in a sequence along the length of a large fossil tooth and estimate the warm-month and cold-month averages during the Eocene because teeth grow year round. When it comes to oxygen isotope values in tooth enamel, what we found for these creatures is that you are what you drink," she said.
The team looked at teeth from a large, hippo-like mammal known as Coryphodon, as well as bones from bowfin fish and shells and bones from aquatic turtles from the Emydidae family, the largest and most diverse family of contemporary pond turtles. While Coryphodon and bowfins grew throughout the year, the turtles exhibited shell growth only during summer months, much like turtles that live today in non-equatorial areas.
"By looking at a host of animals with different physiologies, we were better able to pin down warm- and cold-month temperatures," she said. "Many aspects of biodiversity and species richness are related more to seasonal temperatures and ranges such as cold-month means rather than to mean annual temperature."
Bowfins -- which have a long dorsal fin and powerful jaws -- inhabit a variety of waters today from the Saint Lawrence River drainage in Quebec south to Florida and Texas. The team also compared the ranges of bowfins, aquatic turtles and giant tortoises of today with their ranges in the Eocene to help them estimate temperatures, according to co-author Newbrey, an expert in both contemporary and extinct fishes.
Eberle said the new study implies Eocene alligators could withstand slightly cooler winters than their present-day counterparts, although data from captive alligators show they are heartier than other members of the crocodilian family and can survive short intervals of subfreezing temperatures by submerging themselves in the water.
In contrast, the existence of large land tortoises in the Eocene High Arctic is still somewhat puzzling, said Eberle, since today's large tortoises inhabit places like the Galapagos Islands where the cold-month average temperature is about 50 degrees F (10 degrees C.)
But during the late Pleistocene period some 10,000 to 50,000 years ago -- when air temperatures were comparable to those today -- large land tortoises were found as far north as present-day Pennsylvania and Illinois, Eberle said. This suggests their present range in the Americas does not represent their fullest geographic range as allowed by climate. Factors like hunting by early Native Americans and the past extent of glaciers probably are playing a role in today's distribution of giant tortoises, she said.
Eberle, who calls the new results "a deep time analogue" for today's rapidly warming Arctic region, said quantitative estimates of early Eocene climate conditions at high latitudes like Ellesmere Island are rare and often contradictory. Previous estimates of the early Eocene mean annual temperatures have ranged from 39 to 68 degrees F (4 to 20 degrees C), a temperature range equivalent to geographic ranges reaching from Canada to Florida.
There is high concern by scientists over a proposal to mine coal on Ellesmere Island at the ancient fossil site by WestStar Resources Inc. headquartered in Vancouver, British Columbia, Eberle said. "Sites like this are unique and extremely valuable resources that are of international importance, and shouldn't be allowed to disappear," she said. "Our concern is that coal mining activities could damage such sites and they will be lost forever."
Today Ellesmere Island is one of the coldest, driest environments on Earth and features tundra, permafrost, ice sheets, sparse vegetation and few mammals. The temperatures range from roughly minus 37 degrees F in winter (minus 38 C) to 48 degrees F (8 degrees C) in summer.
The new study foreshadows the impacts of continuing global warming on Arctic plants and animals, Eberle said. Temperatures in the Arctic are rising twice as fast as those at mid-latitudes as greenhouse gases build up in Earth's atmosphere, due primarily to human activities like fossil fuel burning and deforestation, according to climate scientists.
Contact
Jaelyn Eberle, 303-492-8069
Jaelyn.Eberle@colorado.edu
Jim Scott, 303-492-3114
Jim.Scott@colorado.edu
Ice Core Drilling Effort Involving CU-Boulder Should Help Assess Abrupt Climate Change Risks
An international science team involving the University of Colorado at Boulder that is working on the North Greenland Eemian Ice Drilling project hit bedrock July 27 after two summers of work, drilling down more than 1.5 miles in an effort to help assess the risks of abrupt future climate change on Earth.
Led by Denmark and the United States, the team recovered ice from the Eemian interglacial period from about 115,000 to 130,000 years ago, a time when temperatures were 3.6 to 5.4 degrees Fahrenheit above today's temperatures. During the Eemian -- the most recent interglacial period on Earth -- there was substantially less ice on Greenland, and sea levels were more than 15 feet higher than today.
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. The new effort, known as NEEM, has allowed researchers to obtain thicker, more intact annual ice layers near the bottom of the core that are expected to contain crucial information about how Earth's climate functions, said CU-Boulder Professor Jim White, lead U.S. investigator on the project.
