Greg Harman
Al Gore's decision to hang An Inconvenient Truth on the fear-inducing hurricane whorl hasn't served the prophets of climate change very well.
While researchers across the planet have reached deep consensus on issues of planetary warming, desertification, rising seas, and melting ice, the question of how hurricanes will respond to global warming is still being vigorously debated.
While the case for stronger, â??warming'-fortified hurricanes is strong, it is less clear whether rising global temps will increase the number of storms on tap for coming years.
It may not matter much.
We've already entered a natural cycle of increased storm activity that could last into the 2020s â?? a change driven by the heat transferred by the Atlantic Ocean known as the Atlantic Multidecadal Oscillation, or AMO.
Last week, researchers at Texas A&M University released a study suggesting that minor increases in sea levels already underway and damages to protective barrier islands will exacerbate coastal flooding and intensify the impact of hurricanes on coastal development.
The cumulative impact of our warmer Gulf of Mexico, barrier island damage, and storm activity could more than double flooding levels in Corpus Christi by 2080, the report found.
The findings jibe perfectly with those of Asbury Sallenger, leader of the U.S. Geological Survey's National Assessment of Coastal Change Hazards, a program that studies storm and long-term coastal change hazards throughout the United States.
In former blog posts and stories, I've sought to demonstrate sea-level rise projections with a computer model generated by the University of Arizona that takes existing coastal elevations and draws new coastlines depending on the degree of sea-level selected.
Mea culpa.
It's going to be worse than all that.
Predicting the full impact of rising seas on our coastlines is more dynamic than the process of filling a bathtub, after all. You have to factor in the impact of these storms on barrier islands, for one.
Speaking to a gathering of environmental journalists attending the Scripps Howard Institute on the Environment last week, Sallenger, author the just-released book “Island in a Storm,” said the dramatic coastal subsidence across Louisiana made the area a perfect model for forecasting what other coastal areas will see in coming decades as the sea level rises.
What's sinking land but another way of seeing rising seas, after all? And parts of Louisiana are dropping seven times as fast as other parts of the country.
Hurricanes riding to shore on taller seas means that barrier islands â?? like the Chandeleur Islands offsore of Louisiana â?? will be inundated and disassembled by repeated storm surges.
The blast of Hurricane Katrina took a full 85 percent of the Chandeleur's land mass (below).
While, technically, the Chandeleur could rebuild themselves â?? and have already begun to do so â?? at their diminished elevation even the mildest Category One storm would totally submerge the islands.
Second only to Florida, Texas has 350 miles of barrier-island beaches along its coast.
The A&M report released last week considered increases of sea level rise from land subsidence (as is currently affecting the Chandeleur) and the current and future impact of melting glaciers and increased global temperatures.
Here's how Reuter's reported the story:
Corpus Christi, on the south Texas coast, already faces the risk of widespread flooding from the most powerful hurricanes, according to the study.
"Flooding and damage from major hurricanes will be more severe," said study author Jennifer Irish, assistant professor of coastal and ocean engineering at Texas A&M University, in a statement. "And the worse global warming gets, the more severe the consequences for the Texas coast."
Now that the A&M report has generated a few headlines, it will be instructive to see what policy makers do with it.
The report's conclusion reads:
The insurance companies are taking notice. Are your legislators?
Need a greater helping of woe? You can listen to Sallenger's full presentation to the awesomest collection of eco writers on the planet, the Scripps fellows, Class of 2009, over here:
* 'Corruption' here used in reference to the changing landscape of our coasts and is in no way a reference to Dr. Sallenger, expert in the gradual "impairment of integrity" (aka: corruption) of our coastlines.
