Cooperative Institute for Research in Environmental Sciences

A new study shows that water vapor high in the sky and the temperature at the Earth‘s surface are linked in a “feedback loop” that further warms our climate. Published today, this study gives the first estimate of the size of the feedback‘s effect, which may help researchers improve modeling to better understand climate change.

“Water vapor in the stratosphere increases in tandem with increases in the Earth‘s surface temperature,” said coauthor Sean Davis, a scientist with the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder, who works at the NOAA Earth System Research Laboratory. “Because water vapor is a greenhouse gas, this generates additional warming. We show that this feedback loop could be about 10% of the climate warming from all greenhouse gases.”

The new study, published online on September 30 in the prestigious journal Proceedings of the National Academy of Sciences, quantifies the magnitude of the stratospheric water vapor feedback for the first time, making use of satellite observations and a climate model.

“While it‘s not really surprising that this process is going on, we were surprised at how important the process is for our climate system,” said Andrew Dessler, an atmospheric sciences professor at Texas A&M University who was lead author of the paper. Dessler was a CIRES Visiting Fellow this year, working with Davis and other colleagues on this paper.

For well over 100 years it has been known that increased emissions of greenhouse gases such as carbon dioxide will warm the planet. As the lowest layer of the atmosphere, called the troposphere (surface to ~7 miles), is warmed, the air becomes more humid because warmer air holds more water vapor. This “tropospheric water vapor feedback” approximately doubles the initial warming caused by carbon dioxide.

The new study shows that in addition to the well-understood tropospheric water vapor feedback on climate change, there is also a significant amplifying feedback associated with water vapor in the stratosphere, the layer of the atmosphere above the troposphere that extends to ~30 miles above Earth‘s surface. This “stratospheric water vapor feedback,” although hypothesized by previous studies, has remained elusive to quantification.

The new results suggest that the stratospheric water vapor feedback may be an important component of our climate system. The researchers estimated that at a minimum this feedback adds another ~5-10% to the climate warming from the addition of greenhouse gases, and is possibly substantially more than this amount.

Most climate models contain a representation of stratospheric water vapor, so this feedback is already operating in the models to some extent. Thus, this new finding does not necessarily mean that models have underestimated future global warming. However, since the importance of this feedback has not been previously recognized, it is possible that the stratospheric water vapor feedback may help to explain some of the spread among future projections of climate change from different models. Indeed, of the ~20 models participating in the 5th Assessment report of the Intergovernmental Panel on Climate Change (IPCC), the authors found substantial differences among the models‘ future simulation of stratospheric water vapor.

Though the study has moved understanding an important step forward, many questions remain about the role of stratospheric water vapor in climate.

“The stratospheric water vapor feedback effect could be even larger than the 5-10% we found in our study,” said Davis. “Our analysis suggests that the pathways for water vapor to reach the stratosphere are not completely understood, so we view our numbers as a minimum estimate of the effect of this feedback.”

The authors of the study are Andrew Dessler (lead author) and Tao Wang (Texas A&M University); Mark Schoeberl (Science and Technology Corporation); Sean Davis (CIRES and NOAA-ESRL); and Karen Rosenlof (NOAA-ESRL).

CIRES is a joint institute of the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado Boulder.

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NOAA, CIRES, international scientists expect improvement in upcoming years

For nearly 50 years, scientists with NOAA have launched high-altitude balloons from the South Pole, to understand why a hole was forming in the protective ozone layer high in the atmosphere. Now, organizations around the world track the infamous ozone hole through these ballon-sondes, satellite measurements and ground instruments.

This year, the ozone hole was a little smaller than in years past, those measurements showed, and ozone levels in a critical region of the atmosphere did not drop as low.

“We cannot say that this represents recovery, but it is certainly good news to see this year on the higher side of the average ozone range,” said NOAA’s Bryan Johnson, with the Earth System Research Laboratory (ESRL) in Boulder, Colo.

Johnson works with colleagues at NOAA and the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder to track and understand trends in seasonal ozone from measurements made by a two-person NOAA crew at South Pole Station. Earth’s ozone layer shields life on the planet’s surface from ultraviolet radiation that can cause skin cancer and damage plants.

The Antarctic ozone hole began making a yearly appearance in the early 1980s, caused by chlorine released from man-made chemicals called chlorofluorocarbons, or CFCs. Under the the Montreal Protocol of 1987 and its later amendments, countries agreed to phase out most ozone-depleting substances, which were used in fire extinguishers and as other foams, sprays, as solvents, refrigerants and in other industries. According to NOAA global observations, chlorine levels at the poles reached a maximum at the beginning of this century and are now on the decline.

