Climate News

GreenTeacher.com offers free, one hour webinars led by innovative and experienced educators. Topics cover a range of environmental issues such as sustainability, inclusive science education, and energy education. Each session features a 20-30 minute presentation, and 30-40 minutes for you to ask a question of the presenter. Previous webinars are available at http://greenteacher.com/webinararchive. There has been a great response to the first four environmental webinars offered. If you missed them, here is information on the four upcoming webinars.

To view the current schedule, please visit http://greenteacher.com/webinars.

We'd like to inform you about a potentially useful video resource for your classroom titled, "Changing Planet." It is funded and carried out by NSF's Office of Legislative and Public Affairs, in partnership with NBC Learn.

The project  includes 13 videos with associated lesson plans, being posted online over 13 weeks.  

Videos:  Changing Planet

Lesson Plans: Windows to the Universe

These videos could be useful to screen in your classroom, and even come with lesson plans about coral reefs, warming in the Arctic, drought, and more.

NSF will be hosting three town halls with NBC TV personalities at US universities: Yale in January with Tom Brokaw, George Washington University in April, and an Arizona university in August. These panel discussions, at which the high school and college students making up the live audience can ask questions, focus on various aspects of climate change and are taped for later airing on TV. The Yale event focused on the impacts of climate change on lives; GWU will focus on clean energy; and Arizona on water resources.

Rocky Mountain Middle School Math and Science Partnership presents the 2011 Research Experience for Teachers (RET) Program


JUNE 20 - July 22 | Monday - Friday

Middle level math and/or science teachers are encouraged to apply for these intense professional development content courses. Selected teachers will be part of a 5-week research experience where they will work along side of their peers and professionals in their field conducting research and analyzing data.

Participating teachers will raise their level of understanding of relevant mathematics by engaging important topics in a “hands on” way in the workshop. They will be able to transform what they have learned into new curricular materials that will improve the mathematics and science capabilities of their students and hopefully stimulate students to consider careers in science, technology, engineering or mathematics.

A $5,000 stipend will be rewarded to participants who successfully complete the program. Graduate credit hours (1-6) are available for these programs.

Participants will:
1) Participate in a six hour, five day a week, hands on workshop.
2) Meet weekly with RET teachers studying other topics in the mathematical sciences
3) Meet weekly with RET teachers from biology, chemistry, and physics in a interdisciplinary math/science consortium
4) Develop at least one inquiry based module for use in the classroom in the upcoming academic year

Anyone can apply for these programs. However, priority will be given to those who are already active participants in the RMMSMSP and have taken courses through the partnership before. Previous RET participants are encouraged to reapply, however, priority will be given to those in the RMMSMSP who have not yet done one of these experiences. Applications will be taken until all spaces are filled.

Please see our website for more information or to apply for the program.
http://rmmsmsp.ucdenver.edu/RET.html

Exploring Climate Connections between the Global Oceans and Colorado's Weather, Ecosystems & Economy

COSEE West - Colorado Collaborative presents a teacher professional development course spring and summer, 2011

When:
Saturday, April 9th, from 9am to 12 pm at the University of Colorado***
Saturday, May 7th, from 9am to 12 pm at the University of Colorado***
June 27 – July 1, from 8:30 am to 4:30 pm daily at Boulder High School

***Teachers can attend these workshops via videoconferencing.  Please contact Lesley Smith if you are interested in participating via videoconference for the two spring sessions.

Participation is limited to 25 middle and high school teachers who wish to teach about the connections between the global oceans, weather, climate and the local economy. You will also make connections to five Southern California teachers, who will be participating in our exchange program.

Information and application available online at: http://cires.colorado.edu/education/outreach/cosee/

Application deadline: Monday, March 21, 2011 at 5pm

This year’s focus will be Water in The West, and we will explore the link between the global oceans and water resources in the Western U.S.  Colorado’s State Climatologist, along with members of the Western Water Assessment and CU’s law school, will be featured speakers.

