Climate Change and Extreme Weather: Indirect Connections, Probabilities, and Accentuating Factors

Climate Change and Extreme Weather: Indirect Connections, Probabilities, and Accentuating Factors 

After the devastation of 2005 Hurricanes Katrina and Rita and 2008 Hurricane Ike it was predicted by some climate scientists that Atlantic hurricanes were on a trajectory of more hurricanes per year and more powerful hurricanes than before. Over the last 12 years that has clearly not been the case. Even adding in the devastation of Harvey one can conclude that the prediction based on climate modeling and Atlantic weather patterns was not correct. Increasing anthropogenic climate change does make catastrophic storms more probable and throws off predictions based on past events and frequencies alone. 

Basic principles of meteorology show that warmer temperatures lead to higher atmospheric moisture content and thus increased potential for both more frequent and more intense rainfall events. On average this has been confirmed in many places. Recurring weather patterns are also a factor in how much rain falls on a region. Warmer ocean temperatures can enhance the development of tropical storm systems. Warmer temperatures in the Pacific Arctic are thought to have been the main driver of the polar vortices that dipped lower into the continental U.S. for a few winters leading to extended cold and overall colder than average winters. Hurricane Sandy was an unusual storm with multiple features at an unusual time of year. It brought high winds, rain, early snow in some places, and intense storm surge. The so-called “derecho” that wreaked havoc across the U.S. Midwest and Northeast a few summers earlier was also unusual by weather standards. Sea level rise, roughly a foot in the last century on the Gulf Coast, is a result of climate change, most of it likely natural climate change due to  temperature rise and sea level rise as recovery from the Little Ice Age, but anthropogenic warming no doubt is also a factor.

Climate scientist Charles H. Green notes in the Huff Post article referenced below that warming temps in the Arctic affect the jet streams in such a way as to cause storms like Harvey to meander and stall. In the case of Harvey the stalling resulted in unprecedented rain in a small geographic area. Hurricane Sandy was also made worse by the weather system stalling. Green’s research has shown that increased summer melting of Arctic sea ice affects the North Atlantic Oscillation (NAO) which in turn affects jet streams, typically causing the jet stream to become more wavy, dipping southward and in some instances stalling storm tracks across North America. 

Currently there is also severe flooding in India with parts of Mumbai inundated. 1200 people have perished. This is due to the yearly monsoons. According to climate scientist Michael Mann the climate models predict overall weaker monsoons for the region and perhaps more variation (less predictability) which can lead to insufficient rains in some years. However, the overall weaker monsoons can bring more rain per event due to a warmer atmosphere.

Hurricane Harvey and Opportunism

Fossil fuel detractor and capitalism critic Naomi Klein wrote a book called Shock Doctrine that showed instances of people and businesses capitalizing financially off of natural disasters, what she called “disaster capitalism.” Unfortunately, where there is money to be made there will be shysters and fraudsters. The increase in the volume of individual cases of claims on recovery money leaves little room for the oversight required to prevent fraud. Ideologues can also profit from disasters in the sense that they use individual disasters as proof of their view that fossil fuel use must cease now in order to slow out-of-control climate change. The data only show that climate change is a factor in individual storm events, not that it is a primary cause. It may lead to more intense events but cannot be linked as the direct cause of individual events. Thus it is incorrect to say that climate change caused a hurricane or by itself made it more devastating. There are many other factors as well. To proclaim that it is the main direct cause is thus political, perhaps a form of “disaster anti-capitalism.” The op-ed by macroeconomist Jeffrey Sachs is a clear case. Sachs is a thoughtful economist. I have read one of his books and I am working on another. However, his level of condescension and blame in this piece seems to be sheer ideological opportunism. He seems to think the Texas governor should resign, oil companies and their conservative allies should admit guilt and complicity and pay for much of the recovery, and all be forced to admit that adherence to the alarmist version of climate science is the most correct in order to get Federal aid. This is both shameful and ridiculous and a clear example of ideologically capitalizing on a disaster. Sachs was a strong supporter of Bernie Sanders and is clearly in the same alarmist camp toward climate change as his other supporters like Naomi Klein and Bill McKibben. One thing Sachs is right about is that the unpreparedness of the Texas Gulf Coast and Houston is dangerous for the locals and will be expensive for the rest of us.

The severity of the current flooding of Harvey is partially due to drainage issues: pavement coverage, recent destruction of wetlands (I read that 70% of wetlands around Houston were drained and developed between 1992 and 2010), severe subsidence caused by groundwater pumping, the unprecedented amount of rainfall (likely enhanced by climate change/higher temps), and the unusual weather pattern of Harvey in that it stayed over the same area for a very long time period which caused the unprecedented amount of rainfall. The population of the Houston metro-area has grown by over a million people in the last decade and new refining and petrochemical capacity has been added. Houston is also extremely vulnerable to storm surge were a hurricane to make landfall in just the right spot. Harvey hit to the south so storm surge was not a big issue in the Houston ship channel and other vulnerable waterways. 

It has been known for centuries now that the Texas coast is vulnerable to deadly severe hurricanes and a huge chunk of the U.S. refining and petrochemical capacity is there. The current chemical fires at the peroxide plant and toxic shutdown releases from refineries and petrochem plants show inadequate preparation. Bills were introduced in the Texas legislature under the guise of ‘climate change vulnerability assessment’ and ‘protecting public health from the effects of global warming.’ They did not get far and were abandoned. If they had been packaged as disaster preparedness or extreme weather resilience and not politicized they would likely have been taken more seriously. Regardless of what one thinks about climate change we all can pretty much agree on the merits of robust disaster preparedness. It saves lives, property, and protects the environment. Conversely, being unprepared does the opposite. Adaptation to extreme weather events and adaptation to the effects of climate change are essentially the same thing. How much warming or sea level rise is due to humans is irrelevant in disaster preparedness. The Texas Gulf Coast is apparently, woefully unprepared. The Esquire article referenced below politicizes the unpreparedness as a product of conservative shrinking government, pro-business/pro-development policies, and it is hard to argue that wasn’t a factor. However, the issues there are mainly flood control and adaptation to flooding and that is what the focus should be. Much of the problem is local-level lack of preparedness and increased vulnerability from the drainage issues mentioned above. To be fair the level of local rain from Harvey was quite unprecedented. Even so, it is well known that Houston and vicinity were so vulnerable to hurricanes, storm surges, and flooding that a catastrophic weather event could easily exceed Katrina in recovery cost. We will also pay through increased gasoline costs and other refined product costs like diesel and jet fuel.  

References:

We’re Nowhere Near Prepared for the Ecological Disaster That Harvey is Becoming – by Charles P. Pierce, in Esquire, Aug. 30, 2017

Sachs: Texas Gov. Greg Abbot Needs to Resign – by Jeffrey Sachs, on cnn.com, Aug. 29, 2017

Messenger: When Water Recedes in Houston, Debate over Climate Change and Flooding Must Rise – by Tony Messenger, in St. Louis Post Dispatch, Aug. 28, 2017

Hell and High Water – by Neena Satija and Kiah Collier (Texas Tribune) and Al Shaw and Jeff Larson (ProPublica), March 3, 2016 

Arctic Warming Made Harvey a ‘Killer Storm,’ Climate Researcher Says – by Alexander C. Kaufman, in Huffington Post, Aug. 30, 2017

Storm Warnings: Climate Change and Extreme Weather – from the editors of Scientific American (Dec. 2012)

Michael Mann speaking on Science Friday, Sept. 1, 2017