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
Guest post by Walt Meier, NSIDC Scientist
Arctic sea ice set a record minimum extent in September 2012, far below the previous record low in 2007. Summer extents have been far lower than average for the last decade, with several record or near-record years. Looking at the numbers, one is tempted to think that the Arctic Ocean may reach nearly sea ice-free conditions within just a few years. But most expert analyses indicate that we’re likely at least a couple decades away from seeing a blue Arctic Ocean during the summer.
NSIDC recently switched the baseline against which we analyze Arctic sea ice extent. Previously, we relied on a baseline that coincided with the beginning of the satellite period and stretched 20 years, from 1979 to 2000. The new baseline runs from 1981 to 2010, covering 30 years. Why did we make such a change?
Switching to a 30-year baseline allows us to be consistent with other climate monitoring agencies, which commonly use a 30-year time period for conducting analyses. This new baseline also helps account for the wider variations observed in Arctic sea ice extent. Continue reading
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?
If gardening in icy Greenland sounds unbelievable, think again. A chef in Kangerlussuaq has started growing tomatoes, peppers, herbs, and even strawberries for his restaurant, and Greenland’s potato production doubled between 2008 and 2012. These agricultural feats would have been impossible only a hundred years ago. The Arctic has been warming over the past several decades at a rate twice as fast as the rest of the globe. As the region warms, several teams of scientists have been tracking changes in Arctic vegetation, trying to see if higher temperatures mean more green. Continue reading