*   Scientists will present talks on their cutting edge research
*   Lessons that can be used in the classroom will be tied to the themes (both in science and computer labs)
*   The nature and process of science will be explored

Participants will be paid a $250 stipend upon completion of the full course.  Graduate credit will be available through the University of Colorado and paid for by participants ($60/credit). Two semester hours of credit will be awarded and one additional credit can be earned during 2011/2012 for completion of classroom materials.

For those traveling greater than 60 miles one way, room and board will be provided at no cost. Participants will share rooms.

Colorado teachers can apply for the teacher exchange program to attend COSEE West’s Ocean Observatories Workshop August 1-5, 2011.  All travel expenses are covered.  For more information visit http://www.usc.edu/org/cosee-west/workshops.html
­­­
Contact
For questions about this course, contact Lesley Smith, Program Director
Lesley.Smith@colorado.edu

303-735-1750


Supported by a grant from the National Science Foundation.

February 16, 2011

Up to two-thirds of Earth's permafrost likely will disappear by 2200 as a result of warming temperatures, unleashing vast quantities of carbon into the atmosphere, says a new study by the University of Colorado Boulder's Cooperative Institute for Research in Environmental Sciences.

The carbon resides in permanently frozen ground that is beginning to thaw in high latitudes from warming temperatures, which will impact not only the climate but also international strategies to reduce fossil fuel emissions, said CU-Boulder's Kevin Schaefer, lead study author. "If we want to hit a target carbon dioxide concentration, then we have to reduce fossil fuel emissions that much lower than previously thought to account for this additional carbon from the permafrost," he said. "Otherwise we will end up with a warmer Earth than we want."

The escaping carbon comes from plant material, primarily roots trapped and frozen in soil during the last glacial period that ended roughly 12,000 years ago, he said. Schaefer, a research associate at CU-Boulder's National Snow and Ice Data Center, an arm of CIRES, likened the mechanism to storing broccoli in a home freezer. "As long as it stays frozen, it stays stable for many years," he said. "But if you take it out of the freezer it will thaw out and decay."

While other studies have shown carbon has begun to leak out of permafrost in Alaska and Siberia, the study by Schaefer and his colleagues is the first to make actual estimates of future carbon release from permafrost. "This gives us a starting point, and something more solid to work from in future studies," he said. "We now have some estimated numbers and dates to work with."

The new study was published online Feb. 14 in the scientific journal Tellus. Co-authors include CIRES Fellow and Senior Research Scientist Tingjun Zhang from NSIDC, Lori Bruhwiler of the National Oceanic and Atmospheric Administration and Andrew Barrett from NSIDC. Funding for the project came from NASA, NOAA and the National Science Foundation.

Schaefer and his team ran multiple Arctic simulations assuming different rates of temperature increases to forecast how much carbon may be released globally from permafrost in the next two centuries. They estimate a release of roughly 190 billion tons of carbon, most of it in the next 100 years. The team used Intergovernmental Panel on Climate Change scenarios and land-surface models for the study.

"The amount we expect to be released by permafrost is equivalent to half of the amount of carbon released since the dawn of the Industrial Age," said Schaefer. The amount of carbon predicted for release between now and 2200 is about one-fifth of the total amount of carbon in the atmosphere today, according to the study.

While there were about 280 parts per million of CO2 in Earth's atmosphere prior to the Industrial Age beginning about 1820, there are more than 380 parts per million of carbon now in the atmosphere and the figure is rising. The increase, equivalent to about 435 billion tons of carbon, resulted primarily from human activities like the burning of fossil fuels and deforestation.

Using data from all climate simulations, the team estimated that about 30 to 60 percent of Earth's permafrost will disappear by 2200. The study took into account all of the permanently frozen ground at high latitudes around the globe.

The consensus of the vast majority of climate scientists is that the buildup of CO2 and other greenhouse gases in Earth's atmosphere is the primary reason for increasingly warm temperatures on Earth. According to NOAA, 2010 was tied for the hottest year on record. The hottest decade on record occurred from 2000 to 2010.

