Author: Outreach Office
February 1, 2012
Scientists have disagreed for many years over the precise cause for a period of cooling global temperatures that began after the Middle Ages and lasted into the late 19th century, commonly known as the Little Ice Age.
Now, a new study led by CU-Boulder Professor and Institute for Alpine and Arctic Research (INSTAAR) Fellow Gifford Miller indicates that the Little Ice Age began abruptly between A.D. 1275 and 1300, triggered by repeated, explosive volcanism and sustained by a self-perpetuating sea ice-ocean feedback system in the North Atlantic Ocean.
“This is the first time anyone has clearly identified the specific onset of the cold times marking the start of the Little Ice Age,” said Miller. “We also have provided an understandable climate feedback system that explains how this cold period could be sustained for a long period of time. If the climate system is hit again and again by cold conditions over a relatively short period—in this case, from volcanic eruptions—there appears to be a cumulative cooling effect.”
Most scientists believed the Little Ice Age was caused either by decreased summer solar radiation, erupting volcanoes that cooled the planet by ejecting shiny aerosol particles that reflected sunlight back into space, or a combination of both, said Miller.
The new study, funded by the National Science Foundation and the Icelandic Science Foundation, suggests that the onset of the Little Ice Age was caused by an unusual, 50-year-long episode of four massive tropical volcanic eruptions. Climate models used in the new study showed that the persistence of cold summers following the eruptions is best explained by a sea ice-ocean feedback system originating in the North Atlantic Ocean.
"Our simulations showed that the volcanic eruptions may have had a profound cooling effect,” says NCAR scientist Bette Otto-Bliesner, a co-author of the study. “The eruptions could have triggered a chain reaction, affecting sea ice and ocean currents in a way that lowered temperatures for centuries."
The researchers set the solar radiation at a constant level in the climate models, and Miller said the Little Ice Age likely would have occurred without decreased summer solar radiation at the time. “Estimates of the sun’s variability over time are getting smaller, it’s now thought by some scientists to have varied little more in the last millennia than during a standard 11-year solar cycle,” he said.
One of the primary questions pertaining to the Little Ice Age is how unusual the warming of Earth is today, he said. A previous study led by Miller in 2008 on Baffin Island indicated temperatures today are the warmest in at least 2,000 years.
January 25, 2012
A national research team led by the University of Colorado Boulder is embarking on a two-year, multi-pronged effort to better understand the impacts of environmental factors associated with the continuing decline of sea ice in the Arctic Ocean.
The team will use tools ranging from unmanned aircraft and satellites to ocean buoys in order to understand the characteristics and changes in Arctic sea ice, which was at 1.67 million square miles during September 2011, more than 1 million square miles below the 1979-2000 monthly average sea ice extent for September -- an area larger than Texas and California combined. Critical ocean regions north of the Alaskan coast, like the Beaufort Sea and the Canada Basin, have experienced record warming and decreased sea ice extent unprecedented in human memory, said CU-Boulder Research Professor James Maslanik, who is leading the research effort.
The team will be targeting the Beaufort Sea, considered a “marginal ice zone” where old and thick multiyear sea ice has failed to survive during the summer melt season in recent years, said Maslanik of CU-Boulder’s Colorado Center for Astrodynamics Research in CU’s engineering college. Such marginal ice zones are characterized by extensive ice loss and a strong “ice-albedo” feedback.
“Sea ice is lost when the darker ocean absorbs more sunlight in the form of heat in the summers, resulting in potentially thinner sea ice that re-forms the following winter,” Maslanik said. “This positive feedback between heat absorption by the ocean and accelerated melting becomes reinforcing in itself.” Marginal ice zones also are characterized by significant human and marine mammal activity, he said.
There was a record loss of sea ice cover over the Arctic in 2007, he said. “In some areas of the Arctic Ocean the multiyear ice rebounded, but in the Beaufort Sea we did not see that kind of multiyear ice persistence like we used to see,” said Maslanik, who also is a research professor in the aerospace engineering sciences department.
“The biggest question is whether places like the Beaufort Sea and adjacent Canada Basin have passed a ‘tipping point’ and now are essentially sub-Arctic zones where ice disappears each summer,” he said. Such ice loss could be causing fundamental changes in ocean conditions, including earlier annual blooms of phytoplankton, which are microscopic plant-like organisms that drive the marine food web.
