Posts tagged INSTAAR
Climate change early warning system called for
Dec 3rd
A new National Research Council report calls for the development of an early warning system that could help society better anticipate sudden changes resulting from climate change and their impacts on society, says a University of Colorado Boulder faculty member who chaired the committee that produced the report.
Climate change has increased concern over possible large and rapid changes in the physical climate system, including Earth’s atmosphere, land surfaces and oceans, said Professor James White of CU-Boulder’s Institute of Arctic and Alpine Research and the chair of the National Research Council committee. Some abrupt changes and impacts already underway – including the loss of Arctic sea ice and increases in the extinction rates of marine and terrestrial species – and others could occur within a few decades or even years, said the committee.
“Research has helped us begin to distinguish more imminent threats from those that are less likely to happen this century,” said White, also a CU-Boulder professor in geological sciences. “Evaluating climate changes and impacts in terms of their potential magnitude and the likelihood they will occur will help policymakers and communities make informed decisions about how to prepare for or adapt to them.”
Other scenarios, such as the destabilization of the west Antarctic ice sheet, have potentially major consequences, but the probability of these changes occurring within the next century is not well understood, highlighting the need for more research, according to the committee.
In some cases, scientific understanding has progressed enough to determine whether certain high-impact climate changes are likely to happen within the next century. The report notes that a shutdown in the Atlantic Ocean circulation patterns or a rapid release of methane from high-latitude permafrost or undersea ice are now known to be unlikely this century, although these potential abrupt changes are still worrisome over longer time horizons.
But even changes in the physical climate system that happen gradually over many decades or centuries can cause abrupt ecological or socio-economic change once a “tipping point” is reached, the report adds. Relatively slow global sea-level rise could directly affect local infrastructure such as roads, airports, pipelines or subway systems if a sea wall or levee is breached. And slight increases in ocean acidity or surface temperatures could cross thresholds beyond which many species cannot survive, leading to rapid and irreversible changes in ecosystems that contribute to extinction events.
Further scientific research and enhanced monitoring of the climate, ecosystems and social systems may be able to provide information that a tipping point is imminent, allowing time for adaptation or possibly mitigation, or that a tipping point has recently occurred, the report says.
“Right now we don’t know what many of these thresholds are,” White said. “But with better information, we will be able to anticipate some major changes before they occur and help reduce the potential consequences.” The report identifies several research needs, such as identifying keystone species whose population decline due to an abrupt change would have cascading effects on ecosystems and ultimately on human provisions such as food supply.
If society hopes to anticipate tipping points in natural and human systems, an early warning system for abrupt changes needs to be developed, the report says. An effective system would need to include careful and vigilant monitoring, taking advantage of existing land and satellite systems and modifying them if necessary, or designing and implementing new systems when feasible. It would also need to be flexible and adaptive, regularly conducting and alternating between data collection, model testing and model predictions that suggest future data needs.
The study was sponsored by the National Oceanic and Atmospheric Administration, National Science Foundation, U.S. intelligence community, and the National Academies. The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies. They are private, independent nonprofit institutions that provide science, technology, and health policy advice under a congressional charter granted to NAS in 1863. The National Research Council is the principal operating agency of the National Academy of Sciences and the National Academy of Engineering.
For more information and a copy of the report visit http://national-academies.org. For more information on INSTAAR visithttp://instaar.colorado.edu.
CU researchers say deep ice cores show past Greenland warm period may be ‘road map’ for continued warming of planet
Jan 23rd
A new study by an international team of scientists analyzing ice cores from the Greenland ice sheet going back in time more than 100,000 years indicates the last interglacial period may be a good analog for where the planet is headed in terms of increasing greenhouse gases and rising temperatures.