Greater reductions in fossil fuel emissions to account for carbon released by the permafrost will be a daunting global challenge, Schaefer said. "The problem is getting more and more difficult all the time," he said. "It is hard enough to reduce the emissions in any case, but now we have to reduce emissions even more. We think it is important to get that message out now."

CIRES is a joint institute of CU-Boulder and NOAA.

To view a short video of Schaefer talking about thawing permafrost visit www.colorado.edu/news and click on the story headline.

Contact

Kevin Schaefer, 303-492-8869
Kevin.Schaefer@colorado.edu

Katherine Leitzell, NSIDC, 202-492-1497
Leitzell@nsidc.org

January 27, 2011

The temperatures of North Atlantic Ocean water flowing north into the Arctic Ocean adjacent to Greenland -- the warmest water in at least 2,000 years -- are likely related to the amplification of global warming in the Arctic, says a new international study involving the University of Colorado Boulder.

Led by Robert Spielhagen of the Academy of Sciences, Humanities and Literature in Mainz, Germany, the study showed that water from the Fram Strait that runs between Greenland and Svalbard -- an archipelago constituting the northernmost part of Norway -- has warmed roughly 3.5 degrees Fahrenheit in the past century. The Fram Strait water temperatures today are about 2.5 degrees F warmer than during the Medieval Warm Period, which heated the North Atlantic from roughly 900 to 1300 and affected the climate in Northern Europe and northern North America.

The team believes that the rapid warming of the Arctic and recent decrease in Arctic sea ice extent are tied to the enhanced heat transfer from the North Atlantic Ocean, said Spielhagen. According to CU-Boulder's National Snow and Ice Data Center, the total loss of Arctic sea ice extent from 1979 to 2009 was an area larger than the state of Alaska, and some scientists there believe the Arctic will become ice-free during the summers within the next several decades.

"Such a warming of the Atlantic water in the Fram Strait is significantly different from all climate variations in the last 2,000 years," said Spielhagen, also of the Leibniz Institute of Marine Sciences in Keil, Germany.

According to study co-author Thomas Marchitto, a fellow at CU-Boulder's Institute of Arctic and Alpine Research, the new observations are crucial for putting the current warming trend of the North Atlantic in the proper context.

"We know that the Arctic is the most sensitive region on the Earth when it comes to warming, but there has been some question about how unusual the current Arctic warming is compared to the natural variability of the last thousand years," said Marchitto, also an associate professor in CU-Boulder's geological sciences department. "We found that modern Fram Strait water temperatures are well outside the natural bounds."

A paper on the study will be published in the Jan. 28 issue of Science. The study was supported by the German Research Foundation; the Academy of Sciences, Humanities and Literature in Mainz, Germany; and the Norwegian Research Council.

Other study co-authors included Kirstin Werner and Evguenia Kandiano of the Leibniz Institute of Marine Sciences, Steffen Sorensen, Katarzyna Zamelczyk, Katrine Husum and Morten Hald from the University of Tromso in Norway and Gereon Budeus of the Alfred Wegener Institute of Polar and Marine Research in Bremerhaven, Germany.

Since continuous meteorological and oceanographic data for the Fram Strait reach back only 150 years, the team drilled ocean sediment cores dating back 2,000 years to determine past water temperatures. The researchers used microscopic, shelled protozoan organisms called foraminifera -- which prefer specific water temperatures at depths of roughly 150 to 650 feet -- as tiny thermometers.

In addition, the team used a second, independent method that involved analyzing the chemical composition of the foraminifera shells to reconstruct past water temperatures in the Fram Strait, said Marchitto.

The Fram Strait branch of the North Atlantic Current is the major carrier of oceanic heat to the Arctic Ocean. In the eastern part of the strait, relatively warm and salty water enters the Arctic. Fed by the Gulf Stream Current, the North Atlantic Current provides ice-free conditions adjacent to Svalbard even in winter, said Marchitto.

