Climate News

February 22, 2010

Mass media have been a key vehicle by which climate change contrarianism has traveled, according to Maxwell Boykoff, a University of Colorado at Boulder professor and fellow of the Cooperative Institute for Research in Environmental Sciences, or CIRES.

Boykoff, an assistant professor of environmental studies, presented his research today at the annual meeting of the American Association for the Advancement of Science in San Diego. He spoke during a panel discussion titled "Understanding Climate Change Skepticism: Its Sources and Strategies."

Boykoff's segment was titled "Exaggerating Denialism: Media Representations of Outlier Views on Climate Change" and discussed prominent pitfalls.

"One problem occurs when outlier viewpoints are not individually evaluated in context," said Boykoff. "A variety of influences and perspectives typically have been collapsed by mass media into one general category of skepticism. This has been detrimental both in terms of dismissing legitimate critiques of climate science or policy, as well as amplifying extreme and tenuous claims."

Such claims are amplified when traditional news media position noncredible contrarian sources against those with scientific data, in a failed effort to represent opposing sides, said Boykoff.

Another issue in mass media is the tendency to flatly report on both the claims of contrarians, as well as the accusations made about their claims and motives, he said. The ensuing finger-pointing plays into the conflict, drama and personalized stories that drive news. It also distracts attention from critical institutional and societal challenges regarding carbon consumption that calls citizen behaviors, actions and decisions to account.

"Reducing climate science and policy considerations to a tit-for-tat between dueling personalities comes at the expense of appraising fundamental challenges regarding the necessary de-carbonization of industry and society," said Boykoff.

Among various and ongoing research strategies, Boykoff -- in partnership with Maria Mansfield from Exeter University and the University of Oxford -- has tracked climate change coverage in 50 newspapers in 20 countries and six continents since 2004. Boykoff also has looked at how climate science and policy find meaning and traction in people's everyday lives through work in the United States, United Kingdom and India.

Speakers Stephen Schneider from Stanford University; Naomi Oreskes from the University of California, San Diego; William Freudenburg from the University of California, Santa Barbara; and Riley Dunlap from Oklahoma State University joined Boykoff on the panel.

For more information on Boykoff's research visit sciencepolicy.colorado.edu/about_us/meet_us/max_boykoff/

Contact
Maxwell Boykoff, 303-735-6316

Boykoff@Colorado.edu

Elizabeth Lock, CU News Services, 303-492-3117
Elizabeth.Lock@Colorado.edu

Creative Financing Tips for Professional Education

Professionals who are interested in training and development face a conundrum. When they are working full-time, possibly with the additional pressure of supporting their families, finding time to fit in coursework is a challenge.  Finding the financial means to pay for training can also be difficult.  For workers who are between jobs, being able to pay for training may become an even greater concern.

Although finding unused time is still a chimera for many of us, finding a way to pay for coursework may be an easier question to tackle.  While federal loans are reserved for students enrolled in degree programs, other options do exist for those who seek help to pay for non-degree programs, such as professional development and training certificates.

Federal and State Workforce Funding

Some workers may be eligible for free financing for their chosen training program through federal and state workforce funding. This avenue is particularly attractive for workers who may be between jobs and who want to make a career shift. The major benefit of financing your training this way is that it is usually 100% paid for. However, not every worker will qualify, and the application and proposal process takes time and effort to complete.

So where does workforce funding come from? The 1998 Workforce Investment Act addressed the changing needs surrounding training, adult education, federal employment, and vocational rehabilitation programs. In Colorado, for example, county workforce centers provide free services for workers in a one-stop-shop environment:  training, job listings, Internet access, career counseling, and other services. They focus on helping people from varied backgrounds and occupations.

Employment advisors at Workforce Boulder County helped Adam Cahn, a student enrolled in both the Building & Energy Certificate and the Sustainability Management Certificate. While attending an unemployment seminar, Cahn heard a fellow participant talk about her training, which she was able to finance with Workforce Investment Act funding.