“It takes the atmosphere a while to break down these long-lived chemicals, and some can remain in the atmosphere for about 100 years,” said NOAA ESRL atmospheric scientist Steve Montzka, who is also a CIRES Fellow.

When conditions are right—as they are in the Antarctic spring—chlorine from ozone-depleting gases can rapidly break apart ozone molecules, reducing ozone over Antarctica by one half in just a couple of weeks. The World Meteorological Organization reports that this year’s ozone hole stretched about 8 million square miles (21 million square kilometers) in late September, about the size of the United States, Canada and Mexico combined. For comparison, the Antarctic ozone hole stretched to more than 10 million square miles in the record year of 2006.

Of particular interest is the region between 7 and 12 miles altitude (12-20 kilometers). There, ozone levels are more strongly influenced by man-made ozone-depleting chemicals than by natural variations in meteorology. This year, ozone levels in this region of the atmosphere only dropped to about 25 Dobson Units (DUs) in late September; in previous years, they plummeted to less than 10 DUs.

In a sign of the effectiveness of the Montreal Protocol, the ozone hole over Antarctica is likely to show signs of recovery within the next decade. NOAA and CIRES scientists will continue their long-term atmospheric measurements of ozone and ozone-depleting gases not only to capture evidence of recovery, though. Some chemicals used as substitutes for ozone-depleting gases are potent greenhouse gases, too, and pose a potentially significant climate threat.

“The need for observations will remain paramount,” said Jim Butler, director of the Global Monitoring Division of NOAA’s ESRL.  

CIRES is a joint institute of the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado Boulder.

Science teams from NASA and the National Oceanic and Atmospheric Administration (NOAA) have been monitoring the ozone layer from the ground and with a variety of instruments on satellites and balloons since the 1970s. These ozone instruments capture different aspects of ozone depletion. The independent analyses ensure that the international community understands the trends in this critical part of Earth's atmosphere. The resulting views of the ozone hole have differences in the computation of the size of the ozone hole, its depth, and record dates. More from NOAA here; and from NASA here.

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America’s once-abundant tallgrass prairies—which have all but disappeared—were home to dozens of species of grasses that could grow to the height of a man, hundreds of species of flowers, and herds of roaming bison.

For the first time, a research team led by the University of Colorado Boulder has gotten a peek at another vitally important but rarely considered community that also once called the tallgrass prairie home: the diverse assortment of microbes that thrived in the dark, rich soils beneath the grass.

“These soils played a huge role in American history because they were so fertile and so incredibly productive,” said Noah Fierer, a fellow at the Cooperative Institute for Research in Environmental Sciences (CIRES) and lead author of the study published today in the journal Science“They don’t exist anymore except in really small parcels. This is our first glimpse into what might have existed across the whole range.”

CIRES is a joint institute of CU Boulder and NOAA.

The remarkable fertility of soils beneath the tallgrass prairie—which once covered more than 150 million U.S. acres, from Minnesota south to Texas and from Illinois west to Nebraska—were also the prairie’s undoing. Attracted by the richness of the dirt, settlers began to plow up the prairie more than a century and a half ago, replacing the native plants with corn, wheat, soybeans and other crops. Today, only remnants of the tallgrass prairie remain, covering just a few percent of the ecosystem’s original range.

For the study, Fierer, an associate professor of microbial ecology, and his colleagues used samples of soil collected from 31 different sites spread out across the prairie’s historical range. The samples—which were collected by study co-author Rebecca McCulley, a grassland ecologist at the University of Kentucky—came largely from nature preserves and old cemeteries.

“It was very hard to find sites that we knew had never been tilled,” Fierer said. “As soon as you till a soil, it’s totally different. Most gardeners are familiar with that.”

The researchers used DNA sequencing to characterize the microbial community living in each soil sample. The results showed that a poorly understood phylum of bacteria, Verrucomicrobia, dominated the microbial communities in the soil.

“We have these soils that are dominated by this one group that we really don’t know anything about,” Fierer said. “Why is it so abundant in these soils? We don’t know.”

While Verrucomicrobia were dominant across the soil samples, the microbial makeup of each particular soil sample was unique. To get an idea of how soil microbial diversity might have varied across the tallgrass prairie when it was still an intact ecosystem, the researchers built a model based on climate information and the data from the samples.

“I am thrilled that we were able to accurately reconstruct the microbial component of prairie soils using statistical modeling and data from the few remaining snippets of this vanishing ecosystem,” said Katherine Pollard, an investigator at the Gladstone Institutes in San Francisco and a co-author of the paper.

