16 December 2016, Australian Antarctic Magazine › 2016-2020 › Issue 31, Low winter sea-ice coverage bucks trend. Winter sea-ice coverage around Antarctica was noticeably reduced in September this year, with sea ice extent starting its annual retreat early and setting new daily record lows. The result comes two years after winter sea ice extent around Antarctica reached a record high in September 2014, when it exceeded 20 million square kilometres for the first time since satellite measurements began in 1979. This year, Antarctic sea ice began its annual spring retreat roughly four weeks earlier than average, after peaking at 18.5 million square kilometres on 28 August 2016, which was close to the lowest winter maximum on record. Dr Jan Lieser from the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC) and the Australian Research Council-funded Antarctic Gateway Partnership said it was a surprising finding, given the trend in recent years.“Within the space of just two years we have gone from a record high winter sea-ice extent to record daily lows for this point in the season. This is a great reminder that we are dealing with an extremely variable component of the climate system,” Dr Lieser said. “It’s also a reminder of why it can be unwise to leap to conclusions about the link between Antarctic sea ice and climate change on the basis of one or two years of data. It is the long-term trends that are most important, as well as the regional variability, which is high around Antarctica.” Read More here
Category Archives: Impacts Observed & Projected
16 December 2016, The Conversation, Climate change played a role in Australia’s hottest October and Tasmania’s big dry in 2015. Climate change made some of Australia’s 2015 extreme weather events more likely, according to research published today in the Bulletin of the American Meteorological Society. As part of an annual review of global weather extremes, these studies focused on October 2015, which was the hottest on record for that month across Australia. It was also the hottest by the biggest margin for any month. October 2015 was also the driest for that month on record in Tasmania, which contributed to the state’s dry spring and summer, and its bad fire season. El Niño events usually drive global temperatures higher, and 2015 had one of the strongest on record. So were these records due to El Niño, or climate change? The research shows that while El Niño had some influence on Australia’s weather, it was not the only culprit. El Niño packed a punch – or did it? In 2015, a strong El Niño developed, with record high temperatures in the central equatorial Pacific Ocean contributing to 2015 being the hottest year on record globally (although 2016 will smash it). The Indian Ocean was also very warm. El Niño is often associated with warm and dry conditions across eastern Australia, particularly in spring and summer. The new studies found that for Australia as a whole, while El Niño did make the continent warmer, its direct contribution to record temperatures was small. Only in the Murray Darling Basin did El Niño make it more likely that the October 2015 heat would be a record. El Niño also played a small but notable role in the dry October in Tasmania. Read More here
13 December 2016, Inside Climate News, ‘The Arctic Is Unraveling,’ Scientists Conclude After Latest Sobering Climate Report. The ill winds of climate change are irrevocably reshaping the Arctic, including massive declines in sea ice and snow and a record-late start to sea ice formation this fall. Those were the sobering conclusions of the 2016 Arctic Report Card released Tuesday. The report card is sponsored by the National Oceanic and Atmospheric Administration (NOAA) and co-authored by more than 50 scientists from Asia, North America and Europe. The data shows that the Arctic is warming at double the rate of the global average temperature. Between October 2015 and September 2016, temperatures over Arctic land areas were 2.0 degrees Celsius above the 1981-2010 baseline, the warmest on record going back to 1900. The report, released at the American Geophysical Union meeting in San Francisco, clearly links the Arctic heatwave to a record-late start to formation of sea ice this fall, and to record high and low seasonal snow cover extent in the Northern Hemisphere. If the extreme warmth recorded in the Arctic this fall persists for the next few years, it may signal a completely new climate in the region, scientists said. Jeremy Mathis, director of NOAA’s Arctic Research Program, said the report highlights the clear and pronounced global warming signal in the Arctic and its effects cascading throughout the environment, like the spread of parasitic diseases in Arctic animals. “We’ve seen a year in 2016 like we’ve never seen before … with clear acceleration of many global warming signals. The Arctic was whispering change. Now it’s not whispering. It’s speaking, it’s shouting change, and the changes are large,” said co-author Donald Perovich, who studies Arctic climate at Dartmouth College. Sustained observations of the Arctic is crucial to making science-based policy decisions, he added, a goal threatened by the inclusion of numerous climate deniers in President-elect Donald Trump’s cabinet. This week, Trump’s transition team posted a new “Energy Independence” website that repeats his previous intentions to open up vast areas for fossil fuel development and to scrap existing climate action plans. Arctic ice doesn’t care about politics, and what happens in the region now is critically important to the U.S., said Rafe Pomerance, chair of Arctic 21 and a member of the Polar Research Board of the National Academies of Sciences, Engineering and Medicine. Read More here
12 December 2016, Climate News Network, Methane’s rapid spurt risks climate curbs plan. A recent rapid rise in methane could damage global attempts to slow climate change through cuts in carbon dioxide emissions. One year ago today, with huge relief, scarcely able to believe their achievement, world leaders finally agreed to reduce emissions of carbon dioxide. But a bare 12 months later comes sobering news: atmospheric concentrations of another gas, methane, are growing faster than at any time in the last 20 years, putting further pressure on the historic Paris Agreement to deliver substantial cuts in emissions very soon. Some scientists say the world now needs to change course and do more about methane to have a chance of keeping average global temperatures from rising by more than 2°C. And one seasoned Arctic watcher says the changes there in the last decade are altering a system which has remained intact since the Ice Age. Methane is the second major greenhouse gas, with agriculture accounting for 40% of emissions. Over a century it is 34 times more powerful as a greenhouse gas than carbon dioxide (though far less abundant), but over 20 years methane is 84 times more potent than CO2. In an editorial in the journal Environmental Research Letters, an international team of scientists reports that methane concentrations in the air began to surge around 2007 and grew steeply in 2014 and 2015. In those two years concentrations rose by 10 or more parts per billion annually. In the early 2000s they had been rising by an annual average of 0.5 ppb. Read More here