Posted tagged ‘climate change’

The “Great Green Wall” of Africa

June 23, 2010

A group of African nations are meeting to discuss plans to plant a continuous line of trees across the continent.  The “Great Green Wall” involves constructing a tree belt 9 miles (15 kilometers) wide and 4,831 miles (7,775 kilometers) long across the southern edge of the Sahara which includes 11 African countries from Senegal in the west to Djibouti, Ethiopia and the Indian Ocean in the east. 

Scientists hope the “Great Green Wall” will stop the encroaching desert, slow soil erosion, help slow wind speeds and help rainwater filter into the ground.

Methane Under Arctic Seabed Destabilizing

March 8, 2010
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Huge quantities of methane previously frozen under the Arctic seabed is being released at a much higher rate than scientists previously thought.  Researchers made thousands of observations of the Eastern Siberian Arctic Shelf on the north coast of Russia and determined that 8 million tons of methane were being released per year from that area.  This amount is equivalent to the total amount scientists had estimated for all the world’s oceans.  While it is unclear if this a new source of methane, researchers did point out that methane in the atmosphere above the Arctic is higher than at any time in the last 400,000 years.

Snowflakes Help Answer Questions About Ozone

December 11, 2009
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Scientists have been studying the chemistry of snowflakes in order to understand ozone depletion better.  Ice, with its thin layer of liquid, has a significant number of complex chemical reactions occur in this layer.  These reactions cause the release of chemicals that reduce ground-level ozone.  Flakes with more branches have larger surface areas which allows more reactions to occur.  While the implications of this are not completely known, scientists are focused on discovering the role of ice & snow play in climate change.

Antarctic Experiencing Ice Loss Faster Than Previously Thought

November 27, 2009
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According to a new study by scientists at the University of Texas, the East Antarctic ice sheet, once thought to be unaffected by global warming, is melting fast.  Estimates using satellite observations place ice loss in the East Antarctic at 5 to 109 gigatons per year from April 2002 to January 2009.  But, estimates also suggest that the rate of melt sped up after 2006.  This loss is seen most in coastal regions such as Wilkes Land and Victoria Land.  Previous estimates of the East Antarctic ice sheets ranged between a 4 gigaton per year loss and a 22 gigaton per year gain.

California Sets Energy Standards For TVs

November 20, 2009
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In an effort to reduce greenhouse gas emissions California has set tough new energy efficiency standards for televisions under 58 inches.  The new rules mandate that, starting in 2011, televisions sold in California consume 33% less electricity than current models.  Efficiency standards toughen even further in 2013 with a 49% reduction in electricity usage mandated.  These new standards are motivated by the fact that flat-screen TVs use, on average, 40% more energy than the old-style cathode ray tube TV sets they replaced.  Typically, TVs account for 10% of home energy use, so a these regulations have the potential for significant savings for a typical household.

Are Biofuels Really Green?

November 5, 2009
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Two studies recently published in the journal Science claim that biofuels, as they are currently created and used, are not as green as the public believes.  One study projects the impacts of a ramp-up of biofuel production over this century.  As biofuel production increases, both cropland currently used for food and pastureland would potentially be put into biofuel production.  This could drastically impact global food supplies.  There would also be an increase in carbon emissions due to the amount of fertilizer needed to grow crops for biofuel.  Increased fertilizer use would in turn increase emissions of nitrous oxide, a potent greenhouse gas.

The second study found a flaw in the method used to calculate carbon emissions from bioenergy.  Currently, government calculations treat biofuels as if they are carbon neutral, which they clearly are not.  When biofuels are burned they do release CO2 into the atmosphere.  Also, if biofuel production decreases plant growth, which would decrease the removal of CO2 from the atmosphere, CO2 levels would increase.  For more information on these studies, see Reuters.

Snows on Mount Kilimanjaro Likely Gone in 20 Years

November 3, 2009
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Made famous by Ernest Hemingway, who wrote the short story “The Snows of Kilimanjaro”, Mount Kilimanjaro is in danger of losing its famous snowy peak.  Research published this week in the Proceedings of the National Academy of Sciences suggests that all the glaciers on Mount Kilimanjaro may completely disappear in the next twenty years.  In 2007, 85% of the glaciers present in 1912 had melted.  Additionally, 25% of the glaciers present in 2000 had melted by 2007.  While changes in snowfall and cloudiness have an impact on the melting, the researchers pointed to increased global temperatures as the main culprit.  For more information, see Science Daily.