Fierer and his colleagues are already hard at work trying to grow Verrucomicrobia in the lab to better understand what it does and the conditions it favors. But even without a full understanding of the microbes, the research could bolster tallgrass prairie restoration efforts in the future.

“Here’s a group that’s really critical in the functioning of these soils. So if you’re trying to have effective prairie restoration, it may be useful to try and restore the below-ground diversity as well,” Fierer said.

CU Boulder co-authors on the paper include Jonathan Leff, also of CIRES and the Department of Ecology and Evolutionary Biology; and Rob Knight, a Howard Hughes Medical Institute Early Career Scientist in the Department of Chemistry and Biochemistry.

Other co-authors are Joshua Ladau of the Gladstone Institutes; Jose Clemente, of the Mount Sinai School of Medicine in New York; and Sarah Owens and Jack Gilbert, both of Argonne National Laboratory in Illinois.

The research was funded by the National Science Foundation, the Howard Hughes Medical Institute, the Gordon & Betty Moore Foundation, the U.S. Department of Energy and the USDA National Research Initiative.

IRES is a joint institute of the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado Boulder.



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In an example of the challenges water-strapped Western cities will face in a warming world, new research shows that every degree Fahrenheit of warming in the Salt Lake City region could mean a 1.8 to 6.5 percent drop in the annual flow of streams that provide water to the city.

By midcentury, warming Western temperatures may mean that some of the creeks and streams that help slake Salt Lake City’s thirst will dry up several weeks earlier in the summer and fall, according to the new paper, published today in the journal Earth Interactions. The findings may help regional planners make choices about long-term investments, including water storage and even land-protection policies.

“Many Western water suppliers are aware that climate change will have impacts, but they don’t have detailed information that can help them plan for the future,” said lead author Tim Bardsley, with NOAA’s Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder. “Because our research team included hydrologists, climate scientists and water utility experts, we could dig into the issues that mattered most to the operators responsible for making sure clean water flows through taps and sprinklers without interruption.”

Bardsley works for the CIRES Western Water Assessment, from the NOAA Colorado Basin River Forecast Center in Salt Lake City. For the new paper, he worked closely with colleagues from the city’s water utility, the National Center for Atmospheric Research (NCAR), NOAA’s Earth System Research Laboratory and the University of Utah.

The team relied on climate model projections of temperature and precipitation in the area, historical data analysis, and a detailed understanding of the region from which the city utility obtains water. The study also used NOAA streamflow forecasting models that provide information for Salt Lake City’s current water operations and management.

The picture that emerged was similar, in some ways, to previous research on the water in the Interior West: Warmer temperatures alone will cause more of the region’s precipitation to fall as rain than snow, leading to earlier runoff and less water in creeks and streams in the late summer and fall. 

“Many snow-dependent regions follow a consistent pattern in responding to warming, but it’s important to drill down further to understand the sensitivity of watersheds that matter for individual water supply systems,” said NCAR’s Andy Wood, a co-author.

The specifics in the new analysis—which creeks are likely to be impacted most and soonest, how water sources on the nearby western flank of the Wasatch Mountains and the more distant eastern flank will fare—are critical to water managers with Salt Lake City.

“We are using the findings of this sensitivity analysis to better understand the range of impacts we might experience under climate change scenarios,” said co-author Laura Briefer, water resources manager at the Salt Lake City Department of Public Utilities. “This is the kind of tool we need to help us adapt to a changing climate, anticipate future changes and make sound water-resource decisions.”

"Water emanating from our local Wasatch Mountains is the lifeblood of the Salt Lake Valley, and is vulnerable to the projected changes in climate," said Salt Lake City mayor Ralph Becker. "This study, along with other climate adaptation work Salt Lake City is doing, helps us plan to be a more resilient community in a time of climate change."

Authors of the new paper, “Planning for an Uncertain Future: Climate Change Sensitivity
Assessment toward Adaptation Planning for Public Water Supply,” are Tim Bardsley, CIRES Western Water Assessment; Andrew Wood, National Center for Atmospheric Research and formerly of NOAA’s Colorado Basin River Forecast Center; Mike Hobbins, NOAA’s Earth System Research Laboratory, and formerly NOAA’s Colorado Basin River Forecast Center; Tracie Kirkham, Laura Briefer, and Jeff Niermeyer, Salt Lake City Department of Public Utilities, Salt Lake City, Utah; and Steven Burian, University of Utah, Salt Lake City.

Earth Interactions is jointly published by the American Geophysical Union, the American Meteorological Society, and the Association of American Geographers.

CIRES is a joint institute of NOAA and CU Boulder.