"Scientists from 14 countries have come together in a common effort to provide the science our leaders and policy makers need to plan for our collective future," said White, who directs CU-Boulder's Institute of Arctic and Alpine Research and is an internationally known ice core expert. "I hope that NEEM is a foretaste of the kind of cooperation we need for the future, because we all share the world."
Annual ice layers formed over millennia in Greenland by compressed snow reveal information on past temperatures and precipitation levels, as well as the contents of ancient atmospheres, said White. Ice cores from previous drilling efforts revealed temperature spikes of more than 20 degrees Fahrenheit in just 50 years in the Northern Hemisphere.
White said the new NEEM ice cores will more accurately portray past changes in temperatures and greenhouse gas concentrations in the Eemian, making it the best analogue for future climate change on Earth. An international study released by the National Oceanic and Atmospheric Administration last week showed the first decade of the 21st century was the warmest on record for the planet.
The NEEM project involves 300 scientists and students and is led by Professor Dorthe Dahl-Jensen, director of the University of Copenhagen's Centre of Ice and Climate. The United States portion of the effort is funded by the National Science Foundation's Office of Polar Programs.
The two meters of ice just above bedrock from NEEM -- which is located at one of the most inaccessible parts of the Greenland ice sheet -- go beyond the Eemian interglacial period into the previous ice age and contains rocks and other material that have not seen sunlight for hundreds of thousands of years, said White. The researchers expect the cores to be rich in DNA and pollen that can tell scientists about the plants that existed in Greenland before it became covered with ice.
The cores samples are being studied in detail using a suite of measurements, including stable water isotopes that reveal information about temperature and moisture changes back in time. The team is using state-of-the art laser instruments to measure the isotopes, as well as atmospheric gas bubbles trapped in the ice and ice crystals to understand past variations in climate on a year-by-year basis, said White.
As part of the project, the researchers want to determine how much smaller the Greenland ice sheet was 120,000 years ago when the temperatures were higher than present, as well as how much and how fast the Greenland ice sheet contributed to sea level. "We expect that our findings will increase our knowledge on the future climate system and increase our ability to predict the speed and final height of sea level rise during the Eemian," said Dahl-Jensen.
The NEEM facility includes a large dome, a drilling rig to extract 3-inch in diameter ice cores, drilling trenches, labs and living quarters. The United States is leading the laboratory analysis of atmospheric gases trapped in bubbles within the cores, including greenhouse gases like carbon dioxide and methane.
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.
Other CU-Boulder participants include postdoctoral researcher Vasilii Petrenko and doctoral student Tyler Jones. White also is a professor in CU-Boulder's geological sciences department.
The vast majority of climate scientists attribute rising temperatures on Earth to increased greenhouse gases pumped into the atmosphere as a result of human activity. In 2008 The Intergovernmental Panel on Climate Change concluded that temperatures on Earth could rise by as much as 10 degrees F above today's temperatures in the next century, primarily due to atmospheric greenhouse gases.
Additional information and photos on the NEEM effort can be found on the web at http:// www.neem.ku.dk.
More information on the international NEEM deep drilling project can be obtained either by emailing White or contacting NEEM Field Operation Manager J.P. Steffensen at +299 84 11 51 or +299 52 41 25 or emailing him at neem-fom@gfy.ku.dk
-CU-
Contact
Jim White, 303-492-5494
James.White@colorado.edu
Jim Scott, 303-492-3114
Jim.Scott@colorado.edu
CU-Boulder to Study Environmental Fate of Oil Dispersants Used in Gulf Cleanup
Environmental engineering faculty and students at the University of Colorado at Boulder are launching a study this month to determine the environmental fate of chemical dispersants being used in the Gulf oil spill cleanup.
Professor and water treatment expert Karl Linden will lead the one-year study, which is funded by an $82,319 RAPID-response grant from the National Science Foundation. Linden will work with Assistant Professor Fernando Rosario-Ortiz, who brings additional expertise in environmental chemistry and oxidation processes.
"Dispersants are designed to break up large globules of oil into smaller droplets that enhance biodegradation," Linden said. "However, the use of dispersants is being carried out in ways never envisioned."
Dispersants are being sprayed onto the ocean in larger quantities than ever before and injected deep underwater at the source of the oil leak, a new practice with unknown consequences, according to Linden.
The investigations will focus on Corexit, a proprietary chemical being used by BP, and on photochemical degradation -- driven by sunlight -- which is believed to be an important mechanism in the breakdown of the dispersant.