Cahn said, “I was unemployed and had been trying to make a career shift. I googled the Workforce Investment Act and realized that I might be able to get funding to complete the Sustainable Practices coursework I’d already started. I knew where my gaps were and how I could fill them with the Sustainable Practices certificates; the workforce funding will help me get there.”

If you are a worker interested in how the Workforce Investment Act might be able to help you with your career needs, where should you begin? Cahn suggests you contact your county or state Workforce Center for help.  Center Employment advisors will schedule you to attend a Workforce Investment Information Meeting, if appropriate, and help you submit a Training Request Proposal to the Workforce Investment Act Scholarship Committee.

Lee is another Sustainable Practices student who is receiving workforce development funding, in this case through Douglas County. She worked to get Sustainable Practices approved with the Colorado Workforce Center training navigator.  She said, “I am on the older side; I have good credentials but they’re thirty years old. The workforce center told me I needed to update them. Workforce is a good program; it helps people get back into the job market.”

For more information on Colorado’s Workforce Centers, visit http://www.coworkforce.com/emp/WFCs.asp.

Financing Through Your Local Bank

During times of unemployment or underemployment, some of us may be tempted to turn to our credit cards to fill the gap.  However, the drawback is obvious:  credit cards demand higher interest than most loans; you don’t come away with new skills or applicable experience; and credit card debt can be difficult to pay down once financial difficulties let up.

However, there is an alternative to using credit cards to finance debt. Some workers can finance professional development and training through their local bank. To find out about alternative student loan programs, start with the educational institution where you are seeking training.  For example, Rosanne Romano, a financial aid officer here at the CU-Boulder Division of Continuing Education and Professional Studies, has helped many students find creative bank financing for education.

Romano said, “Bank loans are tied to a specific academic term in which a student is enrolled.  So, if a student enrolls for summer and fall term, the university would certify the loan to cover the student’s expenses during that time frame—including tuition, student fees, and living expenses like room and board.”

Because they are tied to a specific term and are flexible in the types of expenses they can be used for, bank loans can be a great way to finance education and professional development. This is particularly true for workers who are between jobs or who anticipate increasing their earnings after completing their education.

A Note about Employer Financing

For workers who are employed but who would like financial support to receive training, consider asking your employer to pay for all or part of your training.  Many companies stand behind their employees’ need to grow professionally; however, it can help if you make a business case for your training.

Janice  Godard, an employee at Avaya in Highlands Ranch, Colorado, is earning her Sustainable Practices certificate with the financial support of her company.  Godard said, “I think it’s important to go to your company and make the argument that this training that you want to get will benefit them somehow—for example, that they’ll become more energy efficient.”

Also plan to work with the education program that you are considering enrolling with; training staff can tell you about paid-in-full discounts or help with documenting the potential benefits to your employer.

Finally, consider that professional development often equates with attending annual professional conferences.  While such events can be valuable, attendance may not give you a new credential the way that focused training or a professional certificate might. This can be a selling point when you make the case to substitute annual conference attendance with employer-paid training.

Special Scholarships and Work-Exchange Arrangements

In addition to the avenues above, don’t forget to explore financial support offered through nonprofit foundations or even through the educational institution you plan to attend. Educational institutions or training centers sometimes offer special scholarships to applicants. An example of this is our Sustainability Management Certificate Scholarship, a one-time scholarship to award 100% tuition to five recipients (learn more and apply: PDF WORD).

Geoffrey Rubinstein, Director of Sustainability Management, said, “We are passionate about the need to educate a new cadre of sustainability experts, and we thought a scholarship would be a great way to show how serious we are about making this program accessible.”

Some institutions may also occasionally offer free training in exchange for program support.  For example, a training center may give you a free class or a tuition discount for work in their marketing or communications department.

In Conclusion

Creative financing for training does exist.  The key is to explore as many different ways of potential funding as you can.  Take advantage of the financial experts available to you through educational institutions, your state or local government, your local bank, and other avenues that are there to help. And remember to view the time and money that you are putting into your training is an investment in you, your future, and that of your community.

Lee said, “With the state of the economy the way it is right now, it’s hard for some people to get a job. Getting professional training is important. Sustainable Practices, in particular, will help get people into the new energy economy.”

