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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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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Biodiversity: The complex web of Arctic life

Posted on April 28, 2013 by Bob Berwyn
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Pikas in the Arctic may rely on caterpillars to fertilize grass. Photo courtesy Kim Fenske.

Biologists document biological connection between pikas and Arctic caterpillars

By Summit Voice

SUMMIT COUNTY — With the Arctic warming up at a rapid pace, there’s a good chance that the ecosystems will change drastically at all levels. University of Alberta Researchers tracking those changes said they were surprised when they discovered a previously unknown relationship between pikas and Arctic caterpillars.

Biologist Isabel C. Barrio analyzed how two herbivores, caterpillars and pikas, competed for scarce vegetation in alpine areas of the southwest Yukon. The caterpillars come out of their winter cocoons and start consuming vegetation soon after the snow melts in June.

Weeks later, the pika starts gathering and storing food in its winter den. For the experiment, Barrio altered the numbers of caterpillars grazing on small plots of land surrounding pika dens.

“What we found was that the pikas preferred the patches first grazed on by caterpillars,” said Barrio. “We think the caterpillar’s waste acted as a natural fertilizer, making the vegetation richer and more attractive to the pika.” (more…)

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Climate: Are ice-free Arctic summers coming soon?

Posted on April 13, 2013 by Bob Berwyn

Study compares models to estimate a range of dates

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Scientists explore the melting ice of the Arctic. Photo courtesy NOAA.

By Summit Voice

FRISCO— No matter which you slice it, the Arctic Ocean is likely to almost free of summer ice by mid-century, and possibly within the next couple of decades. according to a new study by federal scientists.

By comparing three different predictive models, the researchers came up with a range of dates when most of the Arctic Ocean ice will melt away for at least a couple of months during the northern hemisphere summer.

The most aggressive models, which weigh recent trends more heavily, suggest ice-free conditions could come as soon as 2020. Under a second group of models that rely on weighing the future probability of “extreme” but random ice-melt events, the ice-free date is pushed back to 2030. The most conservative predictions are based on global climate models that use global climate models to forecast atmosphere, ocean, land, and sea ice conditions over time. (more…)

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Climate: Thin, first-year ice now dominates Arctic Ocean

Posted on April 6, 2013 by Bob Berwyn
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The map at top shows the ages of ice in the Arctic at the end of March 2013; the bottom graph shows how the percentage of ice in each age group has changed from 1983 to 2013. Credit: NSIDC courtesy J. Maslanik and M. Tschudi, University of Colorado.

Seasonal shift begins in northern latitudes

By Summit Voice

FRISCO — It’s just the very start of the melt season in the Arctic, but sea ice has already dropped below last year’s level, which ended with a record low extent in September.

In the early April update, the National Snow and Ice Data Center reported that levels of multiyear ice remain extremely low. Satellite data suggests that first-year ice may now cover the North Pole area for the first time since the winter of 2008.

For March, the average extend was about 5.81 million square miles, which is about 274,000 square miles below the 1979 to 2000 average extent, and about 236,000 square miles above the record low for the month, set in 2006. March sea ice extent is declining at a rate of about 2.5 percent each decade, losing about 15,300 square miles per year, (about the size of Maryland and Delaware combined). (more…)

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Climate: Arctic greening to amplify regional warming

Posted on April 2, 2013 by Bob Berwyn

New study suggests large-scale northward shift of forests

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Tundra treeline in Siberia.

By Summit Voice

SUMMIT COUNTY — A massive greening of the Arctic that’s already under way will intensify in the next few decades and speed up the planet’s warming process, according to a new study published this week in Nature Climate Change.

Forested areas in the Arctic could increase by 50 percent, reducing the albedo of the region and speeding up the warming of the Arctic, according to Richard Pearson, lead author on the paper and a research scientist at the American Museum of Natural History’s Center for Biodiversity and Conservation.

“Such widespread redistribution of Arctic vegetation would have impacts that reverberate through the global ecosystem,”  said Pearson, part of a research team including scientists with AT&T Labs-Research, Woods Hole Research Center, Colgate University, Cornell University, and the University of York. (more…)

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Study maps vast areas of new plant growth as global warming reshapes the Arctic

Posted on March 11, 2013 by Bob Berwyn

Decoupling of seasonal events will have unforeseen consequences

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Every climate-change map from the past few decades shows the disproportionate warming in far northern latitudes.