"Our research will focus on how efficient sunlight-driven processes are at degrading these compounds," Rosario-Ortiz said. "This represents a significant challenge based on the chemical complexity of these dispersants, and the different environmental factors that will interfere with these processes."
The team plans to travel to the Gulf area in late August to obtain water samples and coordinate with other studies in the area. Prior to that, the researchers will develop an analytical method to monitor the chemical constituents in the dispersant, and investigate fundamentals of the dispersant's decay in the laboratory using model ocean water and a solar simulator.
At the conclusion of the study, the team will model and estimate the half-life of identifiable chemicals in the dispersant based on sunlight conditions experienced in the Gulf of Mexico and predict their photochemical fate.
Linden and Rosario-Ortiz also plan to integrate their activities and findings into their fall undergraduate and graduate classes on environmental engineering and water chemistry.
Contact
Karl Linden, 303-492-4798
Fernando Rosario-Ortiz, 303-492-7607
Carol Rowe, 303-492-7426
Sea Levels Rising in Parts of Indian Ocean, According to New Study
July 13, 2010
Newly detected rising sea levels in parts of the Indian Ocean, including the coastlines of the Bay of Bengal, the Arabian Sea, Sri Lanka, Sumatra and Java, appear to be at least partly a result of human-induced increases of atmospheric greenhouse gases, says a study led by the University of Colorado at Boulder.
The study, which combined sea surface measurements going back to the 1960s and satellite observations, indicates anthropogenic climate warming likely is amplifying regional sea rise changes in parts of the Indian Ocean, threatening inhabitants of some coastal areas and islands, said CU-Boulder Associate Professor Weiqing Han, lead study author. The sea level rise -- which may aggravate monsoon flooding in Bangladesh and India -- could have far-reaching impacts on both future regional and global climate.
The key player in the process is the Indo-Pacific warm pool, an enormous, bathtub-shaped area of the tropical oceans stretching from the east coast of Africa west to the International Date Line in the Pacific. The warm pool has heated by about 1 degree Fahrenheit, or 0.5 degrees Celsius, in the past 50 years, primarily caused by human-generated increases of greenhouse gases, said Han.
"Our results from this study imply that if future anthropogenic warming effects in the Indo-Pacific warm pool dominate natural variability, mid-ocean islands such as the Mascarenhas Archipelago, coasts of Indonesia, Sumatra and the north Indian Ocean may experience significantly more sea level rise than the global average," said Han of CU-Boulder's atmospheric and oceanic sciences department.
A paper on the subject was published in this week's issue of Nature Geoscience. Co-authors included Balaji Rajagopalan, Xiao-Wei Quan, Jih-wang Wang and Laurie Trenary of CU-Boulder, Gerald Meehl, John Fasullo, Aixue Hu, William Large and Stephen Yeager of the National Center for Atmospheric Research in Boulder, Jialin Lin of Ohio State University, and Alan Walcraft and Toshiaki Shinoda of the Naval Research Laboratory in Mississippi.
While a number of areas in the Indian Ocean region are showing sea level rise, the study also indicated the Seychelles Islands and Zanzibar off Tanzania's coastline show the largest sea level drop. Global sea level patterns are not geographically uniform, and sea rise in some areas correlate with sea level fall in other areas, said NCAR's Meehl.
The Indian Ocean is the world's third largest ocean and makes up about 20 percent of the water on Earth's surface. The ocean is bounded on the west by East Africa, on the north by India, on the east by Indochina and Australia, and on the south by the Southern Ocean off the coast of Antarctica.
The patterns of sea level change are driven by the combined enhancement of two primary atmospheric wind patterns known as the Hadley circulation and the Walker circulation. The Hadley circulation in the Indian Ocean is dominated by air currents rising above strongly heated tropical waters near the equator and flowing poleward, then sinking to the ocean in the subtropics and causing surface air to flow back toward the equator.
The Indian Ocean's Walker circulation causes air to rise and flow westward at upper levels, sink to the surface and then flow eastward back toward the Indo-Pacific warm pool. "The combined enhancement of the Hadley and Walker circulation form a distinct surface wind pattern that drives specific sea level patterns," said Han.
The international research team used several different sophisticated ocean and climate models for the study, including the Parallel Ocean Program -- the ocean component of NCAR's widely used Community Climate System Model. In addition, the team used a wind-driven, linear ocean model for the study.
"Our new results show that human-caused changes of atmospheric and oceanic circulation over the Indian Ocean region -- which have not been studied previously -- are the major cause for the regional variability of sea level change," wrote the authors in Nature Geoscience.