"Cold seawater is critical for the formation of sea ice, which helps to cool the planet by reflecting sunlight back to space," said Marchitto. "Sea ice also allows Arctic air temperatures to be very cold by forming an insulating blanket over the ocean. Warmer waters could lead to major sea ice loss and drastic changes for the Arctic."

The rate of Arctic sea ice decline appears to be accelerating due to positive feedbacks between the ice, the Arctic Ocean and the atmosphere, Marchitto said. As Arctic temperatures rise, summer ice cover declines, more solar heat is absorbed by the ocean and additional ice melts. Warmer water may delay freezing in the fall, leading to thinner ice cover in winter and spring, making the sea ice more vulnerable to melting during the next summer.

Air temperatures in Greenland have risen roughly 7 degrees F in the past several decades, thought to be due primarily to an increase in Earth's greenhouse gases, according to CU-Boulder scientists.

"We must assume that the accelerated decrease of the Arctic sea ice cover and the warming of the ocean and atmosphere of the Arctic measured in recent decades are in part related to an increased heat transfer from the Atlantic," said Spielhagen.

Contact

Robert Spielhagen, 011-49-431-600-2855
rspielhagen@ifm-geomar.de
Thomas Marchitto, 303-492-7739
Thomas.Marchitto@colorado.edu

The NSF-funded Climate Literacy & Energy Awareness Network (CLEAN) assembles a new peer-reviewed digital collection as part of the National Science Digital Library (NSDL) featuring teaching materials centered on climate and energy science for grades 6-16 and for citizens.

The CLEAN Pathway project uses the Essential Principles of Climate Science (CCEP 2009) and newly-developed Energy Awareness Principles to steward a broad collection of teaching materials that facilitate students, teachers, and citizens becoming climate literate and informed about climate and energy science and solutions.

The first part of the collection was launched in the fall of 2010. Each featured teaching material has undergone a rigorous review process and provides teaching tips by experts on how to implement the materials in the classroom. All materials are aligned with Benchmarks for Science Literacy. The alignment with the National Science Education Standards and the Excellence in Environmental Education Guidelines for Learning through interactive strandmaps will be completed by the fall of 2011.

Efforts to build a community of practitioners in climate education have started and will continue in the following years. In the spring of 2011 the CLEAN team will offer professional development opportunities related to the collection.

December 15, 2008

Rocky Mountain ski areas face dramatic changes this century as the climate warms, including best-case scenarios of shortened ski seasons and higher snowlines and worst-case scenarios of bare base areas and winter rains, says a new Colorado study.

The study indicates snowlines -- elevations below which seasonal snowpack will not develop -- will continue to rise through this century, moving up more than 2,400 feet from the base areas of Colorado's Aspen Mountain and Utah's Park City Mountain by 2100, said University of Colorado at Boulder geography Professor Mark Williams. Williams and Brian Lazar of Stratus Consulting Inc. of Boulder combined temperature and precipitation data for Aspen Mountain and Park City Mountain with general climate circulation models for the study.

The pair came up with three scenarios for each of the two ski havens for the years 2030, 2075 and 2100. The low-emissions scenario is based on the presumption that the world begins reducing CO2 emissions, said Williams. The "business-as-usual" scenario assumes the future rate of CO2 increase will be similar to the current rate, while the high-emissions scenario assumes future CO2 emissions will increase over the present rate.

Their forecasts indicate the "business as usual" scenario will cause average temperatures to rise by nearly 4 degrees Fahrenheit at Aspen and Park City by 2030 and 8.6 degrees F in Aspen and 10.4 degrees F for Park City by 2100, said Williams. A paper by Williams and Lazar was presented at the Fall Meeting of the American Geophysical Union held Dec. 15-19 in San Francisco.

"Ski industry officials know that warming is real, and that small changes in climate have substantial effects on ski areas," said Williams, also a fellow at CU-Boulder's Institute of Arctic and Alpine research. "The bad news is that the past five years of global CO2 emissions have exceeded our high-emissions scenario."

