28 August 2017, Climate Home, Link between Hurricane Harvey and climate change is unclear. Reports the devastating storm was made worse by humanity’s carbon emissions fail to grasp climate change is not just about warming. The unprecedented amount of rainfall accompanying Hurricane Harvey immediately raised the question whether and to what extent climate change is to blame. In a warming world the vapour capacity of the atmosphere increases, and more extreme rainfall, like Texas is witnessing right now, is to be expected as a result. This leads many to conclude that climate change exacerbated the impacts of hurricane Harvey. It is very appropriate to highlight that this is the kind of event we expect to see more of in a warming world. However, to apply this argument directly and attribute (and quantify) the impacts from Harvey itself to human-induced climate change, neglects that climate change is not just about warming. In a changing climate, two effects come together: not only does the atmosphere warm up (thermodynamic effect) but the atmospheric circulation, which determine where, when, and how weather systems develop, can change as well (dynamic effect). Read More here
Tag Archives: Extreme Events
28 August 2017, Desmog, 12 Years After Katrina, Hurricane Harvey Pummels Gulf Coast and Its Climate Science-Denying Politicians. As the remnants of Hurricane Harvey (now a tropical storm) continue to flood Houston — just days before the 12th anniversary of Hurricane Katrina — I visited Shannon Rainey, whose house was built on top of a Superfund site in the Upper Ninth Ward of New Orleans. Rainey is worried about family members in Houston. She knows all too well how long it can take to get back what is lost in a storm. “I still live with Katrina every day,” she told me. New Orleans remains threatened by bands of rain extending from Harvey, causing many residents with fierce memories of Katrina to remain on edge. Earlier this month, the city proved it was ill-prepared for hurricane season nearly a year after Baton Rouge’s 1,000-year flood. Rain inundated New Orleans, with more than nine inches falling in only three hours, exposing that the city’s pump system could not operate at full capacity. The city is still scrambling to make the needed repairs and clean the sewer system’s catch basins, which remain clogged in many places. Read More here
28 August 2017, Climate Home, Link between Hurricane Harvey and climate change is unclear. Reports the devastating storm was made worse by humanity’s carbon emissions fail to grasp climate change is not just about warming. The unprecedented amount of rainfall accompanying Hurricane Harvey immediately raised the question whether and to what extent climate change is to blame. In a warming world the vapour capacity of the atmosphere increases, and more extreme rainfall, like Texas is witnessing right now, is to be expected as a result. This leads many to conclude that climate change exacerbated the impacts of hurricane Harvey. It is very appropriate to highlight that this is the kind of event we expect to see more of in a warming world. However, to apply this argument directly and attribute (and quantify) the impacts from Harvey itself to human-induced climate change, neglects that climate change is not just about warming. In a changing climate, two effects come together: not only does the atmosphere warm up (thermodynamic effect) but the atmospheric circulation, which determine where, when, and how weather systems develop, can change as well (dynamic effect). Changes in the atmospheric circulation can increase the thermodynamic effect (as we saw during floods Louisiana in 2016) or act in the opposite direction to the thermodynamic effect, leading to locally decreasing the risk of extreme rainfall or canceling the effect of the warming alone (examples here). Dynamical factors and thermodynamic aspects of climate change can interact in complex ways and there are many examples where the circulation is as important as the thermodynamics. Read More here
21 August 2017, The Conversation, Dry winter primes Sydney Basin for early start of bushfire season. It might feel like the depths of winter, but Australian fire services are preparing for an early start to the bushfire season. Sydney has been covered with smoke from hazard reduction burns, and the New South Wales Rural Fire Service has forecast a “horrific” season. Predicting the severity of a bushfire season isn’t easy, and – much like the near-annual announcements of the “worst flu season on record” – repeated warnings can diminish their urgency. However, new modelling that combines Bureau of Meteorology data with NASA satellite imaging has found that record-setting July warmth and low rainfall have created conditions very similar to 2013, when highly destructive bushfires burned across NSW and Victoria. Crucially, this research has found we’re approaching a crucial dryness threshold, past which fires are historically far more dangerous.How to measure bushfire fuel On September 10, 2013 several bushfires in Sydney’s West caused havoc well before the official start of the bushfire season. These were a precursor to fires that destroyed more than 200 properties a month later. Warm, dry winter weather had dried out the fuels in Sydney’s forests and bush reserves beyond “normal” levels for the time of year. The timing and severity of those preseason fires were a reminder that the region’s forests are flammable all year round; they can burn whenever the fuel they contain dries out past a certain threshold. Read More here