By Summit Voice

SUMMIT COUNTY — Global warming is reshaping the Arctic on vast scale by reducing the temperature differences between seasons and spurring vast areas of new plant growth on more than a third of the northern landscape. The changes cover about 9 million square kilometers, where the Arctic is greening up dramatically, according to a new study published in the journal Natural Climate Change.

“The … increased greenness in the Arctic … is visible on the ground as an increasing abundance of tall shrubs and tree incursions in several locations all over the circumpolar Arctic,” said study co-author Prof. Terry Callaghan of the Royal Swedish Academy of Sciences and the University of Sheffield, UK. He said greening in the adjacent boreal areas is much less conspicuous in North America than in Eurasia. (more…)

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Shell to ‘pause’ Arctic offshore drilling program

Posted on February 27, 2013 by Bob Berwyn
The anchor-handling vessel, the Aiviq, tows the drilling unit Kulluk to a safe harbor location in Kiliuda Bay, Alaska on Jan. 7, 2013. Photo by U.S. Coast Guard Petty Officer 3rd Class Jonathan Klingenberg.

The anchor-handling vessel, the Aiviq, tows the drilling unit Kulluk to a safe harbor location in Kiliuda Bay, Alaska on Jan. 7, 2013. Photo by U.S. Coast Guard Petty Officer 3rd Class Jonathan Klingenberg.

Company still committed to long-term Alaska program

By Summit Voice

FRISCO — After a string of incidents, including failed tests of oil spill containment gear, runaway ships and notices for violations of environmental regulations, Royal Dutch Shell today said it will press the pause button on its Arctic drilling program for a year.

The company said it wants to better prepare its equipment and plans for a resumption of activity at a later stage.

In a press release, Upstream Americas (a Shell subsidiary) director Marvin Odum said, “We’ve made progress in Alaska, but this is a long-term programme that we are pursuing in a safe and measured way. Our decision to pause in 2013 will give us time to ensure the readiness of all our equipment and people following the drilling season in 2012,” Odum said. (more…)

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Climate: Tracking Arctic ecosystem changes

Posted on February 23, 2013 by Bob Berwyn
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An adult female walrus on an ice floe in the Arctic. Photo courtesy USGS.

Five-year project will monitor Bering Sea

By Summit Voice

FRISCO — With a five-year grant from the National Science Foundation, a team of biologists from the University of Maryland Center for Environmental Science’s Chesapeake Biological Laboratory will take an in-depth look at how global warming plays out in the Arctic ecosystems of the Bering Sea.

The two researchers, Jackie Grebmeier and Lee Cooper, have been visiting the area north of Alaska for nearly 30 years, reporting that the biggest changes have come in just the past few years. Last summer marked a record-low for Arctic sea ice extent, and eight of the last ten years have seen the lowest ice coverage on record. (more…)

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What’s the climate tipping point for permafrost?

Posted on February 22, 2013 by Bob Berwyn

Cave study offers clues on temperature threshold

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Global permafrost is a significant factor in the climate-change equation. Map courtesy United Nations Environmental Program.

By Summit Voice

SUMMIT COUNTY — Climate scientists have long been warning that a meltdown of Arctic permafrost will trigger a spike in greenhouse gas emissions as long-frozen organic soils give up their carbon to the atmosphere. What’s not yet clear is how fast and how much of the permafrost will melt, but a new study helps identify a temperature threshold that could lead to widespread melting.

A team led by Oxford University scientists studied stalactites and stalagmites in caves along Siberia’s permafrost frontier, where the ground begins to be permanently frozen in a layer tens to hundreds of meters thick.

The stalactites and stalagmites only grow when liquid rainwater and snow melt drips into the caves. The formations record 500,000 years of changing permafrost conditions, including warmer climate periods. After studying the paleoclimate clues in the caves, the researchers concluded that another 1.5 degrees of warming would be enough to cause substantial thawing of permafrost far north from its present-day southern limit. (more…)

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