Under each of the emissions scenarios, the length of the ski seasons in Aspen and Park City by 2030 "will be squeezed on each shoulder," with delayed snowpack and earlier melting seasons, he said. Under the high-emissions scenario, Park City will have no snowpack at its base by 2100 and winter precipitation will come in the form of rain.

While the modeling by Williams and Lazar targeted Aspen Mountain and Park City, other ski areas in the Rockies and beyond are likely to be similarly or more drastically affected, said Williams. Many ski areas in California's Sierra Nevada, the Cascade Mountains in Oregon and Washington, and smaller ski areas in the mid-eastern portion of America like Pennsylvania and West Virginia, for example, could be forced out of business in the coming decades as air temperatures continue to warm, he said.

The key to the survival of the larger ski areas in the Rockies is adaptation, said Williams. Ski resorts must expand operations to higher elevations and more northerly parcels of land. They also must beef up gondola transportation systems to shuttle large loads of skiers efficiently from base areas with scant or no snow to snow-packed facilities located at higher elevations, he said.

At most Rocky Mountain ski areas, snowmaking will have to be stepped up considerably in the coming decades, said Williams. Increases in man-made snow will require the diversion and storage of large amounts of water, a challenging and expensive proposition since water rights are already over-appropriated throughout much of the West, he said.

Aspen Mountain, for example, may have to triple its snowmaking efforts in the coming decades because of warming temperatures, meaning an additional 50 cubic feet per second of water must be obtained per month, said Williams. But since appropriating significant amounts of winter water from streams adjacent to most ski areas would leave insufficient flows to maintain healthy aquatic ecosystems, resort operators are looking further and further afield for available water, he said.

"The bottom line is that in order to survive, these ski areas will need to find the necessary water wherever they can and hold it in storage to satisfy future snowmaking needs," Williams said. "Ski resort operators are really scrambling."

The new study was sponsored by Aspen Mountain and the Park City Mountain Resort said Lazar, who noted that two nonprofits -- the Aspen Global Change Institute and the Park City Foundation -- are working with the ski areas to better understand environmental climate change. "The results from studies like ours allow ski areas to try and better plan for the future, including how to be proactive on climate change in the community and region," said Lazar.

Williams and Lazar said many U.S. ski areas will likely follow the lead of ski areas in the European Alps by moving water from basin to basin over long distances and storing it at high elevations to satisfy future snowmaking needs. Ski areas could

generate their own hydropower by pumping water into and out of narrow, deep artificial lakes and small dams lined with plastic to minimize evaporation in the summers.

"It would be a win-win situation," Williams said. "The ski areas could recover some of their costs incurred from purchasing expensive water rights, providing some of their own hydropower to help run the resorts."

Snowmaking has been on the increase in the Alps for decades, where air temperatures have increased nearly 4 degrees F in the past 30 years, said Williams. In the Italian Alps, 70 percent of the skiable terrain is covered by artificial snow, and ski areas in the French Alps now make about 30 percent of their snow, he said.

Studies have shown that private jets that fly celebrities and vacationers in and out of Aspen for winter ski jaunts and summer recreation trips are by far the biggest CO2 emitters in the Roaring Fork Valley.

View the video here.

Contact

Mark Williams, 303-492-8830
markw@culter.colorado.edu
Brian Lazar, 303-381-8000
BLazar@stratusconsulting.com

January 14, 2011

Joint news release from the American Geophysical Union, CU-Boulder Laboratory for Atmospheric and Space Physics and Naval Research Laboratory

WASHINGTON—Scientists have taken a major step toward accurately determining the amount of energy that the sun provides to Earth, and how variations in that energy may contribute to climate change.

In a new study of laboratory and satellite data, researchers report a lower value of that energy, known as total solar irradiance, than previously measured and demonstrate that the satellite instrument that made the measurement—which has a new optical design and was calibrated in a new way—has significantly improved the accuracy and consistency of such measurements.