Han said that based on all-season data records, there is no significant sea level rise around the Maldives. But when the team looked at winter season data only, the Maldives show significant sea level rise, a cause for concern. The smallest Asian country, the Maldives is made up of more than 1,000 islands -- about 200 of which are inhabited by about 300,000 people -- and are on average only about five feet above sea level.
The complex circulation patterns in the Indian Ocean may also affect precipitation by forcing even more atmospheric air down to the surface in Indian Ocean subtropical regions than normal, Han speculated. "This may favor a weakening of atmospheric convection in the subtropics, which may increase rainfall in the eastern tropical regions of the Indian Ocean and increase drought in the western equatorial Indian Ocean region, including east Africa," Han said.
The new study indicates that in order to document sea level change on a global scale, researchers also need to know the specifics of regional sea level changes that will be important for coastal and island regions, said NCAR's Hu. Along the coasts of the northern Indian Ocean, seas have risen by an average of about 0.5 inches, or 13 millimeters, per decade.
"It is important for us to understand the regional changes of the sea level, which will have effects on coastal and island regions," said Hu.
The study was funded by a number of organizations, including NCAR, the National Science Foundation, NASA and the U.S. Department of Energy.
Contact
Weiqing Han, CU, 303-735-3079
Weiqing.Han@colorado.edu
Aixue Hu, NCAR, 303-497-1334
ahu@ucar.edu
Jim Scott, 303-492-3114
Arctic Climate May be More Sensitive to Warming Than Thought, Says New Study
June 29, 2010
A new study shows the Arctic climate system may be more sensitive to greenhouse warming than previously thought, and that current levels of Earth's atmospheric carbon dioxide may be high enough to bring about significant, irreversible shifts in Arctic ecosystems.
Led by the University of Colorado at Boulder, the international study indicated that while the mean annual temperature on Ellesmere Island in the High Arctic during the Pliocene Epoch 2.6 to 5.3 million years ago was about 34 degrees Fahrenheit, or 19 degrees Celsius, warmer than today, CO2 levels were only slightly higher than present. The vast majority of climate scientists agree Earth is warming due to increased concentrations of heat-trapping atmospheric gases generated primarily by human activities like fossil fuel burning and deforestation.
The team used three independent methods of measuring the Pliocene temperatures on Ellesmere Island in Canada's High Arctic. They included measurements of oxygen isotopes found in the cellulose of fossil trees and mosses that reveal temperatures and precipitation levels tied to ancient water, an analysis of the distribution of lipids in soil bacteria which correlate with temperature, and an inventory of ancient Pliocene plant groups that overlap in range with contemporary vegetation.
"Our findings indicate that CO2 levels of approximately 400 parts per million are sufficient to produce mean annual temperatures in the High Arctic of approximately 0 degrees Celsius (32 degrees F)," Ballantyne said. "As temperatures approach 0 degrees Celsius, it becomes exceedingly difficult to maintain permanent sea and glacial ice in the Arctic. Thus current levels of CO2 in the atmosphere of approximately 390 parts per million may be approaching a tipping point for irreversible ice-free conditions in the Arctic."
A paper on the subject is being published in the July issue of the journal Geology. Co-authors included David Greenwood of Brandon University in Manitoba, Canada, Jaap Sinninghe Damste of the Royal Netherlands Institute for Sea Research, Adam Csank of the University of Arizona, Natalia Rybczynski of the Canadian Museum of Nature in Ottawa and Jaelyn Eberle, curator of fossil vertebrates at the University of Colorado Museum of Natural History and an associate professor in the geological sciences department.
Arctic temperatures have risen by about 1.8 degrees F, or 1 degree C, in the past two decades in response to anthropogenic greenhouse warming, a trend expected to continue in the coming decades and centuries, said Ballantyne. Greenhouse gases in the atmosphere have risen from about 280 parts per million during the pre-industrial era on Earth to about 390 parts per million today.
During the Pliocene, Ellesmere Island hosted forests of larch, dwarf birch and northern white cedar trees, as well as mosses and herbs, including cinquefoils. The island also was home to fish, frogs and now extinct mammals that included tiny deer, ancient relatives of the black bear, three-toed horses, small beavers, rabbits, badgers and shrews. Because of the high latitude, the Ellesmere Island site on the Strathcona Fiord was shrouded by darkness six months out of the year, said Rybczynski.
Fossils are often preserved in a process known as permineralization, in which mineral deposits form internal casts of organisms. But at the Ellesmere Island site known as the "Beaver Pond site," organic materials -- including trees, plants and mosses -- have been "mummified" in peat deposits, allowing the researchers to conduct detailed, high-quality analyses, said Eberle.