The vast majority of climate scientists believe shrinking Arctic sea ice in recent decades is due to rising temperatures primarily caused by human activities that pump huge amounts of heat-trapping gases like carbon dioxide into the atmosphere. The new $3 million study led by Maslanik, “The Marginal Ice Zone Observations and Processes EXperiment,” or MIZOPEX, is being funded by NASA.
The team will undertake extensive airborne surface mapping using a variety of Unmanned Aircraft Systems, or UAS, comparing the results with data collected by a fleet of satellites from NASA, the National Oceanic and Atmospheric Administration and the Japanese space agency. Unlike satellites, small, unmanned aircraft can fly below the clouds, observe the same location continuously for hours and make more precise measurements of sea ice composition and sea surface temperatures. Maslanik and his CU-Boulder team previously used unmanned aircraft to assess ice conditions both in the Arctic and in Antarctica.
The MIZOPEX arsenal also will include floating buoys that measure ocean temperatures. CU-Boulder engineering faculty members Scott Palo and Dale Lawrence and their graduate students are converting miniaturized versions of dropsondes -- standard weather reconnaissance devices designed to be dropped from aircraft and capture data as they fall toward Earth -- into the buoys that will be deployed by the UAS.
The modified dropsondes, which were developed at CU-Boulder for use in Antarctica, will be combined with CU-designed miniature unmanned aircraft that will land on the ocean near sea ice floes. Such floes are critical to several species of Arctic wildlife, including polar bears, walruses and seals.
The buoys and unmanned craft will collect sea surface and subsurface temperatures to about a meter deep, while the overflying unmanned planes and satellites measure temperatures at the surface, Maslanik said. “We want to know if the warming is just at the ocean surface or if there is additional heat getting into the mixed layers of the upper ocean, either from absorbed sunlight or from ocean currents, that could be contributing to sea ice melt.”
The team plans to gather information over 24-hour cycles to determine how the ocean and ice are reacting to atmospheric changes. “Understanding what’s happening in the water is critical to forecasting what will happen to ice in the near term, as well as in the decades to come,” said MIZOPEX team scientist Betsy Weatherhead of CU-Boulder’s Cooperative Institute for Research in Environmental Sciences.
“We’ve never had the data before,” Weatherhead said. “With this new instrumentation, we’ll be able to ask questions and test theories about the drivers of ice melt.”
The MIZOPEX effort involves CU-Boulder, NASA, Fort Hays State University in Kansas, Brigham Young University, the University of Alaska-Fairbanks, NOAA, the University of Washington and Columbia University. Ball Aerospace Systems Group of Boulder also is collaborating on the project.
Other MIZOPEX project scientists from CU include Brian Argrow, Sandra Castro, Ian Crocker, William Emery, Eric Frew and Mark Tschudi. Argrow directs the CU-headquartered Research and Engineering Center for Unmanned Vehicles, a university-government-industry partnership for the development and application of unmanned vehicle systems.
For more information on MIZOPEX visit http://ccar.colorado.edu/mizopex/index.html. For more information on CU-Boulder’s Research and Engineering Center for Unmanned Vehicles visit http://recuv.colorado.edu/.
James Maslanik, 303-492-8974 James.Maslanik@colorado.edu
Betsy Weatherhead, 303-497-6653 Betsy.Weatherhead@noaa.gov
Science Explorers 2011-12: Earth System Science – Exploring Change in the Critical Zone
For more information, visit the Science Explorer's page here.
Science Explorers workshops engage teams composed of 1 teacher and 5 students (grades 5-8) in a full day of hands-on, inquiry-based science. This year's workshop, Earth System Science: Exploring Change in the Critical Zone, focuses on the complex relationships between geology, soils, climate, ice, snow, wildfires and Colorado's water supply.
During this intensive hands-on workshop, teachers and students will rotate through three interconnected workshops:
Foundations for Flow:
Students and teachers will re-create a Colorado watershed from the bedrock up, and then wear it down with constructive and destructive forces over time. They will see our geological past, experience the sedimentary rocks on the surface, and then simulate the massive uplifts and faulting that formed our mountains. Using snow, ice, summer rains and heat, they will create snowfields, glaciers, streams and rivers, to grind the mountains down to the landforms that we see today.
