Climate: New study helps illustrate how CO2 affects Arctic

Posted on May 12, 2013 by Bob Berwyn
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A new study suggests the Earth’s climate system is more sensitive to CO2 changes than assumed by the IPCC’s 2007 global climate report.

Researchers establish longest regional climate record using sediment cores from an Arctic Lake that’s been undisturbed for 3.6 million years

By Summit Voice

FRISCO — Sediment cores from a crater lake in Siberia are helping scientists understand how varying concentrations of atmospheric carbon dioxide affect the Arctic climate.

The sediment cores help establish the longest continuous climate record from the region, showing that the Arctic was a very warm place during a period about 3.5 to 2 million years ago, when CO2 levels were similar to today’s.

The research leads to the conclusion that even small fluctuations in CO2 can result in big changes in the Arctic, according to Julie Brigham-Grette, of the University of Massachusetts Amherst.

The study indicates Arctic may have been much warmer during that era than other climate studies suggest, and that the planet’s climate system is probably more sensitive to CO2 levels than assumed in the 2007 report of the Intergovernmental Panel on Climate Change. (more…)

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Climate: Atmospheric CO2 reaches 400 ppm

Posted on May 11, 2013 by Bob Berwyn

Concentration will wane from seasonal high point, but long-term trend is up

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Mauna Loa. Photo courtesy USGS.

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Carbon dioxide in the atmosphere this week reached a level last recorded 2 to 5 million years ago.

By Summit Voice

FRISCO — Climate scientists have been closely tracking atmospheric carbon dioxide levels for a long time, but this week, the colorless, odorless gas made big headlines.

An atmospheric observatory on Mauna Loa for the first time measured daily concentrations of CO2 at slightly above 400 parts per million, a dubious milestone which, better than any other number, captures the extent to which we are changing the world. (more…)

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Climate: How fast will Greenland’s glaciers melt?

Posted on May 8, 2013 by Bob Berwyn

Study shows topography is a key factor in controlling ice flow

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A giant iceberg that broke off the terminus of Greenland’s Petermann Glacier in July 2012 moves down the fjord toward the Nares Strait. Image courtesy NASA Earth Observatory.

A new study helps pinpoint how many icebergs may from as Greenland's glaciers are subjected to global warming. Photo courtesy British Antarctic Survey.

A new study helps pinpoint how many icebergs may from as Greenland’s glaciers are subjected to global warming. Photo courtesy British Antarctic Survey.

By Bob Berwyn

FRISCO — Greenland’s swift outflow glaciers are sensitive to warming air and ocean temperatures, but a new study published in the journal Nature indicates that the recent acceleration of glacial flow isn’t continuing at a linear rate.

The shape of the ground and seafloor beneath the glaciers is crucial in determining how they respond to climate change — how fast they move and how much they will contribute to sea level rise in coming decades.

“What we are saying is that we shouldn’t extrapolate the rate of the last 10 years into the future … If  you study these glaciers separately, they show different behavior,” said lead author Dr. Faezeh Nick, of the Université Libre de Bruxelles, describing the work done on the Petermann, Kangerdlugssuaq, Helheim and Jakobshavn Isbræ glaciers. Together, they drain about 22 percent of the Greenland ice sheet. (more…)

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The subnivium, a secret world beneath the snow, is at risk from global warming

Posted on May 8, 2013 by Bob Berwyn

Declining spring snowcover will impact plants and animals use deep snow cover as a refuge from winter cold

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Spring snow cover in the northern hemisphere is in decline. Graphic courtesy Rutgers Global Snow Lab.

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Melting snow reveals the subniveal world.

By Bob Berwyn

FRISCO — Beneath winter’s deep snows there is a secret world of frozen insects and amphibians in quasi-hibernation, where small mammals scoot about eating bugs and fungi. It’s an ecoogical world that’s mostly invisible but functions as a critical part of larger ecosystems. The subnivium, as scientists have dubbed it, is now at risk from global warming.

Since 1970, snow cover in the Northern Hemisphere has declined by as much as 3.2 million square kilometers during the critical spring months of March and April. Maximum snow cover has shifted from February to January and spring melt has accelerated by almost two weeks, according to a team of university researchers who set out to discover some of the ecological impacts of the loss of snow cover. Visit the Rutgers Global Snow Lab for more details on snow cover. (more…)

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WMO: Global warming drives more climate disruption

Posted on May 6, 2013 by Bob Berwyn
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Earth is warming inexorably. Satellite image via NASA’s Blue Marble collection.

World’s top meteorological body concerned about global trends

By Summit Voice

FRISCO —Climate-sensitive economic sectors like agriculture and energy are already feeling the pinch of more extreme fluctuations in the weather, driven by global climate change, according to the World Meteorological Organization, which released its annual climate statement for 2012 last week.

“It is vital that we continue to invest in the observations and research that will improve our knowledge about climate variability and climate change,” said WMO Secretary-General Michel Jarraud. “We need to understand how much of the extra heat captured by greenhouse gases is being stored in the oceans and the consequences this brings in terms of ocean acidification and other impacts,” Jarraud said in the statement. (more…)

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Global warming: More hurricanes in Hawaii?

