29 September 2016, Climate News Network, Speed of Arctic changes defies scientists.The Arctic climate is changing so quickly that science can barely keep track of what is happening and predict the global consequences, the UN says. In an unusually stark warning a leading international scientific body says the Arctic climate is changing so fast that researchers are struggling to keep up. The changes happening there, it says, are affecting the weather worldwide. The World Meteorological Organisation (WMO) says: “Dramatic and unprecedented warming in the Arctic is driving sea level rise, affecting weather patterns around the world and may trigger even more changes in the climate system. “The rate of change is challenging the current scientific capacity to monitor and predict what is becoming a journey into uncharted territory.” The WMO is the United Nations’ main agency responsible for weather, climate and water. Its president, David Grimes, said: “The Arctic is a principal, global driver of the climate system and is undergoing an unprecedented rate of change with consequences far beyond its boundaries. Read More here
Tag Archives: Arctic
7 June 2016, Washington Post, ‘We’ve never seen anything like this’: Arctic sea ice hit a stunning new low in May. The 2016 race downward in Arctic sea ice continued in May with a dramatic new record. The average area of sea ice atop the Arctic Ocean last month was just 12 million square kilometers (4.63 million square miles), according to the National Snow and Ice Data Center (NSIDC). That beats the prior May record (from 2004) by more than half a million square kilometers, and is well over a million square kilometers, or 500,000 square miles, below the average for the month. Another way to put it is this: The Arctic Ocean this May had more than three Californias less sea ice cover than it did during an average May between 1981 and 2010. And it broke the prior record low for May by a region larger than California, although not quite as large as Texas. This matters because 2016 could be marching toward a new record for the lowest amount of ice ever observed on top of the world at the height of melt season — September. The previous record September low was set in 2012. But here’s what the National Snow and Ice Data Center has to say about that: Daily extents in May were also two to four weeks ahead of levels seen in 2012, which had the lowest September extent in the satellite record. The monthly average extent for May 2016 is more than one million square kilometers (386,000 square miles) below that observed in May 2012.In other words, for Arctic sea ice, May 2016 was more like June 2012 — the record-breaking year. Going into the truly warm months of the year, then, the ice is in a uniquely weak state. “We’ve never seen anything like this before,” said Mark Serreze, who directs the center. “It’s way below the previous record, very far below it, and we’re something like almost a month ahead of where we were in 2012.” Granted, the NSIDC called the May numbers “tentative” because of problems with the satellites that scientists rely on to observe the Arctic, but added that they are “supported by other data sources.” Read More here
4 June 2016, Climate News Network, Warming turns northern tundra green. Rising temperatures are creating longer Arctic growing seasons and increasing the risk of carbon escaping into the atmosphere from the thawing permafrost. The northern edge of North America is getting steadily greener. In the most detailed study so far of plant growth across Alaska and Canada, scientists say that about a third of the land cover now looks less like tundra, and more like a warmer ecosystem. The researchers report in the Journal of Remote Sensing that examination of 87,000 images captured by the NASA Landsat satellite reveals that Alaska, Quebec and other regions became greener between 1984 and 2012. Landsat, a project also backed by the US Geological Survey (USGS), provides the longest space-based record of land vegetation in existence. Growing in size “The greening trend was unmistakable,” the scientists report. In Canada, northern forests tended to become greener, although if anything they declined in Alaska. Overall, 29.4% of the region became greener, and only 2.9% declined. The Arctic is the fastest-warming region of the northern hemisphere, with longer growing seasons and thawing permafrost. The scientists saw grassy tundra convert to shrubland, and shrubs grow in size and density, and such changes will inevitably start to play into water, energy and carbon cycles. Read More here
11 April 2016, Springer Link, Significant implications of permafrost thawing for climate change control. Large amounts of carbon are stored as permafrost within the Arctic and sub-Arctic regions. As permafrost thaws due to climate warming, carbon dioxide and methane are released. Recent studies indicate that the pool of carbon susceptible to future thaw is higher than was previously thought and that more carbon could be released by 2100, even under low emission pathways. We use an integrated model of the climate and the economy to study how including these new estimates influence the control of climate change to levels that will likely keep the temperature increase below 2 °C (radiative forcing of 2.6 Wm−2). According to our simulations, the fossil fuel and industrial CO2 emissions need to peak 5–10 years earlier and the carbon budget needs to be reduced by 6–17 % to offset this additional source of warming. The required increase in carbon price implies a 6–21 % higher mitigation cost to society compared to a situation where emissions from permafrost are not considered. Including other positive climate feedbacks, currently not accounted for in integrated assessment models, could further increase these numbers. Read More here