Fire and Water:
Using computer mapping and hands-on experiments, students and teachers will explore the relationships between ecosystems, wildfires, soils and water. They will predict fire intensity and see how wildfires impact soils, erosion and water quality. They will conduct experiments to help understand how different soils impact water flow and storage, as well as how scientists use computer models to predict the way landscapes and watersheds will change over time.
Ice, Snow and H2O:
This chilly session focuses on how weather, climate, snow and ice impact Colorado's water supply. Teachers and students will create and conduct experiments with glacial ice, and use measurements and math to understand the relationship between glaciers, snowpack and our water supply. They will compare and contrast weather data and real snow tubes to solve a mystery, and play a fun game to understand how Earth System Interactions supply year-round water to Colorado, with only the occasional flood or landslide.
For more details about the workshops, including how they address Colorado Science Standards, please contact Hester Nadel at 303-492-8640 or email@example.com.
CU at the Library presents "Climate Change: Where We Are Now and Where We Are Going"
Professor James White
Geological sciences and environmental studies
Louisville Public Library, 951 Spruce Street
January 25 7 PM
Professor James White will review the basic science behind the Earth’s climate system, discuss how humans are impacting it, and put the current climate situation into the context of natural variability. White’s research primarily focuses on how and why climate changes have occurred in the past and how carbon dioxide moves between the atmosphere, ocean, and land plants
Programs are free and open to the public.
For more information, email firstname.lastname@example.org or call 303-335-4849.
Cold Facts: Snow and Ice Family Days at the CU Museum of Natural History
Saturdays, January 7, 14, and 21
Join us at the museum as we ring in the New Year with a flurry of family activities. This January, we will be investigating the science of snow, from falling flakes to dangerous avalanches. Explore how climate change is affecting snow through hands-on activities. On January 28 we will explore climate change with a concert of environmental songs and skits created and performed by 'Jeff and Paige'. Expect original science-based music for kids, quick costume changes, plenty of audience participation and more. Ski, sled, or skate on in!
For more information: http://cumuseum.colorado.edu or email@example.com or 303-492-1666.
View the full article from the Daily Camera here.
Maxwell Boykoff's interest in how the media covers the science of climate change began as a side project nearly a decade ago.
The University of Colorado professor -- who was studying vulnerability and hurricane activity in Central America at the time -- was musing about the interaction between science and public policy when he started to wonder how the media's coverage of climate change has impacted the public's perception.
The question sent Boykoff into the archives of some of the country's most venerable publications -- the New York Times, the Washington Post, the Los Angeles Times and the Wall Street Journal -- where he discovered that many journalists' attempts to be "balanced" actually skewed their reporting on climate change.
The normal act of reporting on both sides of the story may not actually create an accurate story in the case of climate science, Boykoff concluded, since the scientific consensus is that climate change is happening and that humans are contributing to it.
Giving climate change skeptics equal space in a story may unfairly amplify their views, Boykoff found.
More than a dozen studies on climate change and the media later, Boykoff has published a book, released last week, called "Who Speaks for the Climate?: Making Sense of Media Reporting on Climate Change."
"What started as a bit of a side project, I realized was something that needed a lot more attention," said Boykoff, a researcher at CU's Center for Science and Technology Policy Research. "I ended up making that the focus of my ongoing research."
Boykoff's book takes an in-depth look into the media's coverage, which Boykoff says has improved in some ways.
"There have been lessons learned over time," he said. "But there have been lessons learned that we run the risk of having to learn again."
In particular, Boykoff is bothered by the media's tendency to conflate issues that aren't directly related into "one great global warming debate."
For example, a story about the ability of a cap-and-trade program to limit carbon emissions may end up becoming a story about whether humans contribute to climate change at all. Boykoff hopes his book will enable people to think critically about that kind of media coverage on climate change.
"For the everyday person picking up the book, it helps them really understand the processes of science, the processes of journalism and how these issues make their way onto the printed page and into a television news program," he said. "It helps them more critically engage with these kinds of issues."
