29 December 2017, The Conversation, 2017: the year in extreme weather. Overall 2017 will be the warmest non-El Niño year on record globally, and over the past 12 months we have seen plenty of extreme weather, both here in Australia and across the world. Here I’ll round up some of this year’s wild weather, and look forward to 2018 to see what’s around the corner. Drought and flooding rains… again It feels as if Australia has had all manner of extreme weather events in 2017. We had severe heat at both the start and end of the year. Casting our minds back to last summer, both Sydney and Brisbane experienced their hottest summers on record, while parts of inland New South Wales and Queensland endured extended periods of very high temperatures. More recently Australia had an unusually dry June and its warmest winter daytime temperatures on record. The record winter warmth was made substantially more likely by human-caused climate change. The end of the year brought more than its fair share of extreme weather, especially in the southeast. Tasmania had by far its warmest November on record, beating the previous statewide record by more than half a degree. Melbourne had a topsy-turvy November with temperatures not hitting the 20℃ mark until the 9th, but a record 12 days above 30℃ after that. November was rounded off by warnings for very severe weather that was forecast to strike Victoria. Melbourne missed the worst of the rains, although it still had a very wet weekend on December 2-3. Meanwhile, northern parts of the state were deluged, with many places recording two or three times the December average rainfall in just a couple of days. Read More here
Category Archives: Impacts Observed & Projected
19 December 2017, DeSmog, Pruitt’s Plan to Debate Climate Science Paused as Science Confirms Human Link to Extreme Weather. The same week that a slew of new scientific reports confirmed just how much humans are changing the climate, and in turn, the rest of the planet, Environmental Protection Agency Chief Scott Pruitt’s plans for a “Red Team, Blue Team” debate of this very same science were put on hold. The military-style exercise that would falsely pit the overwhelming majority of climate scientists against a handful of non-experts is an eight-year-old talking point of the notorious climate-denying think tank the Heartland Institute (which is likely not surprised by this development). Meanwhile, last week in New Orleans, several groups of prominent climate scientists shared their latest findings at the world’s largest gathering of Earth and planetary scientists. The roughly 25,000 attendees of the American Geophysical Union annual meeting included scientific leaders from academia, government, and the private sector. Clear and Present Climate Science These peer-reviewed reports make it clear that any meaningful climate debate in the future should not be over the degree of humanity’s role in climate change, but to what degree the climate has changed already and what can be done to stop it. The American Meteorological Society’s 2016 “State of the Climate” report offers the first examples of extreme weather events not possible in a preindustrial climate. “Climate change was a necessary condition for some of these events in 2016, in order for them to happen,” Jeff Rosenfeld, editor in chief of the Bulletin of the American Metrological Society, said at a press conference. “These are new weather extremes made possible by a new climate. They were impossible in the old climate.” Read more here
18 December 2017, Inman, The coastal mortgage time bomb. Experts worry that if insurers start to pull out of flood-prone seaside communities, it could cause a crisis worse than 2008. 2017 will be remembered as the year the water came. Hurricane Harvey dropped as much as 60 inches of rain on parts of Houston, shattering American meteorological records. Hurricane Irma was the strongest tropical storm ever recorded outside the Gulf of Mexico and the Caribbean Sea, and plowed through Florida in early September, turning Miami’s main drag into a raging river. And Category 4 Hurricane Maria pulverized Puerto Rico with 150-mph winds, leaving the island in darkness and ruin. Altogether, the three storms will cost the U.S. more than $200 billion, which would make 2017 the most expensive hurricane season on record.Yet there is every reason to expect that the towns and the cities hit by the hurricanes of 2017 will be rebuilt — even, eventually, devastated Puerto Rico. Thank the federal government — when a storm or flood strikes a community, Washington is there with generous disaster relief, either through billions of dollars in direct aid or through the cushion of federally-subsidized flood insurance plans. The confidence in the federal government’s backing keeps lenders sending money to disaster-hit communities, which encourages residents to stay put and rebuild, rather than flee for safer areas. This in turn ensures that tax money keeps flowing to local governments. That’s why New Orleans, more than 10 years after suffering through one of the worst hurricanes on record, now has a tax base twice as large as it did before Katrina, and why the South Florida city of Homestead is nearly three times as populous as it was before Hurricane Andrew flattened it in 1992. Read More here
14 December 2017, The Conversation, Not just heat: even our spring frosts can bear the fingerprint of climate change. In recent years, scientists have successfully identified the human fingerprint on hot years, heatwaves, and a range of other temperature extremes around the world. But as everyone knows, climate change affects more than just temperature. The “signal” of human-induced climate change is not always clear in other weather events, such as cold snaps or episodes of extreme rainfall. Three new studies, released today as part of a special edition of the Bulletin of the American Meteorological Society, take a closer look at two such events, both of which happened in southern Australia in mid-2016: the frosts that hit Western Australia’s South West, and the extremely wet weather that hit much of southeastern Australia during that year’s winter and early spring. Perhaps surprisingly, WA’s frosts showed a fingerprint of climate change, due to changes in weather patterns. Meanwhile, there was very little climate change signal in the extreme rainfall that hit the southeast. While there is a clear human-driven upward trend in Australia’s average temperatures and the future of southern Australia is projected to be dry in the cool seasons, last year Australia experienced its wettest winter and September on record. Meanwhile, September in WA’s South West brought up to 18 frost nights across the region – the most on record in some locations. An increasing temperature trend would limit the number of extreme cold events, and broadly speaking this is true for Australia. So what caused the record frost risk in South West WA in September 2016? For the northern hemisphere, a “wobbly” jet stream has been proposed as the cause of periodic blasts of extreme cold weather. In this theory, human-driven changes to atmospheric circulation cause Arctic air to temporarily extend southwards over populated areas, bringing Arctic weather in spite of the background warming trend. But this kind of theory hasn’t been examined in depth for Australia. Read More here