  1. Tim Bardsley, lead author, CIRES WWA researcher,, 801-557-3783 (mobile)
  2. Laura Briefer, co-author, Salt Lake City Department of Public Utilities,, 801-483-6741
  3. Katy Human, CIRES communications director,, 303-735-0196
  4. David Hosansky, NCAR media relations manager,, 303-497-8611
  5. Karen Hale, Office of the Mayor, Salt Lake City, communications director,, 801-535-7739

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CIRES is a partnership of NOAA and CU Boulder.

Reducing the amount of desert dust swept onto snowy Rocky Mountain peaks could help Western water managers deal with the challenges of a warmer future, according to a new study led by researchers at NOAA’s Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder.

With support from the CIRES Western Water Assessment (WWA) and NASA’s Interdisciplinary Science program, CIRES’ Jeffrey Deems and his colleagues examined the combined effects of regional warming and dust on the Colorado River, which is fed primarily by snowmelt.

During recent years, desert dust has been settling thick and dark on the snowpack in the northern Rocky Mountain headwaters of the Colorado River, and snowpack is melting out as many as six weeks earlier than it did in the 1800s, according to the new assessment, published last week in Hydrology and Earth System Sciences. Snow dusted with dark particles absorbs more of the Sun’s rays and melts faster than clean snow.

Add the regional warming expected in the future, and the situation seems likely to grow more dire for the 40 million people who depend on the Colorado River for water. The river’s flow falls by more than 20 percent by 2100 in some of the future climate scenarios Deems and his colleagues investigated. Moreover, warming could make dust problems worse, by increasing the risk of drought.

“But we may be able to do something about dust,” said Deems, who works with WWA and CIRES’ National Snow and Ice Data Center. “If the future normal is this extreme dust scenario and we can push that scenario back to lower dust levels with land restoration or management, we could keep the snow in the mountains longer, and maybe even get some of that water back.”

Since the mid-1800s, human land use activities have disturbed Southwestern desert soils and broken up the soil crust that curbs wind erosion, leading to increased dust. In previous research, Deems and his colleagues showed that increasing dustiness leads to accelerated snowpack melt.

That earlier work was based on the moderately dusty years of 2005–2008, with about five times as much dust than in the 1800s. But during 2009, 2010 and 2013, unprecedented amounts of desert dust fell on Colorado snowpacks, about five times more than observed from 2005–2008. Moreover, other researchers have reported that climate change is likely to increase the frequency and intensity of drought in the Southwest, which could increase dust problems further by harming the grasses and shrubs that reduce surface wind speeds.

For the new work, the researchers used climate and hydrology models to investigate the effect of that “extreme dust” on the Colorado River’s flow now and in the future, as the Southwest continues to warm. Snowmelt in the extreme dust scenario shifted even earlier in the season, by another three weeks, pulling peak water levels in the Colorado River to earlier in the spring and leaving less water for later in the year.

“In the Upper Colorado River Basin, the snowpack is our most important reservoir,” said co-author Thomas Painter of NASA’s Jet Propulsion Laboratory. “With continued dusty years and greater warming, water managers will have to make their decisions very early in the season. No longer will they have the nice long snowmelt season, shortened as it already has been, to see how snowmelt runoff is going.”

The research team also found a subtle shift on the total water loss in the Colorado River, from a loss of 5 percent estimated during the moderate dust years of 2005–2008, to a total loss of about 6 percent lost during extremely dusty years. This relatively small change is due primarily to the fact that as snowmelt creeps earlier and earlier in the year, the Sun’s angle in the sky is shallower and provides less energy for evaporation than it does later in the spring.

“Our results suggest that if we can adopt dust-reducing land management strategies and rehabilitate major dust sources, we can keep our snow on the mountains longer, and perhaps offset some of the emerging climate impacts,” said co-author Brad Udall, director of the Getches-Wilkinson Center for Natural Resources, Energy and the Environment at CU Boulder. “Dust reduction could be a very powerful strategy to help us adapt to the growing impacts of climate change on our precious water supplies in the American Southwest.”

CIRES is a partnership of NOAA and CU Boulder.

CIRES, NOAA scientists find switch to natural gas power plants means fewer air pollutants

Power plants that use natural gas and a new technology to squeeze more energy from the fuel release far less of the greenhouse gas carbon dioxide than coal-fired power plants do, according to a new analysis accepted for publication Jan. 8 in the journal Earth’s Future, a journal of the American Geophysical Union. The so-called “combined cycle” natural gas power plants also release significantly less nitrogen oxides and sulfur dioxide, which can worsen air quality.

“Since more and more of our electricity is coming from these cleaner power plants, emissions from the power sector are lower by 20, 30, even 40 percent for some gases, since 1997,” said lead author Joost de Gouw, an atmospheric scientist with NOAA’s Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder.

