Tech & Science
Technology and Science news from Boulder, Colorado
CU-NOAA study shows summer climate change, mostly warming
Nov 15th
“It is the first time that we show on a local scale that there are significant changes in summer temperatures,” said lead author CIRES scientist Irina Mahlstein. “This result shows us that we are experiencing a new summer climate regime in some regions.”
The technique, which reveals location-by-location temperature changes rather than global averages, could yield valuable insights into changes in ecosystems on a regional scale. Because the methodology relies on detecting temperatures outside the expected norm, it is more relevant to understand changes to the animal and plant life of a particular region, which scientists would expect to show sensitivity to changes that lie outside of normal variability.
“If the summers are actually significantly different from the way that they used to be, it could affect ecosystems,” said Mahlstein, who works in the Chemical Sciences Division of the National Oceanic and Atmospheric Administration’s Earth System Research Laboratory.
To identify potential temperature changes, the team used climate observations recorded from 1920 to 2010 from around the globe. The scientists termed the 30-year interval from 1920 to 1949 the “base period,” and then compared the base period to other 30-year test intervals starting every 10 years since 1930.
The comparison used statistics to assess whether the test interval differed from the base period beyond what would be expected due to yearly temperature variability for that geographical area.
Their analysis found that some changes began to appear as early as the 1960s, and the observed changes were more prevalent in tropical areas. In these regions, temperatures varied little throughout the years, so the scientists could more easily detect any changes that did occur, Mahlstein said.
The scientists found significant summer temperature changes in 40 percent of tropical areas and 20 percent of higher-latitude areas. In the majority of cases, the researchers observed warming summer temperatures, but in some cases they observed cooling summer temperatures.
“This study has applied a new approach to the question, ‘Has the temperature changed in local areas?’ ” Mahlstein said. The study is in press in the journal Geophysical Research Letters, a publication of the American Geophysical Union.
The study’s findings are consistent with other approaches used to answer the same question, such as modeling and analysis of trends, Mahlstein said. But this technique uses only observed data to come to the same result. “Looking at the graphs of our results, you can visibly see how things are changing,” she said.
In particular the scientists were able to look at the earlier time periods, note the temperature extremes, and observe that those values became more frequent in the later time periods. “You see how the extreme events of the past have become a normal event,” Mahlstein said.
The scientists used 90 years of data for their study, a little more than the average lifespan of a human being. So if inhabitants of those areas believe that summers have changed since they were younger, they can be confident it is not a figment of their imagination.
“We can actually say that these changes have happened in the lifetime of a person,” Mahlstein said.
Co-authors on the study were Gabriele Hegerl from the University of Edinburgh in Scotland and Susan Solomon from Massachusetts Institute of Technology.
CIRES is a joint institute of CU-Boulder and NOAA.
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Frankenstorms are fueled by global warming
Oct 30th
Global Warming Raises Sea Levels, Alters Jet Stream, Makes Storms Stronger
SAN FRANCISCO— As America copes with the destruction caused by Hurricane Sandy, scientists with the Center for Biological Diversity are urging the Environmental Protection Agency to use the Clean Air Act to take emergency action against climate change. Global warming creates a “superstorm triple whammy” that helps turn nasty weather into a nightmare of killer winds and devastating storm surges.
“The terrifying truth is that America faces a future full of Frankenstorms,” said Shaye Wolf, Ph.D., the Center’s climate science director. “Climate change raises sea levels and supersizes storms. The threat of killer winds and crushing storm surges will grow by the year unless we get serious about tackling greenhouse gas pollution.”
Here’s how scientists say climate change feeds the superstorm triple whammy:
1. Global warming loads storms with more energy and more rainfall. A new study in the Proceedings of the National Academy of Sciences found that Katrina-magnitude Atlantic hurricanes have been twice as likely in warm years compared with cold years. In warm years hotter ocean temperatures add energy to storms and warmer air holds more moisture, causing storms to dump more rainfall. Global ocean temperatures hit their second-highest level on record in September, according to the National Oceanic and Atmospheric Administration.
2. Storm surge rides on higher sea levels, so more coastline floods during storms. In the northeastern United States, sea levels are rising three to four times faster than the global average, putting major U.S. cities at increased risk of flooding and storm surges, according to a June 2012 study in Nature Climate Change. The West Coast is not immune: Most of California could experience three or more feet of sea-level rise this century, heightening the risk of coastal flooding.