December 10, 2009

It's no secret that the emissions leaving a car tailpipe or factory smokestack affect climate and air quality. Even trees release chemicals that influence the atmosphere. But until now, scientists have struggled to know where these organic molecules go and what happens to them once they leave their source, leading to models for predicting climate and air quality that are incomplete or less than accurate.

A major collaborative effort of more than 60 scientists led by Jose-Luis Jimenez, an associate professor of chemistry at the University of Colorado at Boulder, has discovered common ground in the jumble of organic material floating through the skies. The finding presents a workable solution that will improve the speed and accuracy of prediction models used to understand how these aerosols affect climate and human health, said Jimenez, also a fellow of the Cooperative Institute for Research in Environmental Sciences, or CIRES.

"We're providing a key piece of machinery that is needed to make accurate predictions of air quality and climate and that is also relatively simple and practical to use," said Jimenez, lead author of the study that appears in the Dec. 11 issue of Science. CIRES is a joint institute of CU and the National Oceanic and Atmospheric Administration.

Organic compounds coat airborne particles like a lacquer of spray paint and make up as much as 90 percent of all fine particle mass aloft in the atmosphere. These particles influence cloud formation and subsequent rainfall. They also affect human health and can lead to illnesses like asthma, heart disease and lung cancer.

But so far only about 10 to 30 percent of the thousands of individual compounds have been identified, and past research has focused on following specific molecules with the idea that these compounds remain relatively static in nature once they enter the atmosphere. Recent discoveries show that the life cycle of these compounds is much more complex, with organic molecules reacting many times over in many different ways. Attempts by atmospheric scientists to track this life cycle often leave researchers with a vast array of divergent paths to follow.

To find some order in this chaos, Jimenez and his colleagues began looking at organic particles with a more holistic mindset. Through a series of field observations and lab experiments conducted all over the world, they found that organic matter ultimately tends to evolve toward a similar end, regardless of the source or where the matter occurs in the atmosphere

"What surprised us is how similar the organic matter looked as we went from the heart of Mexico City to an island in Japan to a forest in Finland or a mountain in the Swiss Alps," said Jimenez.

"The atmosphere acts like Dan Aykroyd's Bass-O-Matic, making similar-looking goop almost no matter what you start with," said Neil Donahue, a study co-author with Carnegie Mellon University.

The study found that this particle soup can be boiled down into a few measurable characteristics, such as the oxygen-to-carbon ratio, which are key variables for predicting climate and air quality.

"Using a novel aerosol mass spectrometer, we found that the atmosphere blurs the differences between aerosols emitted by different sources relatively quickly," said Manjula Canagaratna, a co-author from Aerodyne Research in Boston. "This is potentially a very important simplification, which is key to improving air quality and climate models."

Of importance in the study was the creation of a chemical "map" by Donahue. The map provides some of the first clear visualization of how these organic aerosols change once they become a part of the particle soup.

The map tracks two key properties -- volatility, or the tendency to evaporate, and the oxygen-to-carbon ratio -- that evolve as organics make their way through the atmosphere. This ratio is important because it is an indicator of how much the organic matter is gaining oxygen and building up on particles floating in the air, a process that influences air quality and climate. "And as a bonus, this road map has the promise to let people predict the ability of the organics to participate in cloud formation," Donahue said.

"These results allow us to do a better job in predicting future climate and air quality," Jimenez said. "And we need good predictions in order to be able to do the right thing."

The research study was funded with grants from the National Science Foundation, the U.S. Department of Energy and the U.S. Environmental Protection Agency. It included scientists from more than 30 institutes, including Carnegie Mellon University, Aerodyne Research Inc., and international collaborators from England, Switzerland, China, Japan, Mexico, Germany, Sweden and Finland.