The new findings give confidence, the researchers say, that other, newer satellites expected to launch starting early this year will measure total solar irradiance with adequate repeatability – and with little enough uncertainty – to help resolve the long-standing question of how significant a contributor solar fluctuations are to the rising average global temperature of the planet.

"Improved accuracies and stabilities in the long-term total solar irradiance record mean improved estimates of the sun's influence on Earth's climate," said Greg Kopp of the Laboratory for Atmospheric and Space Physics (LASP) of the University of Colorado Boulder.

Kopp, who led the study, and Judith Lean of the Naval Research Laboratory, in Washington, D.C., published their findings today in Geophysical Research Letters, a journal of the American Geophysical Union.

The new work will help advance scientists' ability to understand the contribution of natural versus anthropogenic causes of climate change, the scientists said. That's because the research improves the accuracy of the continuous, 32-year record of total solar irradiance, or TSI. Energy from the sun is the primary energy input driving Earth's climate, which scientific consensus indicates has been warming since the Industrial Revolution.

Lean specializes in the effects of the sun on climate and space weather. She said, "Scientists estimating Earth's climate sensitivities need accurate and stable solar irradiance records to know exactly how much warming to attribute to changes in the sun's output, versus anthropogenic or other natural forcings."

The new, lower TSI value was measured by the LASP-built Total Irradiance Monitor (TIM) instrument on the NASA Solar Radiation and Climate Experiment (SORCE) spacecraft. Tests at a new calibration facility at LASP verify the lower TSI value. The ground-based calibration facility enables scientists to validate their instruments under on-orbit conditions against a reference standard calibrated by the National Institute of Standards and Technology (NIST). Before the development of the calibration facility, solar irradiance instruments would frequently return different measurements from each other, depending on their calibration. To maintain a long-term record of the sun's output through time, scientists had to rely on overlapping measurements that allowed them to intercalibrate among instruments.

Kopp said, "The calibration facility indicates that the TIM is producing the most accurate total solar irradiance results to date, providing a baseline value that allows us to make the entire 32-year record more accurate. This baseline value will also help ensure that we can maintain this important climate data record for years into the future, reducing the risks from a potential gap in spacecraft measurements."

Lean said, "We are eager to see how this lower irradiance value affects global climate models, which use various parameters to reproduce current climate: incoming solar radiation is a decisive factor. An improved and extended solar data record will make it easier for us to understand how fluctuations in the sun's energy output over time affect temperatures, and how Earth's climate responds to radiative forcing."

Lean's model, which is now adjusted to the new lower absolute TSI values, reproduces with high fidelity the TSI variations that TIM observes and indicates that solar irradiance levels during the recent prolonged solar minimum period were likely comparable to levels in past solar minima. Using this model, Lean estimates that solar variability produces about 0.1o Celsius (0.18o Fahrenheit) global warming during the 11-year solar cycle, but is likely not the main cause of global warming in the past three decades.

Greg Kopp
(303) 735-0934
Greg.Kopp@lasp.colorado.edu

Judith Lean
(202) 767 5116
jlean@ssd5.nrl.navy.mil

AGU Contact:
Peter Weiss
pweiss@agu.org

CU-Boulder LASP Contact:
Stephanie Renfrow
Stephanie.renfrow@lasp.colorado.edu

CU-Boulder Contact:
Jim Scott
Jim.Scott@Colorado.edu

NRL Contact:
Donna McKinney
donna.mckinney@nrl.navy.mil

December 16, 2010

Wind turbines in Midwestern farm fields may be doing more than churning out electricity. The giant turbine blades that generate renewable energy might also help corn and soybean crops stay cooler and drier, help them fend off fungal infestations and improve their ability to extract growth-enhancing carbon dioxide from the air and soil.

The preliminary findings of a months-long study that examines how wind turbines on farmlands interact with surrounding crops were presented today at the annual fall meeting of the American Geophysical Union in San Francisco. The presentation was made by researcher Gene Takle of the U.S. Department of Energy's Ames Laboratory and Julie Lundquist, assistant professor in the University of Colorado at Boulder's atmospheric and oceanic studies department.