3. Melting sea ice and accelerating Arctic warming are causing changes in the jet stream that are bringing more extreme weather to the United States. Climate change in the Arctic is destabilizing the jet stream, causing bursts of colder air to drop down farther into the United States. In Sandy’s case, a collision with a cold front acted to turn the hurricane into a superstorm. Recent research, including studies by Georgia Institute of Technology and Rutgers University, has linked Arctic warming to increased risk of a variety of extreme weather events.
Deep and rapid greenhouse gas cuts are needed to reduce extreme weather risk. The Clean Air Act is America’s leading tool for curbing greenhouse gas pollution, and more than three dozen U.S. cities have joined the Center’s Clean Air Cities campaign urging the EPA to use the Clean Air Act to help reduce carbon in our atmosphere to no more than 350 parts per million, the level scientists say is needed to avoid catastrophic climate change.
The Center for Biological Diversity is a national, nonprofit conservation organization with more than 450,000 members and online activists dedicated to the protection of endangered species and wild places.
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CU Boulder researchers uncover new target for cancer research
Oct 25th
Researchers in the two scientists’ laboratories collaborated to find a patch of amino acids that, if blocked by a drug docked onto the chromosome end at this location, may prevent cancerous cells from reproducing. The amino acids at this site are called the “TEL patch” and once modified, the end of the chromosome is unable to recruit the telomerase enzyme, which is necessary for growth of many cancerous cells.
“This is an exciting scientific discovery that gives us a new way of looking at the problem of cancer,” Cech said. “What is amazing is that changing a single amino acid in the TEL patch stops the growth of telomeres. We are a long way from a drug solution for cancer, but this discovery gives us a different, and hopefully more effective, target.”
Cech is the director of the BioFrontiers Institute, a Howard Hughes Medical Investigator and winner of the 1989 Nobel Prize in chemistry.
Co-authors on the study include postdoctoral fellows Jayakrishnan Nandakumar and Ina Weidenfeld; University of Colorado undergraduate student Caitlin Bell; and Howard Hughes Medical Institute Senior Scientist Arthur Zaug.
Telomeres have been studied since the 1970s for their role in cancer. They are constructed of repetitive nucleotide sequences that sit at the ends of our chromosomes like the ribbon tails on a bow. This extra material protects the ends of the chromosomes from deteriorating, or fusing with neighboring chromosome ends. Telomeres are consumed during cell division and, over time, will become shorter and provide less cover for the chromosomes they are protecting. An enzyme called telomerase replenishes telomeres throughout their lifecycles.
Telomerase is the enzyme that keeps cells young. From stem cells to germ cells, telomerase helps cells continue to live and multiply. Too little telomerase produces diseases of bone marrow, lungs and skin. Too much telomerase results in cells that over proliferate and may become “immortal.” As these immortal cells continue to divide and replenish, they build cancerous tumors. Scientists estimate that telomerase activation is a contributor in up to 90 percent of human cancers.
To date, development of cancer therapies has focused on limiting the enzymatic action of telomerase to slow the growth of cancerous cells. With their latest discovery, Cech and Leinwand envision a cancer drug that would lock into the TEL patch at chromosome ends to keep telomerase from binding there. This approach of inhibiting the docking of telomerase may be the elegant solution to the complex problem of cancerous cells. Cech, a biochemist, and Leinwand, a biologist, joined forces to work on their latest solution.
“This work was really made possible by the fact that our labs are so close,” Leinwand said. “My lab was able to provide the cell biology and understanding of genetics, and Tom’s lab allowed us to explore the biochemistry. We have a unique situation at BioFrontiers where labs and people comingle to make discoveries just like this.”
Leinwand is the chief scientific officer of the BioFrontiers Institute and a professor of molecular, cellular and developmental biology.
Researchers at the University of Colorado have a significant history in developing marketable biotechnologies. Cech founded Ribozyme Pharmaceuticals Inc. Leinwand co-founded Myogen with CU professor Michael Bristow, Hiberna and recently launched MyoKardia (http://www.myokardia.com/about.php).
The BioFrontiers Institute is an interdisciplinary institute housed at the Jennie Smoly Caruthers Biotechnology Building at CU-Boulder. The institute is dedicated to training the next generation of interdisciplinary scientists through its IQ Biology Interdisciplinary Quantitative Biology Ph.D. program. For more information about BioFrontiers visithttp://biofrontiers.colorado.edu
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