Paradise by the Northern Lights The warming of the world is settled fact. That we humans and our act

Paradise by the Northern LightsThe warming of the world is settled fact. That we humans and our activities are largely the primary driving force behind that ongoing warming is not seriously disputed by scientists. But what’s a few degrees between friends?The reality is, not all of the world will experience the same level of warming. In fact, parts of the world are already warming a great deal more than the rest. One of those rapidly warming parts is that part of the Northern Hemisphere known as the Arctic.As the area of the world closest to the North Pole, the Arctic has historically been extremely cold in winter and considered by most humans to be barely livable at the height of its brief summers. But that is changing. A study just released shows that over the past 3 decades, the Arctic has experienced greater warming than the rest of the planet, and that the portion of the year spent above freezing has grown longer and hotter. As a result, the growing season has become longer and more hospitable to plant growth.Interestingly, temperatures and vegetation growth now resemble those found 4-6 degrees of latitude or 400-700 kilometers to the south (250-430 miles).“It’s like Winnipeg, Manitoba, moving to Minneapolis-Saint Paul in only 30 years,” said study co-author Compton Tucker of NASA’s Goddard Space Flight Center in Greenbelt, Md.So why is this not the ideal problem some might think it to be? As the vegetation cover increases, the albedo of the Earth (the “whiteness” of the Earth) darkens, which means that the Earth will retain even more energy from the Sun than it has in the past. This in turn will further warm the Earth.“This sets in motion a cycle of positive reinforcement between warming and loss of sea ice and snow cover, which we call the amplified greenhouse effect,” said the study co-author Ranga Myneni said. “The greenhouse effect could be further amplified in the future as soils in the north thaw, releasing potentially significant amounts of carbon dioxide and methane.”As the Earth warms, the Arctic will warm further still. As the Arctic warms, much of the permanently-frozen ground (known as permafrost or yedoma) will thaw, releasing vast quantities of stored carbon in the form of greenhouse gases such as methane and carbon dioxide. And the summer sea ice covering the Arctic Ocean will continue to dwindle, eventually disappearing altogether (the subject of my next post).By the end of this century, the increases in temperatures and vegetation growth now resemble those found 20 degrees of latitude or 2,000-3,500 kilometers to the south (1,250-2,150 miles).The last time that the Earth experienced the level of atmospheric carbon dioxide we now see was 3.5 million years ago, when temperatures in the Arctic were some 11-16°C (19-28°F) and global sea levels were some 23 meters (70 feet) above those of today. Given the ongoing increase in atmospheric CO2 from our human activities, that is the world we are returning our climate to.-DBImage Credit: NASA’s Goddard Space Flight Center Scientific Visualization StudioStory Source:Amplified Greenhouse Effect Shaping North Into Southhttp://www.nasa.gov/topics/earth/features/growth-shift.htmlhttp://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1836.htmlResources:Ancient Fossils Hold Clues for Predicting Future Climate Changehttp://xa.yimg.com/kq/groups/18383638/756302608/name/sdarticle.pdfhttp://www.sciencedirect.com/science/article/pii/S0012821X11001099Thawing Permafrost Likely Will Accelerate Global Warminghttp://www.tellusb.net/index.php/tellusb/article/view/16197Caves Point to Thawing of Siberia: Thaw in Siberia’s Permafrost May Accelerate Global Warminghttp://www.sciencemag.org/content/early/2013/02/20/science.1228729.abstractNot-So-Permanent Permafrost: 850 Billion Tons of Carbon Stored in Frozen Arctic Ground Could Be Releasedhttp://onlinelibrary.wiley.com/doi/10.1029/2012GL051958/abstract;jsessionid=CE309CAE91402E485689AAA6F160A093.d02t03Abrupt Permafrost Thaw Increases Climate Threathttp://www.nature.com/nature/journal/v480/n7375/full/480032a.htmlSunlight Stimulates Release of Climate-Warming Gas from Melting Arctic Permafrosthttp://www.pnas.org/content/110/9/3429Carbon Release from Collapsing Coastal Permafrost in Arctic Siberiahttp://www.nature.com/nature/journal/v489/n7414/full/nature11392.html -- source link

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