Contact

Jose-Luis Jimenez, 303-492-3557

jose.jimenez@colorado.edu

Morgan Heim, CIRES, 303-492-6289
morgan.heim@cires.colorado.edu

December 14, 2009

A new study led by the University of Colorado at Boulder indicates part of the northern Alaska coastline is eroding by up to 45 feet annually due to declining sea ice, warming seawater and increased wave activity. Image courtesy Robert S. Anderson, University of Colorado

The northern coastline of Alaska midway between Point Barrow and Prudhoe Bay is eroding by up to one-third the length of a football field annually because of a "triple whammy" of declining sea ice, warming seawater and increased wave activity, according to new study led by the University of Colorado at Boulder.

The conditions have led to the steady retreat of 30 to 45 feet a year of the 12-foot-high bluffs -- frozen blocks of silt and peat containing 50 to 80 percent ice -- which are toppled into the Beaufort Sea during the summer months by a combination of large waves pounding the shoreline and warm seawater melting the base of the bluffs, said CU-Boulder Associate Professor Robert Anderson, a co-author on the study. Once the blocks have fallen, the coastal seawater melts them in a matter of days, sweeping the silty material out to sea.

Anderson, along with collaborators Cameron Wobus of Stratus Consulting and Irina Overeem of CU's Institute of Arctic and Alpine Research, or INSTAAR, each presented results from components of their study at the annual meeting of the American Geophysical Union in San Francisco held Dec. 14-18.

The problem is caused by several factors, including increased erosion along the Alaskan coastline due to longer ice-free summer conditions and warmer seawater bathing the coast, Anderson said. The third potential factor is that the longer the sea ice is detached from the coastline, the further out to sea the sea-ice edge will be. This open-ocean distance between the sea ice and the shore, known as the "fetch," increases both the energy of waves crashing into the coast and the height to which warm seawater can come into contact with the frozen bluffs, said Anderson.

"What we are seeing now is a triple whammy effect," said Anderson. "Since the summer Arctic sea ice cover continues to decline and Arctic air and sea temperatures continue to rise, we really don't see any prospect for this process ending."

In addition to Wobus and Overeem, co-authors on the studies include Gary Clow and Frank Urban of the U.S. Geological Survey in Lakewood, Colo., and Tim Stanton of the Naval Postgraduate School in Monterey, Calif.

The shoreline bluffs are made up of contiguous, polygon-shaped blocks, primarily made of permafrost and each roughly 70 to 100 feet across, he said. Ice "wedges" created by seeping summer surface water that annually freezes and thaws are driven deeper and deeper into the cracks between individual blocks each year. The blocks closest to the sea are undermined as warm seawater melts their base, and eventually split apart from neighboring blocks and topple during stormy conditions, said Anderson.

The researchers used a variety of instruments and methods in the study to examine the dynamic transition between the land and the sea, including time-lapse photography of shoreline erosion, global positioning systems (GPS), meteorological measurements including temperature and wind speed, and sediment analyses of the coastal bluffs. Offshore measurements included sea-ice distribution, ocean floor depth, sea-surface temperatures and wave dynamics, said Anderson, also a fellow at INSTAAR.

The time-lapse images were taken with four tripod mounted "game cameras" often used by hunters and wildlife biologists and which were set up parallel to the shoreline. The cameras snapped pictures every six hours during the 24-hour summer daylight months to track the effects of the waves on the coastline, said Anderson.

"Once one of these blocks topples, the process continues on to the next block," Anderson said. "These images are very powerful, because they pick up activity during severe storms when we aren't there to watch." The images also illustrate the steady melting along the water's edge that helps to undermine the bluffs even in the absence of storm activity.

The research team also deployed four submerged ocean buoys attached to metal sleds with sensors to measure the wave activity at different depths in the shallow coastal waters, comparing wave power with the shoreline fetch. The team attached temperature sensors to the buoy mooring lines to monitor seawater temperatures, which have been warming in recent summers due to increased solar radiation, he said.

When the sea ice is further from the shore, currents from the Beaufort and Chukchi seas transport warmer water to the coastline, said Anderson. While the temperature hovers around 45 degrees during the summer months, the shallow coastal water warmed to as much as 59 degrees during the 2007 field season -- the same year the largest loss of summer Arctic sea was recorded, he said.

