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15 December 2015, YALE Climate Connections, More Glum News on Arctic Warming.  Arctic’s trailing climate indicators are seen as the leading indicators for climate elsewhere on Earth. News from the Arctic hasn’t gotten any better in the 10 years since NOAA began producing an annual Arctic Report Card, and this year’s collection of results and essays is no exception. NOAA released its latest report December 15 at the meeting of the American Geophysical Union in San Francisco. “The Arctic is warming twice as fast as other parts of the planet,” said Rick Spinrad, NOAA chief scientist, adding “what happens in the Arctic doesn’t stay in the Arctic.” The average Arctic temperature change, 2.3 degrees F (1.3 degrees C) above average, continues to outpace change in the rest of the world, a phenomenon known as “Arctic amplification.” Since the beginning of the 20th century, Arctic warming is now a hefty 5.4 degrees F (3.0 degrees C), leading to significant changes to the region. “One could argue that the trailing indicators in the Arctic are the leading indicators for the rest of the climate,” Spinrad said. Two items from the report, which was written by 72 authors from 11 different countries, were highlighted here: a mysterious browning of Arctic tundra, and the impact of change on walruses. “Greenness” – a measure of photosynthetic activity by satellites — has been declining since 2001 (see Figure below), with a sharp drop-off in the past two to four years, running counter to the notion that more carbon dioxide is unequivocally good for plant life. “We don’t have an answer yet” to the declining greenness, said Howard Epstein, a scientist from the University of Virginia. “A drop in greenness for any given year isn’t alarming, or even two years in a row.” But four years makes for a noticeable trend. Read more here

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9 December 2015, Climate News Network, Ice melt highlights Inuit plight. COP21: As Arctic peoples’ leaders appeal for unity to halt global warming, scientists report that Greenland’s glaciers are now melting at a speed not seen since the last Ice Age. The glaciers of Greenland are retreating two to three times faster now than at any time since the last Ice Age ended 9,500 years ago, according to new research. The news comes as indigenous peoples from the northern polar region staged anArctic Day at the COP21 climate change summit in Paris. Leaders of Greenland peoples, the Nunavut region of Canada and the Inuit Circumpolar Council appealed to the governments of the world to unite to dramatically reduce greenhouse gas emissions and keep global warming to between 1.5˚C and 2˚C. That is because the Arctic is now warming faster than almost anywhere else on Earth, and both human settlements and natural ecosystems are vulnerable. That the Greenland glaciers are in retreat is itself not news. Satellite data and measurements on the ground have repeatedly confirmed the retreat of the glaciers, the loss of ice and the acceleration of flow. The Jakobshavn Isbrae glacier has even reached a speed of 17 kilometres a year. Sediment cores But US scientists report in Climate of the Past journal that the present rate of loss is without precedent. Read More here

 

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14 November 2015, Climate News Network, Greenland glaciers’ melting speeds up again. The increasing rate at which Greenland’s glaciers are melting this century has confounded polar scientists.  A massive Greenland glacier that holds enough water to raise sea levels by half a metre is melting at speed, according to a new study. The Zachariae Isstrom in northeast Greenland has entered a phase of accelerated retreat, and is losing mass at the rate of 5 billion metric tons a year, according to US scientists. They report in the journal Science that a succession of aerial surveys combined with multiple satellite observations has established that the base of the glacier is being eroded rapidly by a mix of warmer ocean water and increasing amounts of meltwater from the surface of the Greenland ice sheet. “North Greenland glaciers are changing rapidly,” said Jeremie Mouginot, an earth system scientist at the University of California, Irvine, who led the study. “The shape and dynamics of the Zachariae Isstrom have changed dramatically over the last few years. The glacier is now breaking up and calving high volumes of icebergs into the ocean, which will result in rising sea levels for decades to come.” Read More here

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22 October 2015, Carbon Brief, Five charts that show how Arctic and Antarctic sea ice is faring in 2015. At this time of year, there are big differences in what’s going on with sea ice at either end of the world. September saw the Arctic hit its fourth lowest summer minimum on record, while over in Antarctica, the winter maximum finished just above average, ending a streak of record highs in the last three years. Carbon Brief takes a look at what’s happened this year and how it fits in with long term trends. Summer minimum Scientists have been using satellites to measure sea ice extent at the north and south poles since the late 1970s. They take measurements daily, and record the annual minimum and maximum as an indicator of how the poles are changing. In the Arctic, the end of the summer marks the point when sea ice is at its smallest extent, before it freezes up again as temperatures fall. Scientists keep a close eye around the time the low is normally reached – usually mid september – then look for signs of ice accumulating again in order to pinpoint exactly when the summer minimum is reached. According to the National Snow and Ice Data Center (NSIDC) in the US, the summer low occurred this year on 11 September. But because sea ice can throw in a late dip or surge, the NSIDC waited until 6 October before finally confirming this summer’s minimum of 4.41m square kilometers (sq km) – the fourth lowest on record. So how did the rest of the season shape up before this point? Read More here

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