The new results from the NEEM deep ice core drilling project led by the University of Copenhagen and involving the University of Colorado Boulder show that between 130,000 and 115,000 years ago during the Eemian interglacial period, the climate in north Greenland rose to about 14 degrees Fahrenheit warmer than today. Despite the strong warming signal during the Eemian — a period when the seas were roughly 15 to 25 feet higher than today — the surface of the north Greenland ice sheet near the NEEM facility was only a few hundred yards lower than it is today, an indication to scientists it contributed less than half of the total sea rise at the time.
Greenland ice burg
The NEEM project involves 300 scientists and students from 14 countries and is led by Professor Dorthe Dahl-Jensen, director of the University of Copenhagen’s Centre of Ice and Climate. CU-Boulder geological sciences professor and ice core expert Jim White is the lead U.S. investigator on the project. The National Science Foundation’s Division of Polar Programs funded the U.S. portion of the effort.
The new Nature findings showed that about 128,000 years ago, the surface elevation of ice near the NEEM site was more than 650 feet higher than present but the ice was starting to thin by about 2 inches per year. Between about 122,000 and 115,000 years ago, Greenland’s surface elevation remained stable at roughly 425 feet below the present level. Calculations indicate Greenland’s ice sheet volume was reduced by no more than 25 percent between 128,000 years ago and 122,000 years ago, said White.
A paper on the subject was published in the Jan. 24 issue of Nature.
“When we calculated how much ice melt from Greenland was contributing to global sea rise in the Eemian, we knew a large part of the sea rise back then must have come from Antarctica,” said White, director of CU-Boulder’s Institute of Arctic and Alpine Research. “A lot of us had been leaning in that direction for some time, but we now have evidence that confirms that the West Antarctic ice sheet was a dynamic and crucial player in global sea rise during the last interglacial period.”
Dahl-Jensen said the loss of ice mass on the Greenland ice sheet in the early part of the Eemian was likely similar to changes seen there by climate scientists in the past 10 years. Other studies have shown the temperatures above Greenland have been rising five times faster than the average global temperatures in recent years, and that Greenland has been losing more than 200 million tons of ice annually since 2003. The Greenland ice loss study was led by former CU-Boulder scientist Isabella Velicogna, who is currently a faculty member at the University of California, Irvine.
The intense melt in the vicinity of NEEM during the warm Eemian period was seen in the ice cores as layers of re-frozen meltwater. Such melt events during the last glacial period were rare by comparison, showing that the surface temperatures at the NEEM site were in a cold, nearly constant state back then. But on July 12, 2012, satellite images from NASA indicated 97 percent of Greenland’s ice sheet surface had thawed as a result of warming temperatures.
“We were quite shocked by the warm surface temperatures observed at the NEEM ice camp in July 2012,” said Dahl-Jensen. “It was raining at the top of the Greenland ice sheet, and just as during the Eemian period, meltwater formed subsurface ice layers. While this was an extreme event, the present warming over Greenland makes surface melt more likely, and the predicted warming over Greenland in the next 50-100 years will very likely be so strong that we will potentially have Eemian-like climate conditions.”
The Greenland ice core layers — formed over millennia by compressed snow — are being studied in detail using a suite of measurements, including stable water isotope analysis that reveals information about temperature and greenhouse gas levels and moisture changes back in time. Lasers are used to measure the water stable isotopes and atmospheric gas bubbles trapped in the ice cores to better understand past variations in climate on an annual basis — similar in some ways to a tree-ring record.
The results from the Nature study provide scientists with a “road map” of sorts to show where a warming Earth is headed in the future, said White. Of the nine hottest years on Earth on record, eight have come since the year 2000. In 2007 the Intergovernmental Panel on Climate Change concluded that temperatures on Earth could climb by as much as 11 degrees F by 2100.
Greenland glacier grooves
Increasing amounts of carbon dioxide in the atmosphere from sources like vehicle exhaust and industrial pollution — which have risen from about 280 parts per million at the onset of the Industrial Revolution to 391 parts per million today — are helping to raise temperatures on Earth, with no end in sight, said White.