Ballantyne said the high level of preservation of trees and mosses at Ellesmere Island allowed the team to measure the ratio of oxygen isotopes in plant cellulose, providing information on water absorbed from precipitation during the Pliocene and which yielded estimates of past surface temperatures. The team also compared data on the width of tree rings in larch trees at the Beaver Pond site to trees at lower latitudes today to help them estimate past temperatures and precipitation levels.
The researchers also analyzed the distribution of ancient membrane lipids from soil bacteria known as tetraethers, which correlate to temperature. The chemical structure of the fossilized tetraethers makes them highly sensitive to both temperature and acidity, or pH, said Ballantyne.
The last line of evidence put forward by the CU-Boulder-led team was a comparison of Pliocene ancient vegetation at the site with vegetation present today, providing a clear "climate window" showing the overlap of the two time periods. "The results of the three independent temperature proxies are remarkably consistent," said Eberle. "We essentially were able to ‘read' the vegetation in order to estimate air temperatures in the Pliocene."
Today, Ellesmere Island is a polar desert that features tundra, permafrost, ice sheets, sparse vegetation and a few small mammals. Temperatures range from roughly minus 37 degrees F, or minus 38 degrees C, in winter to 48 degrees F, or 9 degrees C, in summer. The region is one of the coldest, driest environments on Earth.
"Our findings are somewhat disconcerting regarding the temperatures and greenhouse gas levels during the Pliocene," said Eberle. "We already are seeing evidence of both mammals and birds moving northward as the climate warms, and I can't help but wonder if the Arctic is headed toward conditions similar to those that existed during the Pliocene."
Elevated Arctic temperatures during the Pliocene -- which occurred shortly before Earth plunged into an ice age about 2.5 million years ago -- are thought to have been driven by the transfer of heat to the polar regions and perhaps by decreased reflectivity of sunlight hitting the Arctic due to a lack of ice, said Ballantyne. One big question is why the Arctic was so sensitive to warming during this period, he said.
Multiple feedback mechanisms have been proposed to explain the amplification of Arctic temperatures, including the reflectivity strength of the sun on Arctic ice and changes in vegetation seasonal cloud cover, said Ballantyne. "I suspect that it is the interactions between these different feedback mechanisms that ultimately produce the warming temperatures in the Arctic."
In 2009, CU-Boulder's National Snow and Ice Data Center showed the September Arctic sea ice extent was 649,000 square miles, or 1,680,902 square kilometers, below the 1979-2000 average, and is declining at a rate of 11.2 percent per decade. Some climate change experts are forecasting that the Arctic summers will become ice-free summers within a decade or two.
In addition to its exceptional preservation of fossil wood, plants, insects and mollusks, the Beaver Pond site on Ellesmere Island is the only reported Pliocene fossil site in the High Arctic to yield vertebrate remains, said Rybczynski.
Eberle said there is high concern by scientists over a proposal to mine coal on Ellesmere Island near the Beaver Pond site by WestStar Resources Inc. headquartered in Vancouver, British Columbia. "Paleontological sites like the Beaver Pond site are unique and extremely valuable resources that are of international importance," said Eberle. "Our concern is that coal mining activities could damage such sites and they will be lost forever."
The study was funded by the National Science Foundation, the Natural Science and Engineering Research Council in Canada, the Netherlands Organization for Scientific Research and the European Research Council.
Contact
Ashley Ballantyne
Ashley.Ballantyne@colorado.edu
Jaelyn Eberle, 303-492-8069
Jaelyn.Eberle@colorado.edu
Jim Scott, 303-492-3114
Jim.Scott@colorado.edu
New Teacher-Tested Model Climate Change Lessons Now Available From CU-Boulder
If you’re a middle or high school teacher seeking innovative ways to engage students in the science of climate change, look no further. CU-Boulder is offering a series of teacher-developed and teacher-tested model lessons on its LearnMoreAboutClimate.colorado.edu website.
These problem-based lessons were developed by teams of Colorado middle and high school teachers along with university scientists and science education researchers who participated in the "Making the Global Local: Colorado Climate Curriculum Workshop" hosted by CU-Boulder last summer. During the fall 2009 semester, teachers tested the lessons in their own classrooms and worked with other workshop participants to refine them.
The result is a set of model lessons that focus on the following single driving questions:
• Evidence of Climate Change — How would we know if Colorado's climate is changing and how will it affect me?