De Gouw, who works at NOAA’s Earth System Research Laboratory (ESRL), and his NOAA and CIRES colleagues analyzed data from systems that continuously monitor emissions at power plant stacks around the country. Previous aircraft-based studies have shown these stack measurements are accurate for carbon dioxide CO2 and for nitrogen oxides and sulfur dioxide. Nitrogen oxides and sulfur dioxide can react in the atmosphere to form tiny particles and ozone, which can cause respiratory disease.

To compare pollutant emissions from different types of power plants, the scientists calculated emissions per unit of energy produced, for all data available between 1997 and 2012. During that period of time, on average:

Coal-based power plants emitted 915 grams (32 ounces) of CO2 per kilowatt hour of energy produced; Natural gas power plants emitted 549 grams (19 ounces) CO2 per kilowatt hour; and Combined cycle natural gas plants emitted 436 grams (15 ounces) CO2 per kilowatt hour.

In combined cycle natural gas plants, operators use two heat engines in tandem to convert a higher fraction of heat into electrical energy. For context, U.S. households consumed 11,280 kilowatt hours of energy, on average, in 2011, according to the U.S. Energy Information Agency. This amounts to 11.4 metric tons per year of CO2 per household, if all of that electricity were generated by a coal power plant, or 5.4 metric tons if it all came from a natural gas power plant with combined cycle technology.

The researchers reported that between 1997 and 2012, the fraction of electric energy in the United States produced from coal gradually decreased from 83 percent to 59, and the fraction of energy from combined cycle natural gas plants rose from none to 34 percent.

That shift in the energy industry meant that power plants, overall, sent 23 percent less CO2 into the atmosphere last year than they would have, had coal been providing about the same fraction of electric power as in 1997, de Gouw said. The switch led to even greater reductions in the power sector’s emissions of nitrogen oxides and sulfur dioxide, which dropped by 40 percent and 44 percent, respectively.

The new findings are consistent with recent reports from the Energy Information Agency that substituting natural gas for coal in power generation helped lower power-related carbon dioxide emissions in 2012.

The authors noted that the new analysis is limited to pollutants emitted during energy production and measured at stacks. The paper did not address levels of greenhouse gases and other pollutants that leak into the atmosphere during fuel extraction, for example. To investigate the total atmospheric consequences of shifting energy use, scientists need to continue collecting data from all aspects of energy exploration, production and use, the authors concluded.

Authors of the new paper, “Reduced Emissions of CO2, NOx and SOfrom U.S. Power Plants Due to the Switch from Coal to Natural Gas with Combined Cycle Technology,” are Joost de Gouw (CIRES), David Parrish (NOAA ESRL), Greg Frost (CIRES) and Michael Trainer (NOAA).

CIRES is a joint institute of the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado Boulder.


To many who live along the road, the roar of traffic on the Diagonal Highway between Boulder and Longmont, Colo. is nothing but a nuisance. But to a small team of physicists in Boulder, the noise proved inspirational. The group, led by Oleg Godin of CIRES, used the traffic noise on “The Diagonal” to accurately measure wind speed. The scientists reported the proof-of-concept study this month in the Journal of the Acoustic Society of America Express Letters.  

“We have demonstrated for the first time that we can use ambient noise to measure wind speeds,” said Godin, lead author of the new study and a senior research scientist with NOAA’s Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder. Godin works in NOAA’s Earth System Research Laboratory (ESRL). Eventually, the method could be used to cheaply measure wind speed and direction in the atmosphere, critical information for weather forecasts, he said, or even to study the rotation of Earth’s core.

The technique he and his colleagues use is called acoustic tomography, and it is similar to the use of sonar (sound navigation and ranging) to map underwater objects and measure temperatures below the ocean surface.

Traditional sonar techniques require beaming loud signals through water bodies and recording their arrival at underwater microphones. Sound travels faster or slower, depending on water temperature. A few years ago, Godin and his colleagues figured out how to use ocean noises such as breaking waves, singing whales and passing ships to measure underwater temperatures without relying on loud and potentially disruptive sounds.

Now, they’ve applied that research to the atmosphere. In the air, wind speed and direction affect the propagation of sound waves.

During a series of experiments in 2012, the team set up four to five microphones, about 50-150 feet away from one another, in the median of Diagonal Highway close to Boulder. They also set up a conventional weather station, to provide “ground truth” information on wind speed and air temperatures between the microphones.

As cars rushed by, all microphones recorded the sounds, and Godin and his colleagues captured the tiny differences in when sounds arrived at each microphone. Using sophisticated mathematical techniques, they matched up the signals and arrival times to calculate the speed of wind between the microphones. Their measurements were extremely close to those recorded by the conventional weather station, within 1-3 miles per hour.

