PLEA Network

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