“Unfortunately, we have reached a point where there is so much carbon dioxide in the atmosphere it’s going to be difficult for us to further limit our impact on the planet,” White said. “Our kids and grandkids are definitely going to look back and shake their heads at the inaction of this country’s generation. We are burning the lion’s share of oil and natural gas to benefit our lifestyle, and punting the responsibility for it.”
In the past, Earth’s journey into and out of glacial periods is thought to be due in large part to variations in its orbit, tilt and rotation that change the amount of solar energy delivered to the planet, he said. But the anthropogenic warming on Earth today could override such episodic changes, perhaps even staving off an ice age, White said.
While three previous ice cores drilled in Greenland in the last 20 years recovered ice from the Eemian, the deepest layers were compressed and folded, making the data difficult to interpret. Although there was some folding of the lowest ice layers in the NEEM core, sophisticated ice-penetrating radar helped scientists sort out and interpret the individual layers to paint an accurate picture of the warming of Earth’s Northern Hemisphere as it emerged from the previous ice age, White said.
In addition to White, other CU-Boulder co-authors on the NEEM paper include INSTAAR scientist Bruce Vaughn and graduate student Tyler Jones of INSTAAR and CU-Boulder’s Environmental Studies Program.
“It’s a challenge being on the ice sheet, because we are out of our comfort zones and are working long, physical hours in an environment that is extremely cold and where the sun never sets,” Jones said. “Being a member of the research team allowed me to understand the ice core recovery process and the science behind it in terms of learning more about past climates and the implications for future climate change.”
Other nations involved in NEEM include Belgium, Canada, France, Germany, Iceland, Japan, Korea, the Netherlands, Sweden, Switzerland and the United Kingdom. Other U.S. institutions involved in the effort include Oregon State University, Penn State, the University of California, San Diego and Dartmouth College.
For more information on INSTAAR go to http://instaar.colorado.edu/. Additional information, photos and videos on NEEM can be found at http://www.neem.ku.dk.
A video and a slide show on the project will be available on the CU-Boulder news site by clicking on the story headline at http://www.colorado.edu/news.
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CU scientists study high-Asian snowpack for GW clues
Dec 7th
USAID, CU-BOULDER PARTNER TO STUDY
WATER RESOURCES IN ASIA MOUNTAINS
WATER RESOURCES IN ASIA MOUNTAINS
A University of Colorado Boulder team is partnering with the United States Agency for International Development to assess snow and glacier contributions to water resources originating in the high mountains of Asia that straddle 10 countries.
Richard Armstrong and Mark Williams, the two faculty members leading the four-year study, said the aim is to provide a comprehensive and systematic assessment of freshwater resources in the so-called “High Asia” region, which encompasses five mountain ranges and watersheds totaling roughly 1 million square miles. The area under study is roughly equal to one-third of the contiguous United States.
This assessment will be crucial in helping to forecast the future availability and vulnerability of water resources in the region, beginning with accurate assessments of the distinct, separate contributions to river discharge from melting glacier ice and seasonal snow. Such data ultimately will provide a better understanding of the timing and volume of runoff in the face of climate change, said the CU-Boulder researchers.
The High Asia mountains funnel water into such major river basins as the Ganges, Brahmaputra, Indus, Amu Darya and Syr Darya. The High Asian mountain ranges under study include the Himalaya, Karkoram, Hindu Kush, Pamir and Tien Shan. The mountain ranges straddle Bhutan, Nepal, China, India, Pakistan, Afghanistan, Kazakhstan, Uzbekistan, Kyrgyzstan and Tajikistan.
Through the partnership, scientists and students within the 10 countries will carry out collaborative research with CU-Boulder scientists. The project also will support satellite data processing by CU-Boulder staff and trainings for local institutions and observers within the study area to collect water and precipitation samples for the project.