Alan Townsend, director of CU's Environmental Studies Program, said that the topics tackled in Boykoff's book are an important "piece of the puzzle" to understanding how the public thinks about and responds to climate change.
"Public perception of any particular issue or event is clearly shaped by the conduit that they have for that information, which is the media," he said. "The way people are going to make decisions, the ways in which they're going to understand an issue, the way they're going to act can clearly be shaped by that."
Contact Camera Staff Writer Laura Snider at 303-473-1327 or firstname.lastname@example.org.
Looking for something to do on an upcoming BVSD day off? On Nov 11, Science Discovery is offering a free program to interested 5th-8th grade students! "Earth System Explorers" is a 3-hour workshop sponsored by the NSF-funded Boulder Creek Critical Zone Observatory (CZO).
We will be piloting a new series of engaging hands-on activities focused on water, snow, geology, climate, glaciers and fire in the Boulder Creek Watershed. Hands-on science activities will include: creating glaciers and using them to wear down mountains; building the Flatirons from the bedrock up; creating streams, rivers and valleys; exploring fire ecology, erosion and stream chemistry; discovering the secrets in snow-tubes; and more. This will be an action-packed morning of experiments, computer mapping, interactive games, hands-on science and fun!
When: Friday, November 11th, 2011, 9:00 AM -12:00 PM
Where: CU Science Discovery @ Science Learning Laboratory, 3400 Marine St (EAST CAMPUS), Boulder, CO.
This opportunity is limited to 10 students on a first-come, first-served basis. To register, please visit:
For more information, please contact Anjali Maus at 303-735-2230 or email@example.com.
INSTAAR and the Colorado Water and Energy Research Center present a two-part series on
Monday October 10th
A Geo-Engineering Perspective
Dr. Will Fleckenstein, PE
BP Adjunct Professor
Colorado School of Mines
Shale Drilling and Completions
RL-1 Room 269
Monday October 17th
An Environmental Perspective
Dr. Stephen G. Osborn
California Polytechnic University (formerly at Duke)
Methane, Water and Hydraulic Fracturing
ARC Room 269
Click here to download the flyer.
September 15, 2011
The blanket of sea ice that floats on the Arctic Ocean appears to have reached its lowest extent for 2011, the second lowest recorded since satellites began measuring it in 1979, according to the University of Colorado Boulder's National Snow and Ice Data Center.
The Arctic sea ice extent fell to 1.67 million square miles, or 4.33 million square kilometers on Sept. 9, 2011. This year's minimum of 1.67 million square miles is more than 1 million square miles below the 1979-2000 monthly average extent for September -- an area larger than Texas and California combined.
While this year's September minimum extent was greater than the all-time low in 2007, it remains significantly below the long-term average and well outside the range of natural climate variability, according to scientists involved in the analysis. Most scientists believe the shrinking Arctic sea ice is tied to warming temperatures caused by an increase in human-produced greenhouse gases pumped into Earth's atmosphere.
"Every summer that we see a very low ice extent in September sets us up for a similar situation the following year," said NSIDC Director Mark Serreze, also a professor in CU-Boulder's geography department. "The Arctic sea ice cover is so thin now compared to 30 years ago that it just can't take a hit anymore. This overall pattern of thinning ice in the Arctic in recent decades is really starting to catch up with us."
Serreze said that in 2007, the year of record low Arctic sea ice, there was a "nearly perfect" set-up of specific weather conditions. Winds pushed in more warm air over the Arctic than usual, helping to melt sea ice, and winds also pushed the floating ice chunks together into a smaller area. "It is interesting that this year, the second lowest sea ice extent ever recorded, that we didn't see that kind of weather pattern at all," he said.
The last five years have been the five lowest Arctic sea ice extents recorded since satellite measurements began in 1979, said CU-Boulder's Walt Meier, an NSIDC scientist. "The primary driver of these low sea ice conditions is rising temperatures in the Arctic, and we definitely are heading in the direction of ice-free summers," he said. "Our best estimates now indicate that may occur by about 2030 or 2040."
