For sea ice, age matters

Most people picture the Arctic Ocean as miles upon miles of thick sea ice. This icy expanse has become threatened as Arctic sea ice shifts from mainly old ice to much younger, thinner ice. How does this shift impact the Arctic environment? And what is the connection between the average age of ice found in the Arctic and the overall sea ice decline? Continue reading

Core of climate history

Lou and the Ice Core Drill

Scientists take ice core samples in cold, windy, and forbidding environments. After drilling through solid ice to retrieve a core, initial measurements are taken before it is sent away for more in-depth analysis and storage. Photo credit: NSIDC courtesy Ted Scambos and Rob Bauer

People have asked how scientists know that today’s climate situation is unusual. Hasn’t the Earth undergone many cold and warm cycles before? Could this just be another? Buried in the world’s ice sheets is a long story of climate on Earth–and the contribution of atmospheric CO2 to warming or cooling. Scientists can access a unique and detailed look at the history of the Earth’s atmosphere through ice cores and start to understand the recent climate in context of past ones. Continue reading

The ebb and flow of glacial lakes

800px-Quelccaya_Glacier

The Quelccaya Glacier in Peru is the largest glacier in the tropics. This glacier provides water to the city of Lima and contributes to hydroelectric power. In the last fifteen years, it has retreated nearly 195 feet per year. The increasing presence of glacial lakes around it reflects its unprecedented recession. Photo credit: Edu Bucher (http://en.wikipedia.org/wiki/File:Quelccaya_Glacier.jpg)

People sometimes ask us what it means if the world’s glaciers melt because of warmer temperatures. As Earth’s climate warms, the fate of the world’s shrinking glaciers matters to people who depend on them for meltwater. An increase in glacial lakes may mean more water for the present but leaves many to wonder how reliable this source of water will be if glaciers continue to recede. But what are glacial lakes and how do they form? Are they a part of a normal, healthy glacier, or evidence of glacier decline? Continue reading

A thawing, rotting Arctic?

Permafrost thaw causes the ground to become unstable as the soil collapses. This can damage building and roads built on permafrost. Cracks also expose the carbon stored within to sunlight, which may speed the release of carbon dioxide, a greenhouse gas. Photo credit: Dentren (http://upload.wikimedia.org/wikipedia/commons/a/ac/Storflaket.JPG)

Permafrost thaw causes the ground to become unstable as the soil collapses. This can damage building and roads built on permafrost. Cracks also expose the carbon stored within to sunlight, which may speed the release of carbon dioxide, a greenhouse gas.
Photo credit: Dentren (http://upload.wikimedia.org/wikipedia/commons/a/ac/Storflaket.JPG)

As greenhouse gas emissions continue to rise, researchers are looking at a source of even more carbon emissions: thawing permafrost. A warming Arctic may cause significant amounts of dead, organic material currently frozen in permafrost to thaw out and decay, releasing more carbon into the atmosphere. How exactly does permafrost store carbon? And what are the consequences if the permafrost thaws?

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