'Not a Mistake': NASA in Disbelief over Rate of Melting Ice

'Not a Mistake': NASA in Disbelief over Rate of Melting Ice

Greenland ice sheet melted at unprecedented rate during July

- Common Dreams staff

The Greenland ice sheet on July 8, left, and four days later on the right. An estimated 97% of the ice sheet surface had thawed by July 12.

Scientists say there has been a freak event in Greenland this month: Nearly every part of the massive ice sheet that blankets the island suddenly started melting.

The ice melted so fast that scientists at NASA first thought it was a computer error or some other malfunction.

For several days this month, Greenland's surface ice cover melted over a larger area than at any time in more than 30 years of satellite observations, according to a statement released along with satellite images on Tuesday.

"This was so extraordinary that at first I questioned the result: was this real or was it due to a data error?" Son Nghiem of NASA's jet propulsion laboratory in Pasadena said in the release.
But after conferring with colleagues, Nghiem's disbelief turned to shock.

"I think it's fair to say that this is unprecedented," Jay Zwally, a glaciologist at NASA's Goddard Space Flight Center, told The Guardian.

On average in the summer, about half of the surface of Greenland's ice sheet naturally melts. At high elevations, most of that melt water quickly refreezes in place. Near the coast, some of the melt water is retained by the ice sheet and the rest is lost to the ocean. But this year the extent of ice melting at or near the surface jumped dramatically. According to satellite data, an estimated 97 percent of the ice sheet surface thawed at some point in mid-July.

Researchers have not yet determined whether this extensive melt event will affect the overall volume of ice loss this summer and contribute to sea level rise.

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US Wildfire Map Reveals Rising Menace

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U.S. Wildfires Map Reveals Rising Menace

Posted: 07/22/2012 1:57 am Updated: 07/22/2012 2:03 am

By Andrea Mustain, OurAmazingPlanet Staff Writer:

A new map, done up in blazing color, plots more than a decade's worth of the massive fires that have hit the United States, offering a revealing portrait of an increasingly common menace.

On a stark black background, complete with topographic features, the map shows not only where fires have burned between 2001 and July 2012, but also shows their intensity, veering from a wash of purplish dots for the smallest fires, up through stipples of red and smears of searing yellow for the mightiest blazes.

The data, provided by two NASA satellites, were "about two mouse clicks away," said John Nelson, the map's maker, and the user experience and mapping manager for IDV Solutions, a Lansing, Mich., data-visualization company.

Nelson, whose recent world earthquake map proved a fascinating undertaking, said the devastating images of Colorado Springs's recent destructive wildfires got him wondering about the history and reach of dangerous blazes, and he easily tracked down some relevant information on U.S. government agency websites.
 
Numbers as pictures

For the purposes of his map, Nelson plotted only fires of at least 100 megawatts (MW), and those for which NASA expressed at least a 50 percent confidence rating. "I wanted to capture the more meaningful fire events," he said.

Since it's hard to visualize what a megawatt actually means— "I was asking myself, 'What the deuce is a megawatt?'" Nelson said — he looked through Wikipedia for a device to express the measure in a more concrete way, and settled on the average summertime capacity of a nuclear power plant, or about 1,000 megawatts.

A search through 2010 numbers from the U.S. Energy Information Administration suggests that number — about 1,000 megawatts — is a fairly accurate representation of average plant capacity over the course of a year.

Although some of the burns captured on the map could be so-called prescribed burns — controlled blazes that officials set to clear out flammable tinder from fire-prone areas —all but the tiniest fires are almost undoubtedly wildfires, and a time-scale version of the map shows the number of fires growing over the decade, a reflection of an alarming trend that fire researchers know all too well.
 
Fiery uptick

"Fire activity has definitely increased in terms of overall activity and acreage burned, and that's not just in the United States," said William Sommers, a research professor at George Mason University's EastFIRE Laboratory, and a former longtime director of fire research for the U.S. Forest Service.
Sommers said that prescribed burns aren't likely to have increased very much in recent decades because of strict regulation at the state level — pollution laws limit the number of burns allowed. In addition, he said, the preventative burns are not nearly as powerful as wildfires, and NASA instruments simply can't see them as well.