• Mountain Pine Beetles — Why are our forests dying?
• Zoo Poo — Does burning poo at the Denver Zoo reduce CO2?
• Modeling Climate — What makes you hot?
All of these topics are linked to one or more of five Learn More About Climate videos, which localize climate change by pairing interviews with leading climate scientists with everyday Coloradans who explain how climate change is affecting Colorado communities.
Each lesson outlines the essential principles, learning objectives and Colorado State Science Standards addressed and is accompanied by a variety of classroom materials that can be adapted for learners in grades 5-12. Suggestions for potential extensions and links to additional climate change curricula and other classroom resources are also provided.
To access the model lessons, visit LearnMoreAboutClimate.colorado.edu and click on the “For Educators” tab.
“Making the Global Local” and LearnMoreAboutClimate.colorado.edu are collaborative initiatives that involve CU-Boulder faculty and national institute scientists. Both are coordinated by the Office for University Outreach in the Division of Continuing Education and Professional Studies (CEPS).
Contact:
Erin Furtak
Assistant Professor, School of Education
303-885-6426
Erin.Furtak@Colorado.edu
Wynn Martens
Office for University Outreach
303-908-1103
Wynn.Martens@Colorado.edu
10 Recycling Facts for Earth Day
10 Recycling Facts
- Americans throw away enough aluminum to rebuild our entire commercial fleet of airplanes every 3 months. Environmental Defense Fund
- About 80% of what Americans throw away is recyclable, yet our recycling rate is just 28%. Environmental Protection Agency
- Over ½ million trees are saved each year by recycling paper in Boulder County. Eco-Cycle
- Recycling creates 6 times as many jobs as landfilling. Colorado Recycles
- Recycling glass instead of making it from silica sand reduces mining waste by 70%, water use by 50%, and air pollution by 20%. Environmental Defense Fund
- Recycling just one aluminum can saves enough energy to operate a TV for 3 hours. Eco-Cycle
- If we recycled all of the newspapers printed in the U.S. on a typical Sunday, we would save 550,000 trees--or about 26 million trees per year. California Department of Conservation
- The energy saved each year by steel recycling is equal to the electrical power used by 18 million homes each year - or enough energy to last Los Angeles residents for eight years. Steel Recycling Institute
- If every household in the U.S. replaced just one roll of 1,000 sheet virgin fiber bathroom tissues with 100% recycled ones, we could save: 373,000 trees, 1.48 million cubic feet of landfill space, and 155 million gallons of water. Seventh Generation Co.
- Recycling 1 ton of paper saves 17 trees, 2 barrels of oil (enough to run the average car for 1,260 miles), 4,100 kilowatts of energy (enough power for the average home for 6 months), 3.2 cubic yards of landfill space, and 60 pounds of air pollution. Trash to Cash
(Compiled by the International English Center in the Division of Continuing Education and Professional Studies at CU-Boulder)
Traditional Inuit Knowledge Combines With Science to Shape Arctic Weather Insights
Using skills passed down through generations, Inuit forecasters living in the Canadian Arctic look to the sky to tell by the way the wind scatters a cloud whether a storm is on the horizon or if it's safe to go on a hunt.
Thousands of miles away in a lab tucked in Colorado's Rocky Mountains, scientists take data measurements and use the latest computer models to predict weather. They are two practices serving the same purpose that come from disparate worlds.
But in the past 20 years, something has run amok with Inuit forecasting. Old weather signals don't seem to mean what they used to. The cloud that scatters could signal a storm that comes in an hour instead of a day.
Now researchers are combining indigenous environmental knowledge with modern science to learn new things about what's happening to the Arctic climate.
"It's interesting how the western approach is often trying to understand things without necessarily experiencing them," said Elizabeth Weatherhead, a research scientist with the University of Colorado at Boulder's Cooperative Institute for Research in Environmental Sciences. "With the Inuit, it's much more of an experiential issue, and I think that fundamental difference brings a completely different emphasis both in defining what the important scientific questions are, and discerning how to address them."
For years, researchers had heard reports of unpredictable weather coming in from Arctic communities. But the stories didn't seem to match up with the numbers. By scientific measurement, weather around the world appeared to be growing more persistent with less variation. The disparity left scientists scratching their heads, said Weatherhead.
"I had been hearing about this problem from other environmental statisticians for a number of years," said Weatherhead, who also works closely with the National Oceanic and Atmospheric Administration's Earth System Research Laboratory in Boulder, Colo., and who is chief author on a new study on the subject. "But the Inuit used a different language than what we statisticians used, and none of us could really figure out what matched up with their observations."