As the ice wedges cut down through the polygon blocks, the surface soil above them -- which thaws each summer -- is pushed up slightly, forming small ridges that eventually surround each polygon, said Anderson. Small ponds form above individual polygons during the summer months as the surface ice and snow melts, providing habitat for migrating birds that feed and breed along the Beaufort Sea coastline.

"This is an important habitat for birds and other wildlife," said Anderson. "One of the concerns we have is that some larger ponds and lakes located slightly further inland may begin draining into the sea as the shoreline continues to recede."

While there are no towns adjacent to the specific study area, coastal erosion threatens abandoned military and petroleum infrastructure, he said. Coastal erosion occurs at similar sites elsewhere along Alaska's coastline. Bank stabilization measures using sandbags, for example, have been undertaken at the Alaskan town of Kaktovik on the Beaufort Sea in an attempt to slow the problem.

According to a 2009 CU-Boulder study, Arctic sea ice during the annual September minimum is now declining at a rate of 11.2 percent per decade. Only 19 percent of the ice cover was more than two years old -- the least ever recorded in the satellite record and far below the 1981-2000 summer average of 48 percent.
To view a video featuring Anderson and time-lapse photography of the eroding coastline visit www.colorado.edu/news.

Contact

Robert Anderson, 303-735-8169

Robert.S.Anderson@colorado.edu

Jim Scott, 303-492-3114

Jim.scott@colorado.edu
 

January 7, 2010

A surprising new CU-Boulder study indicates subalpine forests in the West will soak up less carbon dioxide as the climate warms and the growing seasons lengthen. Image courtesy Steve Miller, CIRES.

Contrary to conventional belief, as the climate warms and growing seasons lengthen subalpine forests are likely to soak up less carbon dioxide, according to a new University of Colorado at Boulder study.

As a result, more of the greenhouse gas will be left to concentrate in the atmosphere.

"Our findings contradict studies of other ecosystems that conclude longer growing seasons actually increase plant carbon uptake," said Jia Hu, who conducted the research as a graduate student in CU-Boulder's ecology and evolutionary biology department in conjunction with the university's Cooperative Institute for Research in Environmental Sciences, or CIRES.

The study will be published in the February edition of the journal Global Change Biology.

Working with ecology and evolutionary biology professor and CIRES Fellow Russell Monson, Hu found that while smaller spring snowpack tended to advance the onset of spring and extend the growing season, it also reduced the amount of water available to forests later in the summer and fall. The water-stressed trees were then less effective in converting CO2 into biomass. Summer rains were unable to make up the difference, Hu said.

"Snow is much more effective than rain in delivering water to these forests," said Monson. "If a warmer climate brings more rain, this won't offset the carbon uptake potential being lost due to declining snowpacks."

Drier trees also are more susceptible to beetle infestations and wildfires, Monson said.

The researchers found that even as late in the season as September and October, 60 percent of the water in stems and needles collected from subalpine trees along Colorado's Front Range could be traced back to spring snowmelt. They were able to distinguish between spring snow and summer rain in plant matter by analyzing slight variations in hydrogen and oxygen atoms in the water molecules.

The results suggest subalpine trees like lodgepole pine, subalpine fir and Englemann spruce depend largely on snowmelt, not just at the beginning of the summer, but throughout the growing season, according to the researchers.

"As snowmelt in these high-elevation forests is predicted to decline, the rate of carbon uptake will likely follow suit," said Hu.

Subalpine forests currently make up an estimated 70 percent of the western United States' carbon sink, or storage area. Their geographic range includes much of the Rocky Mountains, Sierra Nevada and high-elevation areas of the Pacific Northwest.

Study co-authors included David Moore of King's College London and Sean Burns of the National Center for Atmospheric Research and CU-Boulder.

CIRES is a joint institute of CU-Boulder and the National Oceanic and Atmospheric Administration. For more information about CIRES visit cires.colorado.edu.

Contact 

Jia Hu, 303-492-5796

Jia.Hu@colorado.edu

Russell Monson, 303-492-6319

Monsonr@colorado.edu

Morgan Heim, 303-492-6289

morgan.heim@cires.colorado.edu

University of Colorado Researcher Vasilii Petrenko explains the science of studying carbon dioxide on the Greenland Ice sheet.

