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
Tag Archives: Attribution
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
13 December 2017, World Weather Attribution, Climate Change Fingerprints Confirmed in Hurricane Harvey’s Record-Shattering Rainfall. Scientist with World Weather Attribution (WWA) find that human-caused climate change made the record rainfall that fell over Houston during Hurricane Harvey roughly three times more likely and 15 percent more intense. WWA is releasing the findings of its new analysis regarding the role of human-induced climate change on Hurricane Harvey’s devastating rains that is published in the peer-reviewed journal, Environmental Research Letters (ERL). The findings are being released jointly with the American Geophysical Union (AGU) in a joint press release and at a press conference on Wednesday, December 13 at 2:30 p.m. CT at the annual AGU Fall Meeting in New Orleans. The paper can be found on our website and in Environmental Research Letters.
13 December 2017, American Meteorological Society, Explaining Extreme Events from a Climate Perspective. This Bulletin of the American Meteorological Society (BAMS) special report presents assessments of how human-caused climate change may have affected the strength and likelihood of individual extreme events. This sixth edition of explaining extreme events of the previous year (2016) from a climate perspective is the first of these reports to find that some extreme events were not possible in a preindustrial climate. The events were the 2016 record global heat, the heat across Asia, as well as a marine heat wave off the coast of Alaska. While these results are novel, they were not unexpected. Climate attribution scientists have been predicting that eventually the influence of human-caused climate change would become sufficiently strong as to push events beyond the bounds of natural variability alone. It was also predicted that we would first observe this phenomenon for heat events where the climate change influence is most pronounced. Additional retrospective analysis will reveal if, in fact, these are the first events of their kind or were simply some of the first to be discovered. Read More here
Related links
- Scientists Can Now Blame Individual Natural Disasters on Climate Change
- State of the Climate in 216: Special Supplement to the Bulletin of the American Meteorological Society Vol. 98, No. 8, August 2017
- Pruitt’s Plan to Debate Climate Science Paused as Science Confirms Human Link to Extreme Weather
- Munich RE: Rapid attribution: Is climate change involved in an extreme weather event? and access full report – Natural catastrophes 2016 Analyses, assessments, positions 2017 issue – at bottom of page “Further Information”
- Three 2016 extremes ‘not … possible’ without human warming
- Global Warming Index update and A real-time Global Warming Index report and New index of warming due to human influence on climate released