Climate Change Will Drive Stronger, Smaller Storms in U.S.
December 2, 2016 11:22 AM - Rob Mitchum via Computation Institute
The effects of climate change will likely cause smaller but stronger storms in the United States, according to a new framework for modeling storm behavior developed at the University of Chicago and Argonne National Laboratory. Though storm intensity is expected to increase over today’s levels, the predicted reduction in storm size may alleviate some fears of widespread severe flooding in the future.
The new approach, published today in Journal of Climate, uses new statistical methods to identify and track storm features in both observational weather data and new high-resolution climate modeling simulations. When applied to one simulation of the future effects of elevated atmospheric carbon dioxide, the framework helped clarify a common discrepancy in model forecasts of precipitation changes.
Exploring the fate of the Earth's storehouse of carbon
December 1, 2016 04:41 PM - Tom Rickey via PNNL
A new study predicts that warming temperatures will contribute to the release into the atmosphere of carbon that has long been locked up securely in the coldest reaches of our planet.
Soil and climate expert Katherine Todd-Brown, a scientist at the Department of Energy's Pacific Northwest National Laboratory, is an author of the paper, published in the Dec. 1 issue of the journal Nature, which draws upon data collected through 49 separate field experiments around the world.
The research was led by Thomas Crowther, formerly of Yale and now at the Netherlands Institute of Ecology, and colleague Mark Bradford at Yale. Scientists from more than 30 institutions across the globe, including PNNL, collaborated on the study.
Increasing tornado outbreaks — Is climate change responsible?
December 1, 2016 02:51 PM - Columbia University School of Engineering and Applied Science
Tornadoes and severe thunderstorms kill people and damage property every year. Estimated U.S. insured losses due to severe thunderstorms in the first half of 2016 were $8.5 billion. The largest U.S. impacts of tornadoes result from tornado outbreaks, sequences of tornadoes that occur in close succession. Last spring a research team led by Michael Tippett, associate professor of applied physics and applied mathematics at Columbia Engineering, published a study showing that the average number of tornadoes during outbreaks—large-scale weather events that can last one to three days and span huge regions—has risen since 1954. But they were not sure why.
In a new paper, published December 1 in Science via First Release, the researchers looked at increasing trends in the severity of tornado outbreaks where they measured severity by the number of tornadoes per outbreak. They found that these trends are increasing fastest for the most extreme outbreaks. While they saw changes in meteorological quantities that are consistent with these upward trends, the meteorological trends were not the ones expected under climate change.
Corals much older than previously thought
November 30, 2016 04:21 PM - Sara LaJeunesse via Penn State
Coral genotypes can survive for thousands of years, possibly making them the longest-lived animals in the world, according to researchers at Penn State, the National Marine Fisheries Service and Dial Cordy & Associates.
The team recently determined the ages of elkhorn corals — Acropora palmata — in Florida and the Caribbean and estimated the oldest genotypes to be over 5,000 years old. The results are useful for understanding how corals will respond to current and future environmental change.
Climate models may be overestimating the cooling effect of wildfire aerosols
November 29, 2016 04:32 PM - Mark Dwortzan via Massachusetts Institute of Technology
Whether intentionally set to consume agricultural waste or naturally ignited in forests or peatlands, open-burning fires impact the global climate system in two ways which, to some extent, cancel each other out. On one hand, they generate a significant fraction of the world’s carbon dioxide emissions, which drive up the average global surface temperature. On the other hand, they produce atmospheric aerosols, organic carbon, black carbon, and sulfate-bearing particulates that can lower that temperature either directly, by reflecting sunlight skyward, or indirectly, by increasing the reflectivity of clouds. Because wildfire aerosols play a key role in determining the future of the planet’s temperature and precipitation patterns, it’s crucial that today’s climate models — upon which energy and climate policymaking depend — accurately represent their impact on the climate system.
With Climate Change, Not All Wildlife Population Shifts Are Predictable
November 29, 2016 09:06 AM - Janet Lathrop via University of Massachusetts at Amherst
Wildlife ecologists who study the effects of climate change assume, with support from several studies, that warming temperatures caused by climate change are forcing animals to move either northward or upslope on mountainsides to stay within their natural climate conditions.
But a new study of lowland and higher-mountain bird species by wildlife ecologists Bill DeLuca and David King at the University of Massachusetts Amherst now reports an unexpected and “unprecedented” inconsistency in such shifts. The majority of the mountain bird community responded against expectation and shifted downslope despite warming trends in the mountains. They say the result “highlights the need for caution when applying conventional expectations to species’ responses to climate change.”
West Antarctic ice shelf breaking up from the inside out
November 28, 2016 11:07 AM - Pam Frost Gorder via Ohio State University
A key glacier in Antarctica is breaking apart from the inside out, suggesting that the ocean is weakening ice on the edges of the continent.
The Pine Island Glacier, part of the ice shelf that bounds the West Antarctic Ice Sheet, is one of two glaciers that researchers believe are most likely to undergo rapid retreat, bringing more ice from the interior of the ice sheet to the ocean, where its melting would flood coastlines around the world.
A nearly 225-square-mile iceberg broke off from the glacier in 2015, but it wasn’t until Ohio State University researchers were testing some new image-processing software that they noticed something strange in satellite images taken before the event.
102 Million Trees Have Died in California's Drought
November 25, 2016 02:42 PM - EcoWatch via , Care2
California’s six years of drought has left 102 million dead trees across 7.7 million acres of forest in its wake, the U.S. Forest Service (USFS) announced following an aerial survey. If that is not horrendous enough, 62 million trees died in the year 2016 alone—an increase of more than 100 percent compared to 2015.
“The scale of die-off in California is unprecedented in our modern history,” Randy Moore, a forester for the U.S. Forest Service, told the Los Angeles Times, adding that trees are dying “at a rate much quicker than we thought.”
Study Shows Climate Affecting Avian Breeding Habits
November 25, 2016 12:05 PM - Kathleen Tuck via Boise State University
Milder winters have led to earlier growing seasons and noticeable effects on the breeding habits of some predatory birds, according to research by Boise State biologists Shawn Smith and Julie Heath, in collaboration with Karen Steenhof, and The Peregrine Fund’s Christopher McClure. Their work was recently published in the Journal of Animal Ecology under the title “Earlier nesting by generalist predatory bird is associated with human responses to climate change.”
Saharan dust in the wind
November 24, 2016 10:39 AM - Jennifer Chu via MIT
Every year, trade winds over the Sahara Desert sweep up huge plumes of mineral dust, transporting hundreds of teragrams — enough to fill 10 million dump trucks — across North Africa and over the Atlantic Ocean. This dust can be blown for thousands of kilometers and settle in places as far away as Florida and the Bahamas.
The Sahara is the largest source of windblown dust to the Earth’s atmosphere. But researchers from MIT, Yale University, and elsewhere now report that the African plume was far less dusty between 5,000 and 11,000 years ago, containing only half the amount of dust that is transported today.