Nov. 19: Green Ice Core: An international team of scientists are drilling deep into the past to learn what our future may hold. NBC's Anne Thompson reports.

An analysis of sediment cores indicates that biological and chemical changes occurring at a remote Arctic lake are unprecedented over the past 200,000 years and likely are the result of human-caused climate change, according to a new study led by the University of Colorado at Boulder.

While environmental changes at the lake over the past millennia have been shown to be tightly linked with natural causes of climate change -- like periodic, well-understood wobbles in Earth's orbit -- changes seen in the sediment cores since about 1950 indicate expected climate cooling is being overridden by human activity like greenhouse gas emissions. The research team reconstructed past climate and environmental changes at the lake on Baffin Island using indicators that included algae, fossil insects and geochemistry preserved in sediment cores that extend back 200,000 years.

"The past few decades have been unique in the past 200,000 years in terms of the changes we see in the biology and chemistry recorded in the cores," said lead study author Yarrow Axford of CU-Boulder's Institute of Arctic and Alpine Research. "We see clear evidence for warming in one of the most remote places on Earth at a time when the Arctic should be cooling because of natural processes."

The study was published Oct. 19 in the Proceedings of the National Academy of Sciences. The study included researchers from CU-Boulder, the State University of New York's University at Buffalo, the University of Alberta, the University of Massachusetts and Queen's University in Kingston, Ontario.

The sediment cores were extracted from the bottom of a roughly 100-acre, 30-foot-deep lake near the village of Clyde River on the east coast of Baffin Island, which is several hundred miles west of Greenland. The lake sediment cores go back in time 80,000 years beyond the oldest reliable ice cores from Greenland and capture the environmental conditions of two previous ice ages and three interglacial periods.

The sediment cores showed that several types of mosquito-like midges that flourish in very cold climates have been abundant at the lake for the past several thousand years. But the cold-adapted midge species abruptly began declining in about 1950, matching their lowest abundances of the last 200,000 years. Two of the midge species adapted to the coldest temperatures have completely disappeared from the lake region, said Axford.

In addition, a species of diatom, a lake algae that was relatively rare at the site before the 20th century, has undergone unprecedented increases in recent decades, possibly in response to declining ice cover on the Baffin Island lake.

"Our results show that the human footprint is overpowering long-standing natural processes even in remote Arctic regions," said co-author John Smol of Queen's University. "This historical record shows that we are dramatically affecting the ecosystems on which we depend."

The ancient lake sediment cores are the oldest ever recovered from glaciated parts of Canada or Greenland. Massive ice sheets during ice ages generally scour the underlying bedrock and remove previous sediments.

"What is unique about these sediment cores is that even though glaciers covered this lake, for various reasons they did not erode it," said study co-author Jason Briner of the University at Buffalo. The result is that we have a really long sequence of sediment that has survived Arctic glaciations."

Axford emphasized the multiyear research project required expertise from each of the five institutions involved in the PNAS study. "This was a team effort all the way around, and each of the institutions has a unique set of skills that allowed us to carry out this study," she said. "We needed people who understood algae, insects, glaciers and geochemistry, not to mention how to drive snowmobiles and extract the cores."

The study was funded by the National Science Foundation, the Natural Sciences and Engineering Research Council of Canada and the Geological Society of America.

A study published in Science magazine last month that involved CU-Boulder researchers and reconstructed past temperatures in the Arctic using ice cores, tree rings and lake sediments concluded that recent warming around the Arctic is overriding a cooling trend caused by Earth's periodic wobble. Earth is now about 0.6 million miles further from the sun during the Northern Hemisphere summer solstice than it was in 1 B.C. -- a trend that has caused overall cooling in the Arctic until recently.

INSTAAR researcher and CU-Boulder geological sciences Professor Gifford Miller was a co-author on both the PNAS study and the recent Science study.

