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