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Climate Change and Extreme Weather Linked

Climate Change, Extreme Weather Linked In Studies Examining Texas Drought And U.K. Heat

* 2011 was among 15 warmest years globally - U.S. agency

* Extreme weather events show influence of climate change

* Greenhouse gas levels in atmosphere reaches new high

By Deborah Zabarenko

WASHINGTON, July 10 (Reuters) - Climate change increased the odds for the kind of extreme weather that prevailed in 2011, a year that saw severe drought in Texas, unusual heat in England and was one of the 15 warmest years on record, scientists reported on Tuesday.

Overall, 2011 was a year of extreme events - from historic droughts in East Africa, northern Mexico and the southern United States to an above-average cyclone season in the North Atlantic and the end of Australia's wettest two-year period ever, scientists from the U.S. National Oceanic and Atmospheric Administration and the United Kingdom's Met Office said.

In the 22nd annual "State of the Climate" report, experts also found the Arctic was warming about twice as fast as the rest of the planet, on average, with Arctic sea ice shrinking to its second-smallest recorded size.

Heat-trapping greenhouse gas concentrations - carbon dioxide, methane and nitrous oxide among others - continued to rise last year, and the global average atmospheric concentration for carbon dioxide went over 390 parts per million for the first time, an increase of 2.1 ppm in 2010.

"Every weather event that happens now takes place in the context of a changing global environment," Deputy NOAA Administrator Kathryn Sullivan said in a statement. "This annual report provides scientists and citizens alike with an analysis of what has happened so we can all prepare for what is to come."


Beyond measuring what happened in 2011, the international team of scientists aimed to start answering a question weather-watchers have been asking for years: can climate change be shown to be responsible for specific weather events?


RAISING THE ODDS

The climate experts acknowledged that event attribution science, as it is called, is in its early stages.

"Currently, attribution of single extreme events to anthropogenic climate change remains challenging," Peterson, Stott and other scientists wrote in a study published in the Bulletin of the American Meteorological Society.

Attribution is possible, they said, as long as it is framed in terms of probability, rather than certainty. So instead of saying climate change caused a heat wave, researchers could gauge how much more or less likely the heat wave was in a world where the climate is changing.

For example, both Texas and England felt the warming effects of the La Nina weather-making pattern but climate change pushed these influences to extremes, Stott said.

La Nina, a recurring patch of cool water in the equatorial Pacific that alternates with the warm-water phenomenon El Nino, would typically bring heat to Texas, the researchers said in an online briefing.

Adding climate change to La Nina makes a Texas heat wave 20 times more likely than it would have been 50 years ago, said Peter Stott of the Met Office. By some measures, 2011 was the warmest, driest growing season in the Texas record, Stott said.


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The full report is available online at http://www.ncdc.noaa.gov/bams-state-of-the-climate/2011.php .

Highlights are at http://www.climatewatch.noaa.gov/article/2012/state-of-the-climate-in-2011-highlights/2 . (Reporting By Deborah Zabarenko; Editing by Bill Trott)

More extreme events convincing many Americans climate change is real

US science official says more extreme events convincing many Americans climate change is real

By Associated Press, Published: July 5 | Updated: Friday, July 6, 12:27 AM

CANBERRA, Australia — Increasingly common experiences with extreme climate-related events such as the Colorado wildfires, a record warm spring and preseason hurricanes have convinced many Americans climate change is a reality, the head of a U.S. scientific agency said Friday.

Many Americans had previously seen climate change as a “nebulous concept” removed from them in time and geography, said National Oceanic and Atmospheric Administration chief Jane Lubchenco.

“Many people around the world are beginning to appreciate that climate change is under way, that it’s having consequences that are playing out in real time and, in the United States at least, we are seeing more and more examples of extreme weather and extreme climate-related events,” Lubchenco told a university forum in the Australian capital of Canberra.

“People’s perceptions in the United States at least are in many cases beginning to change as they experience something first-hand that they at least think is directly attributable to climate change,” she said.

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