Posted on May 6, 2013 by Bob Berwyn
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Hurricane Iniki reached Kauai in September 1992 as a Category 4 storm, with winds up to 140 mph.

Study projects two to three times as many storms by the end of the century

By Summit Voice

SUMMIT COUNTY — Large scale shifts in hemispheric circulation patterns and ocean temperatures are likely to steer more hurricanes toward the Hawaiian Islands in coming decades.

A poleward shift of the subtropical jet stream and warmer temperatures over the equatorial central Pacific will combine to make the storms two to three times as likely by the last quarter of the century, according to scientists with the International Pacific Research Center, University of Hawaii at Manoa. (more…)

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NASA study solidifies evidence that global warming will cause more droughts and more extreme rainfall

Posted on May 4, 2013 by Bob Berwyn
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Some parts of the world could see more intense monsoon rainfall as the world warms up. Bob Berwyn photo.

Latest modeling offers a nuanced picture of rainfall changes

By Summit Voice

FRISCO — NASA scientists say one of their latest modeling studies supports previous research suggesting that global warming will intensify rainfall and drought.

An analysis of computer simulations from 14 climate models indicates wet regions of the world, such as the equatorial Pacific Ocean and Asian monsoon regions, will see increases in heavy precipitation because of warming resulting from projected increases in carbon dioxide levels. Arid land areas outside the tropics and many regions with moderate rainfall could become drier.

“In response to carbon dioxide-induced warming, the global water cycle undergoes a gigantic competition for moisture resulting in a global pattern of increased heavy rain, decreased moderate rain, and prolonged droughts in certain regions,” said William Lau of NASA’s Goddard Space Flight Center in Greenbelt, Md., and lead author of the study. (more…)

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NASA mission targets more accurate snowpack data

Posted on May 4, 2013 by Bob Berwyn
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NASA Airborne Snow Observatory measurements of snow water equivalent (top image) and snow albedo, or reflectivity (bottom image) for the Tuolumne River Basin in California’s Sierra Nevada on April 21, 2013. The snow water equivalent measured the total water contained as snow in the basin on that date at 375 million cubic meters, or enough to fill the Rose Bowl about 1,180 times. The albedo map expresses the percentage of sunlight reflected back to space by the snow. The lower the albedo, the faster the snowmelt rate and runoff. Image credit: NASA/JPL-Caltech.

Aerial surveys with high-tech instruments will create detailed snow maps, yielding better runoff forecasts

FRISCO — Data from an ambitious new NASA aerial program could help resource managers get a jump on global warming, with more precise and timely snowpack measurements.

By Summit Voice

NASA’s Airborne Snow Observatory began it’s three-year demonstration mission in April, with weekly flights over the Tuolumne River Basin in California’s Sierra Nevada and monthly flights over Colorado’s Uncompahgre River Basin. Scientists involved in the program hope to start covering the entire Upper Colorado River Basin.

The data is already paying off for power companies and water managers, who can use real-time updates to allocate water resources more efficiently, for storage, irrigation and municipal supplies.

Most snowpack measurements are currently collected via ground-based surveys and from automated SNOTEL sites. Airborne mapping can cover more ground and gather data from areas without observation stations, resulting in more accurate forecasts. (more…)

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Climate: Study finds plant ‘emissions’ counteract small percentage of global warming

Posted on May 2, 2013 by Bob Berwyn
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Plant-based aerosols seen as factor in global warming puzzle. Bob Berwyn photo.

Regional effects of plant-based aerosol formation could be significant

By Summit Voice

FRISCO — A warmer climate will spur plants to release more gases that help form clouds, counteracting about 1 percent of effect of heat-trapping greenhouse gases, according to research by IIASA and the University of Helsinki.

On a regional scale, the effect is more significant, the scientists concluded, finding that in places like Finland, Siberia, and Canada, the negative feedback loop could counteract  up to 30 percent of warming in more rural, forested areas where anthropogenic emissions of aerosols were much lower in comparison to the natural aerosols. (more…)

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Global warming: New report eyes significant Arctic threats

Posted on April 29, 2013 by Bob Berwyn

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Coordinated planning needed to address major environmental and social challenges

By Summit Voice

SUMMIT COUNTY — Increased coastal erosion, bigger and more destructive tundra fires and caribou starvation are just a few of the impacts anticipated in a  major new report on the Arctic.

The report, compiled by an interagency working group, calls for an integrated management strategy for the rapidly changing region, using a coordinated approach that uses the best available science to integrate cultural, environmental and economic factors in decision-making about development and conservation.

“This report chronicles how Arctic residents are dealing with rapid, climate change-induced impacts on their resources and traditional ways of life at the same time that new economic activity and opportunities are emerging — notably oil and gas, marine transportation, tourism and mining,” Deputy Interior Secretary David Hayes. (more…)

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