"We've finished the first phase of our research, and we're confident that wind turbines do produce measureable effects on the microclimate near crops," said agricultural meteorology expert Takle, who also is the director of the Climate Science Program at Iowa State University.

According to Takle, turbine blades channel air downward, in effect bathing the crops below with the increased airflow they create.

"Our laser instrument could detect a beautiful plume of increased turbulence that persisted even a quarter-mile downwind of a turbine," said Lundquist, who also is a joint appointee at the U.S. Department of Energy's National Renewable Energy Laboratory, and a fellow of the Renewable and Sustainable Energy Institute, a joint institute of CU-Boulder and NREL.

Lundquist's team uses a specialized laser known as lidar to measure winds and turbulence from near the Earth's surface to well above the uppermost tip of a turbine blade.

Both Lundquist and Takle stressed their early findings have yet to definitively establish whether or not wind turbines are beneficial to the health and yield potential of soybeans and corn planted nearby. However, their finding that the turbines increase airflow over surrounding crops suggests this is a realistic possibility.

"Because wind turbines generate turbulence and the mixing of air downwind, they may accelerate the natural exchange processes between crops and the lower part of the atmosphere," said Lundquist.

For example, the sun warms crops and some of that heat is given off to the atmosphere. Extra air turbulence likely speeds up this heat exchange, so crops may stay slightly cooler on hot days, Lundquist said. On cold nights, the turbulence created by the wind turbines stirs the lower atmosphere and keeps nighttime temperatures around the crops warmer.

"In both the spring and in the fall, we suspect that turbines' effects are beneficial by warming and perhaps preventing a frost, thus extending the growing season," said Lundquist.

Wind turbines also may have positive effects on crop moisture levels. Extra turbulence may help dry the dew that settles on plants, minimizing the amount of time fungi and toxins can grow on plant leaves. Additionally, drier crops at harvest help farmers reduce the cost of artificially drying corn or soybeans.

Another potential benefit to crops is that increased airflows could enable corn and soybean plants to more readily extract CO2, a needed fuel for crops, from the atmosphere and the soil, thus helping the crops' ability to perform photosynthesis.

Takle's wind turbine predictions are based on years of research on so-called agricultural shelter belts, which are rows of trees in a field designed to slow high-speed natural winds.

"In a simplistic sense, a wind turbine is nothing more than a tall tree with a well-pruned stem," said Takle. "For a starting point for this research, we adapted a computational fluid model that we use to understand trees, but we plan to develop a new model specific to wind turbines as we gather more data."

The team's initial measurements consisted of visual observations of wind turbulence upwind and downwind of the turbines. The team also used wind-measuring instruments called anemometers to determine the intensity of the turbulence. The bulk of the wind-turbulence measurements and the crop-moisture, temperature and CO2 measurements took place in the spring and summer of this year.

"We anticipate the impact of wind turbines to be subtle, but in certain years and under certain circumstances the effects could be significant," said Takle. "When you think about a summer with a string of 105-degree days, extra wind turbulence from wind turbines might be helpful. If turbines can bring the temperature down below 100 degrees that could be a big help for crops."

The CU-Boulder and ISU teams hope to continue their measurements throughout the next growing season.

"These data are quite encouraging, and we look forward to collecting more data to ensure the certainty of these results," said Lundquist. "As wind energy expands in future years to provide a domestic source of energy, we'll need robust measurements to understand and predict the impacts of that expansion."

The research was funded or supported by Ames Laboratory, the Department of Energy's Office of Energy Efficiency and Renewable Energy, the U.S. National Laboratory for Agriculture and the Environment, CU-Boulder and NREL.

To view a video of Takle discussing the study of wind turbines on farmland visit www.youtube.com/watch?v=r7qNNvYVKI4&feature=player_embedded

Contact
Julie Lundquist, 303-492-8932
julie.lundquist@colorado.edu

Elizabeth Lock, 303-492-3117
elizabeth.lock@colorado.edu