That's where Shari Gearheard, a scientist with CU-Boulder's National Snow and Ice Data Center, also part of CIRES, comes in. Gearheard lives in Clyde River, Nunavut, Canada, an Inuit community on eastern Baffin Island, and for the past 10 years has been working with Inuit hunters and elders to document their knowledge of the environment and environmental change.
Weather has a special importance in Arctic environments, where a reliable forecast can mean the difference between life and death. There are members of the Inuit community who possess the skills to predict the weather, but that knowledge is dying off as both the culture and climate change, according to the scientists.
"The impacts of that are a loss of confidence in those forecasters and concerns about incorrect forecasts," said Gearheard. Forecasters don't want to send somebody out to go hunting if they're going to be unsafe and be in poor weather conditions."
Gearheard meticulously collects the stories told to her by the Inuit and makes systematic records of indigenous environmental knowledge. Through this, patterns begin to emerge, she said.
Of special importance were changes experienced by the Inuit during the spring, a time of transition for many environmental processes. During spring, the Inuit would notice that the top layer of the snow melted during the day and then would refreeze at night, forming a crust.
"In fact, in a lot of places, the season is named after a particular process by the Inuit," said Gearheard. "In cases like this where the Inuit are not seeing that process anymore, it is an indicator to them that something had changed."
Gearheard's records created a resolution of detail for Arctic weather observation that, by bringing the two studies together, gave Weatherhead the information she needed to bridge indigenous knowledge with scientific knowledge. "What was incredibly helpful was Shari's detailed description of what they were experiencing on what sort of timescales," said Weatherhead. "That really allowed us to start focusing on our statistical tests and try to find exactly what matched their observations."
Statistical analysis of day-to-day temperatures at Baker Lake, Nunavut, showed that in May and June the persistence of temperature had recently declined, matching Inuit reports of greater unpredictability at that season. "People hadn't previously looked at persistence in this way," said CIRES fellow Roger Barry, also director of the World Data Center for Glaciology at the National Snow and Ice Data Center at CU-Boulder and a study co-author along with Gearheard.
What they found was a scientific story more in line with what people were witnessing on the ground. Weather along the Arctic latitudes was behaving more unpredictably than in other parts of the world.
"That's an incredibly important parameter to care about," said Weatherhead. "The way I try to describe it to some people is if we get an inch of rain out at my house in the month of July, I don't need to turn on the sprinklers. But if we get an inch of rain on July 1, and no rain after that, my lawn is dead.
"Ecosystems have evolved under a certain type of pattern. So if that is changing, that could be just as important as a small increase in temperature or some of the other changes we're talking about," Weatherhead said.
The new study helps scientists refine and test climate models, while also providing such models with a new category of information to consider, said Weatherhead. And Gearheard's work with the Inuit is demonstrating the value of indigenous environmental knowledge to modern climate science.
"When we first started talking about this, indigenous knowledge didn't have the place it does now in research," Gearheard said. "It's growing. People are becoming more familiar with it, more respectful of it."
Weatherhead and Gearheard said they are intrigued by the insights that incorporate indigenous knowledge and climate studies, but they don't want to stop there. The new study has sparked an interest in the type of environmental knowledge other communities could provide to climate scientists, from ranchers and farmers to indigenous groups. "When you treat these perspectives as different forms of evidence or knowledge and see where that takes you, that is when exciting stuff happens," said Gearheard.
The study appears this month in the journal Global Environmental Change. The National Science Foundation and the Social Sciences and Humanities Research Council of Canada provided funding for the study. Photos and a podcast interview with the study authors can be downloaded at cires.colorado.edu/news.
Contact:
Elizabeth Weatherhead, 303-497-6653
Betsy.Weatherhead@colorado.edu
Roger Barry, 303-492-548
Roger.Barry@colorado.edu
Morgan Heim, CIRES, 303-492-6289
Morgan.Heim@cires.colorado.edu
Greenland Ice Sheet Losing Ice Mass on Northwest Coast, Says New International Study
March 23, 2010
Ice loss from the Greenland ice sheet, which has been increasing during the past decade over its southern region, is now moving up its northwest coast, according to a new international study.
Led by the Denmark Technical Institute's National Space Institute in Copenhagen and involving the University of Colorado at Boulder, the study indicated the ice-loss acceleration began moving up the northwest coast of Greenland starting in late 2005. The team drew their conclusions by comparing data from NASA's Gravity and Recovery Climate Experiment satellite system, or GRACE, with continuous GPS measurements made from long-term sites on bedrock on the edges of the ice sheet.