While about one-third of the world’s population depends to some degree on fresh water within the High Asia hydrological system, not enough data exists on river and stream flows and the contribution of seasonal snow and glacier melt to paint an accurate picture of the water resources there, said Armstrong, a senior research scientist at CU-Boulder’s National Snow and Ice Data Center, or NSIDC. ”
The team requires an accurate quantitative portrait of each major river basin and sub-basin in High Asia. The Indus River, for example, which is fed by waterways from the Himalaya, Karakorum and Hindu Kush mountain ranges, comes together at the city of Besham, Pakistan, “where it immediately turns into the largest irrigation system in the world,” said Williams. “The sources of water in High Asia feeding the major foothill regions where most of the people live are really the crux of this study.”
Armstrong said there is a lot of misinformation in the public arena regarding glaciers, including reports that glaciers in the Himalaya are receding faster than anywhere else in the world and, if this rapid melting continues, rivers are on track to first flood and then dry up. “Those reports simply are not true,” Armstrong said.
USAID is an independent United States government agency that provides economic, development and humanitarian assistance around the world in support of the foreign policy goals of the United States.
“USAID wants to know how the High Asia water resources affect local populations,” said Armstrong, also a fellow at the CU-headquartered Cooperative Institute for Research in Environmental Sciences. “They are looking at this challenge from a sustainability perspective, including what is going to happen to rivers like the Indus and the Brahmaputra in the next 20 years.”
The researchers will use remote-sensing satellite data from NASA, the European Space Agency and the Japanese Space Agency to develop time-series maps of seasonal snowfall amounts and recent changes in glacier extent, said Williams, a fellow at CU-Boulder’s Institute of Arctic and Alpine Research and a CU-Boulder geography professor. They also will use local meteorological and river discharge data from throughout the High Asia study area.
“What’s really driving this study are questions about water security,” said Williams. “There is a lot of international interest in accurate water resource data from the High Asia region and what the water security consequences are, since water conflicts between countries can escalate rapidly. This study should provide answers as to what is real and what is false.”
“Once we have a picture of recent and current conditions, we can go forward and run computer ‘melt models’ based on the temperatures at various elevations, giving us trends in snowmelt and glacier melt by region and time,” said Armstrong. “That’s when we start to come up with water volumes for individual rivers and streams from both melting snow and ice.”
The modeling results will be verified using geochemical and water isotope “tracer” techniques developed at CU that allow researchers to follow water as it courses through mountain landscapes. Previous studies by Williams and his research group showed high mountain groundwater in Colorado dominated by snowmelt can be locked underground for decades before emerging into downstream waterways. “These isotopic and geochemical measurements provide unique fingerprints, allowing a CSI-like approach to tracing water sources,” said Williams.
Critical to the project is the university’s expertise in remote sensing research through NSIDC — including assessing changes in Earth’s snow and ice cover — and INSTAAR’s research on the physical, chemical and biological processes in “critical zones,” which are the areas between treetops and groundwater. INSTAAR administers both the Long-Term Ecological Research site at Niwot Ridge west of Boulder and the Critical Zone Observatory project in the Boulder Creek watershed for the National Science Foundation.
One of the biggest project challenges will be to obtain data from some of the most remote regions on Earth, said Williams. The water, rain and snow samples collected by collaborators within the study area will be sent back to CU-Boulder for analysis.
The research will bring together scientists and government officials in the countries of High Asia to coordinate and compare results on what part of river flows come from glaciers and seasonal snow. This sharing of information is important because the rivers of Asia can cross several country borders. USAID support will contribute to the research and coordination and CU-Boulder will make its archived and new data on snow and ice easily available to all the countries and their citizens.
The CU team will hire Asian project managers and collaborate with research scientists affiliated with various Asian institutes. “We already have some good scientific contacts in the region, people we know who are reliable and who can deliver,” said Armstrong.
A number of CU undergraduate and graduate students will be involved in the study and support will be available to Asian students by way of the funding provided to Asian project partners.
“One of the main project goals is to transfer scientific understanding to people in the region who can continue these measurements and analysis once the USAID project is finished,” said Armstrong. “The idea is to provide the local population with the information they need to make decisions that will increase sustainability as land use and climate change.