Contact:
Yarrow Axford, 303-492-7641
Yarrow.axford@colorado.edu

Gifford Miller, 303-492-6962
gmiller@colorado.edu

Jim Scott, 303-492-3114
Jim.scott@colorado.edu

Despite a slight recovery in summer Arctic sea ice in 2009 from record-setting low years in 2007 and 2008, the sea ice extent remains significantly below previous years and remains on a trend leading toward ice-free Arctic summers, according to the University of Colorado at Boulder's National Snow and Ice Data Center.

According to the CU-Boulder center, the 2009 minimum sea ice extent was the third lowest since satellite record-keeping began in 1979. The past five years have seen the five lowest Arctic sea ice extents ever recorded.

"It's nice to see a little recovery over the past couple of years, but there's no reason to think that we're headed back to conditions seen in the 1970s," said NSIDC Director Mark Serreze, also a professor in CU-Boulder's geography department. "We still expect to see ice-free summers sometime in the next few decades."

The average ice extent during September, a standard measurement for climate studies, was 2.07 million square miles (5.36 million square kilometers). This was 409,000 square miles (1.06 million square kilometers) greater than the record low for the month in 2007, and 266,000 square miles (690,000 square kilometers) greater than the second-lowest extent recorded in September 2008.

The 2009 Arctic sea ice extent was still 649,000 square miles (1.68 square kilometers) below the 1979-2000 September average, according to the report. Arctic sea ice in September is now declining at a rate of 11.2 percent per decade and in the winter months by about 3 percent per decade. The consensus of scientists is that the shrinking Arctic sea ice is tied to warming temperatures caused by an increase in human-produced greenhouse gases being pumped into Earth's atmosphere, as reported by the Intergovernmental Panel on Climate Change.

Sea surface temperatures in the Arctic this season remained higher than normal, but slightly lower than the past two years, according to data from University of Washington Senior Oceanographer Mike Steele. The cooler conditions, which resulted largely from cloudy skies during late summer, slowed ice loss compared to the past two years. In addition, atmospheric patterns in August and September helped to spread out the ice pack, keeping extent higher.

The September 2009 ice cover remained thin, leaving it vulnerable to melt in coming summers, according to the CU-Boulder report. At the end of the summer, younger, thinner ice less than one year in age accounted for 49 percent of the ice cover. Second- year ice made up 32 percent of the ice cover, compared to 21 percent in 2007 and 9 percent in 2008.

Only 19 percent of the ice cover was over two years old -- the least ever recorded in the satellite record and far below the 1981-2000 summer average of 48 percent, according to the CU-Boulder report. Measurements of sea ice thickness by satellites are used to determine the age of the ice.

Earlier this summer, NASA researcher Ron Kwok and colleagues from the University of Washington in Seattle published satellite data showing that ice thickness declined by 2.2 feet between 2004 and 2008.

"We've preserved a fair amount of first-year ice and second-year ice after this summer compared to the past couple of years," said NSIDC scientist Walt Meier of CU-Boulder's Cooperative Institute for Research in Environmental Sciences. "If this ice remains in the Arctic thorough the winter, it will thicken, which gives some hope of stabilizing the ice cover over the next few years. However, the ice is still much younger and thinner than it was in the 1980s, leaving it vulnerable to melt during the summer."

Arctic sea ice follows an annual cycle of melting through the warm summer months and refreezing in the winter. Sea ice reflects sunlight, keeping the Arctic region cool and moderating global climate temperatures.

While Arctic sea ice extent varies from year to year because of changing atmospheric conditions, ice extent has shown a dramatic overall decline over the past 30 years.

"A lot of people are going to look at the graph of ice extent and think that we've turned the corner on climate change," said NSIDC Lead Scientist Ted Scambos of CU-Boulder's CIRES. "But the underlying conditions are still very worrisome."

NSIDC is part of CIRES and is funded primarily by NASA.

For more information, including charts and graphs of Arctic sea ice, visit nsidc.org/arcticseaicenews/.

Contact
Katherine Leitzell, 303-492-1497
; leitzell@nsidc.org


Jim Scott, CU News Services, 303-492-3114
; Jim.scott@colorado.edu