In concept, the same kind of “noise interferometry” method could be used to better measure the mass and heat carried by the Gulf Stream and even to understand the rotation of Earth’s core, Godin said. By comparing noise recorded simultaneously by two microphones, he and his colleagues can measure tiny differences between the time it took sound to travel in opposite directions between the microphones. This travel time difference, which scientists call “acoustic non-reciprocity,” is a very sensitive and robust measure of ocean current velocity or Earth’s core rotation.

Authors of the new paper, “Passive acoustic measurements of wind velocity and sound speed in air,” are Oleg Godin (CIRES scientist working in NOAA's ESRL) and Vladimir Irisov and Mikhail Charnotskii (Zel Technologies, LLC scientists working in NOAA's ESRL).

CIRES is a joint institute of the National Oceanic and Atmospheric Administration (NOAA) and the University of Colorado Boulder.



CIRES is a partnership of NOAA and CU Boulder.

NOAA and CIRES scientists, collaborators improve climate data access

When a city’s transportation infrastructure needs work, city planners can’t just look at yesterday’s traffic figures—they need to take into account long-term trends: How are driving patterns changing? Roads and mass transit projects last for decades, after all.

Likewise, planners are increasingly trying to take future weather patterns into account. “They’re often planning expenditures for things that will last 50 to100 years, and we know the climate will be changing in that 50 to 100 years,” said University of Michigan professor Richard Rood. “We’re trying to include that element of climate change in planning.”

With NOAA funding, Rood and colleagues, including lead developer Ben Koziol, a CIRES researcher in NOAA’s Earth System Research Laboratory, have built an open-source Python package, OpenClimateGIS, that aids users in the interpretation of climate data. OpenClimateGIS serves users already familiar with GIS systems, letting them work with data subsets for specific regions. A transportation expert, for example, can explore changes in freeze-thaw cycles, which might affect construction methods within her area.

Today, Rood and Koziol will attend the launch of the White House’s Climate Data Initiative. Their new software, still in development, is showing promise for serving many sectors, including stormwater planning (sewers get overwhelmed by intense rainfalls, which are on the rise in some areas) and emergency planning around dangerous heat waves (also on the rise in some areas).

“There are all these people working in forestry departments, ecologists, transportation people, water managers. They want to understand the impacts of climate on their work,” Rood said.

Rood said he was motivated to develop the GIS-based application because he found that students in a professional master’s-level course he taught couldn’t import climate data into the analysis systems that they relied on daily.

“They’d go to data archives climate scientists built, and either they couldn’t use the data or there was a high barrier to using it,” Rood said. “So they’d use old, outdated data.” His and Koziol’s work now allows GIS-based exploration of the latest climate data, such as outputs from the climate models used in the Climate Model Intercomparison Project (CMIP).

The package is customized to let planners explore data on the scales that matter to them—such as county-level, or municipality—and users can create “thresholds” that are important to them, not guessed at by scientists. In some parts of North Carolina, for example, planners worry about increasing frequency of heat waves. One of Rood and Koziol’s colleagues is using OpenClimateGIS to explore how two “downscaled” climate models project changing intensity and frequency of heat waves in two NC counties.

The software package is only one “product” of a suite of climate analysis tools planned by the broad community of climate scientists and developers that comprises the National Climate Predictions and Projections Platform. Another product in the works, ClimateTranslator, will let users explore climate data, using a graphical mapping interface, to better understand the impacts of climate on their systems and make more informed choices.

CIRES, the Cooperative Institute for Research in Environmental Sciences, is a partnership of NOAA and the University of Colorado Boulder. OpenClimateGIS development is funded by the NOAA Climate Program Office, and collaborators include the National Center for Atmospheric Research, the University of Michigan and the U.S. Geological Survey.

CIRES is a partnership of NOAA and CU Boulder.

New report summarizes changes on Navajo Nation lands, offers hope for resilience

In the U.S. Southwest, 2001-2010 was warmer than any decade in the 20th century. Heat waves are happening more often, cold waves less. On the Navajo Nation, drought conditions have dominated since 1994, punctuated by brief episodes of wetness, yet there have been even worse droughts in the Southwest in the last 2,000 years.

In the middle of this region are the Navajo Nation reservations lands, 27,000 square miles (the size of West Virginia) of arid to semi-arid land that’s home to more than 170,000 people.