The data from the GPS and GRACE provided the researchers with monthly averages of crustal uplift caused by ice-mass loss. The team combined the uplift measured by GRACE over United Kingdom-sized chunks of Greenland while the GPS receivers monitor crustal uplift on scales of just tens of miles. "Our results show that the ice loss, which has been well documented over southern portions of Greenland, is now spreading up along the northwest coast," said Shfaqat Abbas Khan, lead author on a paper that will appear in Geophysical Research Letters.
The team found that uplift rates near the Thule Air Base on Greenland's northwest coast rose by roughly 1.5 inches, or about 4 centimeters, from October 2005 to August 2009. Although the low resolution of GRACE -- a swath of about 155 miles, or 250 kilometers across -- is not precise enough to pinpoint the source of the ice loss, the fact that the ice sheet is losing mass nearer to the ice sheet margins suggests the flows of Greenland outlet glaciers there are increasing in velocity, said the study authors.
"When we look at the monthly values from GRACE, the ice mass loss has been very dramatic along the northwest coast of Greenland," said CU-Boulder physics Professor and study co-author John Wahr, also a fellow at CU-Boulder's Cooperative Institute for Research in Environmental Sciences.
"This is a phenomenon that was undocumented before this study," said Wahr. "Our speculation is that some of the big glaciers in this region are sliding downhill faster and dumping more ice in the ocean."
Other co-authors on the new GRL study included Michael Bevis and Eric Kendrick from Ohio State University and Isabella Velicogna of the University of California-Irvine, who also is a scientist at NASA's Jet Propulsion Laboratory. GRL is published by the American Geophysical Union.
A 2009 study published in GRL by Velicogna, who is a former CU-Boulder research scientist, showed that between April 2002 and February 2009, the Greenland ice sheet shed roughly 385 cubic miles of ice. The mass loss is equivalent to about 0.5 millimeters of global sea-level rise per year.
"These changes on the Greenland ice sheet are happening fast, and we are definitely losing more ice mass than we had anticipated, " said Velicogna. "We also are seeing this ice mass loss trend in Antarctica, a sign that warming temperatures really are having an effect on ice in Earth's cold regions."
Researchers have been gathering data from GRACE since NASA launched the system in 2002. Two GRACE satellites whip around Earth 16 times a day separated by 137 miles and measure changes in Earth's gravity field caused by regional shifts in the planet's mass, including ice sheets, oceans and water stored in the soil and in underground aquifers.
"GRACE is unique in that it allows us to see changes in the ice mass in almost real time," said Velicogna. "Combining GRACE data with the separate signals from GPS stations gives us a very powerful tool that improves our resolution and allows us to better understand the changes that are occurring."
In addition to monitoring the Thule GPS receiver in northwest Greenland as part of the new GRL study, the team also is taking data from GPS receivers in southern Greenland near the towns of Kellyville and Kulusuk. An additional 51 permanent GPS stations recently set up around the edges of the Greenland ice sheet should be useful to measure future crustal uplift and corresponding ice loss, said Wahr.
"If this activity in northwest Greenland continues and really accelerates some of the major glaciers in the area -- like the Humboldt Glacier and the Peterman Glacier -- Greenland's total ice loss could easily be increased by an additional 50 to 100 cubic kilometers (12 to 24 cubic miles) within a few years," said Khan.
The study was funded by NASA and the National Science Foundation.
Greenland is about one-fourth the size of the United States and the massive ice sheet covers about 80 percent of its surface. It holds about 20 percent of the world's ice, the equivalent of about 21 feet of global sea rise. Air temperatures over the Greenland ice sheet have increased by about 4 degrees Fahrenheit since 1991, which most scientists attribute to a build-up of greenhouse gases in the atmosphere.
A 2006 study by Wahr and Velicogna using the GRACE satellite indicated that Greenland lost roughly 164 cubic miles of ice from April 2004 to April 2006 -- more than the volume of water in Lake Erie.
The animated movie of the spread of ice loss into northwest Greenland observed by GRACE from 2003 through 2009 shows a shift in the color spectrum beginning with turquoise and ending in black over the seven-year time span. The movie was created by CU-Boulder's Wahr.
Contact
John Wahr, 303-492-8349 John.Wahr@colorado.edu
Shfaqat Abbas Khanabbas@space.dtu.dk
Isabella Velicogna, 949-824-5419
Peter Weiss, AGU, 202-777-7507
Jim Scott, CU, 303-492-3114