There still is a chance the sea ice extent could fall slightly due to changing winds or late season melt, said Meier. During the first week of October, CU-Boulder's NSIDC will issue a full analysis of the 2011 results and a comparison to previous years.
NSIDC is part of CU-Boulder's Cooperative Institute for Research in Environmental Sciences -- a joint institute of CU-Boulder and the National Oceanic and Atmospheric Administration headquartered on the CU campus -- and is funded primarily by NASA.
NSIDC's sea ice data come from the Special Sensor Microwave Imager/Sounder sensor on the Defense Meteorological Satellite Program F17 satellite using methods developed at NASA's Goddard Space Flight Center in Greenbelt, Md.
For more information and graphics visit CU-Boulder's NSIDC website at nsidc.org/arcticseaicenews/2011/091511.html.
Walt Meier, 303-492-6508
Mark Serreze, 303-492-2963
Katherine, Leitzell, 303-492-1497
from Daily Camera. View the article here.
Researchers from the University of Colorado and Kansas State University have been awarded a grant for more than $850,000 to study the impacts of climate change on prairie dogs in the Boulder area.
The massive grant -- from the Division of Environmental Biology at the National Science Foundation -- is designed to give the researchers three years in the field to try and figure out how climate change is altering prairie dog habitat and how the rodents are responding to those changes.
The study will be focused on open space lands in Boulder and Boulder County and will include testing soils, plants and prairie dog behavior. Researchers and city officials say the results will have implications for how cities manage prairie dogs in the future.
Tim Seastedt, a professor of ecology and evolutionary biology at CU and the principal investigator in the study, said global climate change has already caused changes in the growing season and the types of plant species that are found on urban open space.
One of the primary questions is whether those changes are causing prairie dogs to change their habits, including being more active during the winter -- which can lead to soil erosion after the rodents eat plants to the bare ground.
"The classical studies on prairie dogs for foraging behavior were sort of null and void" under the new climate reality, Seastedt said.
For example, prairie dogs don't hibernate, but they do tend to stay underground during the winter. Seastedt said warmer temperatures and less snow cover may change that behavior.
"This makes the argument that they're going to be up there grazing for a longer period of time," Seastedt said.
He said changes in climate and plant species could present a "variety of challenges that this keystone species has never faced."
"If these guys (prairie dogs) change their behavior, then they virtually reconstruct the system," he said.
The study also will examine the interactions between native and non-native plants, including whether new species are taking up water used by the native variety.
Seastedt said Boulder is the perfect place for a case study. After all, the city offers more protected prairie dog habitat than the massive Pawnee National Grassland on the northeastern plains.
And Boulder has a variety of non-native plant species that officials already have noticed seem to be changing the landscape.
Heather Swanson, Boulder's wildlife ecologist, said some of the changes reported in recent years include loss of topsoil and changes in plant species where prairie dogs can be found.
"Hopefully this study will actually document those changes, because right now it's just sort of anecdotal changes over time," she said.
Laurel Hartley is an assistant professor of biology at CU-Denver. She is an expert on prairie dogs and is teaming up with Seastedt on the study.
"We think we're going to find that in some places that the prairie dogs push the plant community in ways that we haven't seen before," she said.
She described the project as being "cutting edge" in terms of examining how global climate change will affect a species down the road.
Experiments will include creating cages to keep prairie dogs from grazing in certain areas and mimicking the various ways that climate change might eventually affect plants -- such as supplementing water to simulate changes in rain patterns.
"We'll know how grasslands will respond under certain scenarios," Hartley said.
She added that the results of the study likely would change the way cities such as Boulder address prairie dogs and grasslands.
"It definitely will have management implications," Hartley said.
Jesse Nippert, from Kansas State University, is a specialist in isotopic water analysis and also will be involved in the study.
Boulder Councilman Ken Wilson, who studied under Seastedt at CU, said he's eager to see the group's findings.
"I'm concerned that our management plan has not been informed by science that would look at what's happening on these fragmented parcels" of open space, Wilson said. "We've seen some impacts that are disturbing, where (prairie dogs) totally defoliate these areas. We need to understand why that's happening so that we can manage our grasslands better."
Contact Camera Staff Writer Heath Urie at 303-473-1328 or firstname.lastname@example.org.