A new report led by the University of Colorado Boulder, Considerations for Climate Change and Variability Adaptation on the Navajo Nation, synthesizes state-of-the-science information on the region’s climate, water cycle and ecology. And it goes much further, discussing social, legal, economic, infrastructural and other factors that affect people’s vulnerabilities to climate impacts as well as their adaptive capacity, and outlining one approach for how the region’s residents might plan for ongoing environmental change.

“It’s not only that the Navajo Nation is facing serious climate challenges,” said report lead author Julie Nania, Esq., with the Getches-Wilkinson Center for Natural Resources, Energy and the Environment at CU Boulder. “It’s also that in some cases, they may be vulnerable to climate-related impacts, for example, because many people run livestock,” she said.

“On the other hand, they may be particularly well-poised to take leadership on adaptation planning, because they have the sovereign authority to address some of these issues very effectively.”

During the past decade, intertribal organizations around the United States have started to recognize climate change and variability as significant factors that can affect tribal resources, livelihoods and cultures. The National Tribal Air Association calls climate change “perhaps the most pressing environmental issue of our time.”

The new report—more than 200 pages long—highlights potential and actual environmental changes occurring in the Southwest and Four Corners region. Among them:

  • Average annual temperatures in the U.S. Southwest increased by about 1.6 degrees Fahrenheit between 1901 and 2010.
  • There were more heat waves in the 2001-2010 decade than there were in 20th Century decades, on average.
  • Snowmelt and snowmelt-fed streamflow peaks occurred earlier in many areas.
  • On the Navajo Reservation, many streams that once flowed yearlong flow only intermittently now; and others once intermittent have dried entirely.
  • The growing season is longer by 17 days, compared with the 20th century.
  • Climate projections suggest that annual average temperatures in the Southwest will increase by between 2 and 9 degrees Fahrenheit by the end of the 21st century.
  • Moving sand dunes on the Navajo Reservation, which have buried homes, cropland and ranchlands since the 1950s, may become more widespread in the future.

The new report also presents an example of an adaptation planning and implementation process, applicable to any group facing disruption. It outlines many of the challenges that Navajo communities may face, considers the strengths and capacities that the Nation may already have in place to institute adaptation efforts and suggests potential adaptation strategies.

Nania said she and her co-authors hope Navajo Nation natural resource planners—some of whom worked closely with the authors of the new report—will find the information in it a helpful tool for the adaptive planning process. One example used in the report features the golden eagle, which is protected on Navajo Reservation lands. The bird’s numbers are declining on the Colorado Plateau, likely due in part to climate shifts and non-climatic factors. The report outlines a process that resource managers and the broader community could use to come up with effective ways to address the eagle's decline.

“We hope resource managers and communities will take this report and adapt it to suit their own needs,” said Dr. Karen Cozzetto, co-lead author on the report and a researcher with NOAA’s Cooperative Institute for Research in Environmental Sciences (CIRES) at CU Boulder. “They have the expertise and the knowledge to carry forward this kind of adaptation planning.”

“Climate adaptation planning is an opportunity not only to prepare for climate change," Cozzetto said, “but also to think bigger about what kind of communities we want to live in, and what kind of world we want to leave for our children.”

The report is available online. Lead authors are CU Boulder’s Julie Nania, Getches-Wilkinson Center for Natural Resources, Energy and the Environment, and Karen Cozzetto, CIRES Western Water Assessment. Contributing authors include Nicole Gillette, Ann Mariah Tapp, Sabre Duren, Michael Eitner and Beth Baldwin. Although this report is not a product of the Navajo Nation, the knowledge shared by tribal resource managers and other professionals across the Southwest has been incorporated throughout this report.

Support for this project was provided by the National Integrated Drought Information System (NIDIS), CIRES’ Western Water Assessment, the Getches-Wilkinson Center for Natural Resources, Energy and the Environment at the CU Boulder Law School and the CU Boulder Renewable and Sustainable Energy Institute.

CIRES is a partnership of NOAA and CU Boulder.



  • A high-resolution image is available for download through our Flickr account, News Releases photoset

CIRES is a partnership of NOAA and CU Boulder.

This news release is jointly issued by CIRES and the University of Colorado Boulder.

Teachers: Learn more about Navajo elders' observations of climate change, and the same from North Dakota tribal members. The CIRES Education and Outreach program helps maintain and review a collection of peer-reviewed educational resources called CLEAN (the Climate Literacy and Energy Awareness Network). Educators and others can find many other resources here.


Recent Stories

Findings may help researchers understand future of Greenland’s ice and snow

In 2012, temperatures at the summit of Greenland rose above freezing for the first time since 1889, raising questions about what led to the unusual melt episode. Now, a new CIRES-led analysis shows that some of the same weather and climate factors were at play in both 1889 and 2012: heat waves thousands of miles upwind in North America, higher-than-average ocean surface temperatures south of Greenland and atmospheric rivers of warm, moist air that streamed toward Greenland’s west coast.

