Tag Archives: northern europe

The Vikings: Yale Historian Looks at the Myths vs. the History

As a lead-up to the forthcoming History Channel series “Vikings,” Tom Ashbrook, host of NPR’s “On Point,” talked with a foremost authority on the subject — Yale’s Anders Winroth — to de-mystify the legendary raiders of the North.

Winroth is  professor and director of graduate studies in history. His most recently published book is “The Conversion of Scandinavia: Vikings, Merchants, and Missionaries in the Remaking of Northern Europe” (Yale University Press, 2011). His forthcoming volume, “A New History of the Viking Age,” will be published by Princeton University Press in 2014. YaleNews spoke with Winroth recently about some of the issues raised in his “On Point” interview. The following is an edited transcript. (more…)

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Nitrogen From Humans Pollutes Remote Lakes For More Than A Century

Nitrogen derived from human activities has polluted lakes throughout the Northern Hemisphere for more than a century and the fingerprint of these changes is evident even in remote lakes located thousands of miles from the nearest city, industrial area or farm.

The findings, published in the journal Science Dec. 16, are based on historical changes in the chemical composition of bottom deposits in 36 lakes using an approach similar to aquatic archeology. More than three quarters of the lakes, ranging from the U.S. Rocky Mountains to northern Europe, showed a distinctive signal of nitrogen released from human activities before the start of the 20th century, said Gordon Holtgrieve, a postdoctoral researcher at University of Washington School of Aquatic and Fishery Sciences and lead author of the report. The UW and a dozen other research institutions contributed to the research. (more…)

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What’s so Unique About the Tropics?

“Less than we thought,” researchers say in a new study providing insights into the distribution of biodiversity across the globe.

The temperate forests of Canada or Northern Europe may have much more in common with the tropical rainforests of Southeast Asia or South America than previously believed, according to a research group including a University of Arizona ecologist.

The assertion, published as the cover article in the journal Science, is focused on the concept of “beta-diversity” – a measure of the change in species composition between two sites, such as neighboring patches of forest. High beta-diversity means that two given sites have few species in common. (more…)

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Earth’s Lakes Warming Due to Climate Change

Lake Tahoe, seen here from Emerald Bay, was one of the primary validation sites for the global lake study. The lake, which straddles the borders of California and Nevada, is the largest alpine lake in North America. Image credit: NASA-JPL

WASHINGTON – In the first comprehensive global survey of temperature trends in major lakes, researchers have determined that Earth’s largest lakes have warmed during the past 25 years in response to climate change. 

Philipp Schneider and Simon Hook of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., used satellite data to measure the surface temperatures of 167 large lakes worldwide. 

They reported an average warming rate of 0.45 degrees Celsius (0.81 degrees Fahrenheit) per decade, with some lakes warming as much as 1 degree Celsius (1.8 degrees Fahrenheit) per decade. The warming trend was global, and the greatest increases were in the mid- to high-latitudes of the Northern Hemisphere.  (more…)

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