“These rare melt events on the highest elevations of Greenland require an unusual coincidence of factors. Understanding how they come together may help us better forecast the future of Greenland’s ice and snow,” said William Neff, a Fellow at CIRES (NOAA’s Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder). Neff is lead author of the new analysis, accepted for publication in the American Geophysical Union’s Journal of Geophysical Research.

Neff and colleagues at CIRES, NOAA’s Earth System Research Laboratory and Scripps Institution of Oceanography at the University of California San Diego began digging into the underlying reasons for Greenland’s extreme melt year after another research project showed that warm air and thin clouds were key to the 2012 warmth and melt. To figure out where the warm air and clouds came from, the scientists started with satellite observations of moisture in the air over the Atlantic Ocean, looking for atmospheric rivers. Atmospheric rivers are narrow filaments of water vapor in the atmosphere that can stream significant amounts of moisture northward in the midlatitudes.

The researchers also studied sea-surface temperatures, which might have influenced the temperature and moisture content of air moving toward Greenland. And to better understand atmospheric and oceanic conditions back in 1889, the research team drew on data in the 20th Century Reanalysis, a sophisticated computer reconstruction of the weather going back to 1871.

Neff and his colleagues found that several key factors conspired to melt Greenland’s surface in both 1889 and 2012:

First, heat waves and drought gripped North American regions upwind of Greenland. In the summer of 2012, temperatures over the mid-to-eastern United States were about 15 degrees Fahrenheit hotter than normal, and a persistent drought plagued the Midwest. In the summer of 1889, temperatures south of Hudson Bay, in the Upper Midwest and over the Rocky Mountains rose in heat waves as much as 15-20 degrees Fahrenheit higher than average, and a severe drought stretched across the northwestern and Upper Midwest states. During periods of melt in both 2012 and 1889, back-trajectory analyses from Greenland showed that incoming air had originated in those unseasonably warm areas upwind—so that air was already warm.

Second, in both years, the ocean surface temperatures south of Greenland were higher than average: by about 2 degrees Fahrenheit in 1889 and nearly 4 degrees in 2012. In both years, that extra warmth came from a natural “oscillation” that periodically seesaws temperatures in the northwest Atlantic Ocean. Air flowing toward Greenland over warmer oceans would have picked up extra warmth and moisture.

Finally, wind and pressure patterns in North America in both years were ideal for steering atmospheric rivers of relatively warm, moist air up along the west coast of Greenland and then over the ice sheet. “These distortions of the jet stream must happen in just the right place to direct atmospheric rivers toward Greenland,” Neff said. “That may be one reason extreme melt events there have been relatively rare.”

Neff and his colleagues found intriguing evidence that a fourth factor—soot from intense U.S. wildfires swept up toward Greenland and deposited on the snow—may have played a role in 1889. Other researchers have found significant deposits of soot in ice core records from the summer of 1889; when darkened by soot or “black carbon,” snow and ice can melt faster. In 1889, Major John Wesley Powell, then director of the U.S. Geological Survey, traveled by train through the northern Rockies during the fire season and later reported to Congress, “The fires in the mountains created such a smoke that the whole country was enveloped by it and hidden from view.”

“Better understanding how factors that can occur naturally, such as long-term droughts or short-term atmospheric rivers, combine to produce an extreme event, such as Greenland’s melt, can help researchers better explain and forecast these events,” said co-author Gilbert Compo, a CIRES scientist working at ESRL. “This is especially important because we expect climate change  to continue to warm the oceans and warm and moisten the atmosphere, raising the possibility of more frequent melt episodes.”

Authors of “Continental heat anomalies and the extreme melting of the Greenland ice surface in 2012 and 1889,” published in the Journal of Geophysical Research: Atmospheres, are: William Neff and Gilbert Compo (CIRES and NOAA ESRL); F. Martin Ralph (UC San Diego, Scripps Institution of Oceanography Center for Western Weather and Water Extremes); and Matthew D. Shupe (CIRES and NOAA ESRL).

CIRES is a partnership of NOAA and CU Boulder.



  • Animations: Atmospheric river events on July 5,1889 and July 9, 2012 swept warm, moist air up toward Greenland’s west coast, contributing to extreme melt that year swept warm, moist air up toward Greenland’s west coast, contributing to extreme melt events both years. Credit: Don Murray, CIRES/NOAA.
  • Still images depicting 1889 and 2012 atmospheric river events are on our Flickr page. Credit: Don Murray, CIRES/NOAA.