La. adapts to natural and manmade climate change

24th October 2011   ·   0 Comments

By Susan Buchanan
Contributing Writer

South Louisiana residents know that the coast is losing a football field of wetlands to the Gulf each hour as well as they know how the Saints played last weekend. Climate change may be controversial but state and local agencies and companies like Entergy Corp. are pursuing plans to adapt to new weather trends. Adaptation could be key to the coast’s future.

Louisiana has lost 16.6 square miles of coastal wetlands yearly since 1985, according to Dr. Virginia Burkett, senior science advisor for climate and land use change at the U.S. Geological Survey. Sea level rise accelerated in the last few decades, destroying Louisiana wetlands, but scientists aren’t sure how much of it was the result of natural variability and how much was human induced, she said.

“The rate of atmospheric warming has accelerated over the past century, especially since 1975,” Burkett said. “We’re seeing a trend towards drier spring and summer in much of the Southeast U.S., from the Carolinas to Southeast Texas, with an increase in temperatures and the propensity for drought. The fall months have grown wetter.” Burkett is based in Many, La.

With rising temperatures and less rainfall, evaporation increases, amplifying chances for drought in the region, she said. Water availability and soil moisture decline. “Atmospheric warming increases sea surface temperatures, which portends more intense hurricanes,” she said.

Burkett continued, saying “Louisiana’s coastal restoration program and 2012 Coastal Master Plan are anticipating increases in sea level. That’s smart because low-lying areas of the Mississippi Delta are considered highly vulnerable to inundation if sea-level rise accelerates as expected.” She said lots of things can be done to reduce flood risks in coastal communities—like increasing the height and stability of levees and restoring wetlands and other land forms. “Many coastal states are developing adaptation plans, though these plans are not required by the federal government,” she said.

Louisiana’s Coastal Protection and Restoration Authority is crafting a 2012 Coastal Master Plan that it says will be used to guide future spending. The agency is considering various measures, including multiple lines of defense through marsh creation and barrier island restoration.

On the corporate side, power producer Entergy Corp., which serves Louisiana, Mississippi, Alabama and Texas, has lost no time addressing climate change. Mic­hael Burns, Entergy spokes­man, said “we’re aggressively advocating for action on climate change at all levels of government and within our communities. Entergy has long believed that the scientific evidence on global climate change was more than sufficient to act to curb greenhouse gases,” which trap heat in the atmosphere.

According to the National Aeronautics and Space Administration, most scientists agree that the main cause of global warming is human expansion of the “greenhouse effect”—by which the atmosphere traps heat that’s radiating from earth toward space.

In 2001, Entergy Corp. was the first U.S. utility to voluntarily commit to stabilizing greenhouse gas emissions, Burns said. Over the last decade, Entergy cut the company’s emissions of carbon dioxide by 69 million tons. Burns said that was done because “as a company serving the Gulf Coast, billions of dollars of investment, and our customer base, the welfare of our employees, their families and our communities are in peril.” Entergy delivers electricity to 2.7 million customers in four states, has annual revenues of over $10 billion and more than 15,000 employees.

A year ago, Entergy released a $4.2 million study, “Building a Resilient Energy Gulf Coast,” in collaboration with America’s Wetlands Foundation, projecting that the region’s economic losses could mount by 2030 because of rising sea levels, land subsidence and vulnerable economic assets. The study recommended adaptation measures—from beach nourishment to retrofitting roofs—to reduce expected losses. According to the analysis, investments of $50 billion in the next 20 years could avoid losses of $135 billion over the lifetime of those measures. Entergy’s customer region was the study’s focus area.

As for agriculture, changing rainfall patterns, higher temperatures in warm seasons and colder weather in cool seasons will affect crops and livestock, said Bobby Fletcher, Jr., Southeast regional director at LSU AgCenter. Crop production will be influenced by more tropical storms. Agriculture, however, is among the sectors most able to adjust to increased heat, pests, water stresses, diseases and other extremes. “Crops and agricultural management practices will likely adapt to changing temperatures, but we may need increased irrigation during extreme hot or dry months,” Fletcher said. Louisiana’s Dept. of Agriculture and Forestry manages wetlands re-vegetation, reforestation and forest stewardship programs.

Local flora and fauna have already been touched by climate change. “High temperatures have allowed invasive species of animals and plants to compete with our native species,” Burkett said. “The rodent nutria has expanded in range, partly because of milder winters in the past few decades.” Nutria, imported in the 1930s by the McIlhenny wildlife refuge in Avery Island near New Iberia, gnaw away at plants that stabilize the coast. “They’re now found in Arkansas and up the Atlantic coast,” she said. State and federal agriculture, forestry and fisheries agencies and Louisiana Sea Grant—which provides coastal resources stewardship—all monitor invasive species.

Construction is one way to adapt to climate change. Carol Franze, area agent with Louisiana Sea Grant and LSU AgCenter, said “local governments are recognizing a need to build stronger homes and businesses, and to locate these and other infrastructure out of harm’s way—whether it’s above the base flood elevation or out of flood zones entirely.” Sea level rise and storm surge are placing many coastal areas at risk for erosion and flooding, she noted. “Louisiana Sea Grant-LSU AgCenter has been working with local governments to identify risk infrastructure and to find ways to mitigate flooding from land loss and storm surge.” She has been part of that initiative, called Coastal Community Resiliency, since 2008.

Because of climate change, Louisiana residents can expect more public health risks from storms, flooding and waterborne illnesses, drought, heat waves and declining air quality, according to the Natural Resources Defense Council in New York. Heat, rain and humidity help spread infectious diseases as pathogens come in closer contact with humans. Louisiana’s cases of West Nile virus, a mosquito-borne pathogen, have fallen from high levels early this decade, however, possibly because of more spraying. The Louisiana Dept. of Health and Hospitals has an environmental tracking program, collecting and distributing public health data to guide policies.

At Louisiana State University, Ed Overton, emeritus professor of coastal sciences, said “climate change is very controversial, with strong opinions on both sides of the issue as to how severely the climate is changing.” Predicting the effects of change is difficult. And he said “most of us, including myself, are not climate scientists and aren’t in a position to understand all the associated issues.”

But, Overton said, “we all agree that sudden change is the worst case, while gradual change gives communities time to adjust to new realities.” Land loss in Louisiana, caused by a number of factors, is affecting both the landscape and the ability of communities to earn a living, he said. However, it’s occurring at a rate that allows adjustment, including efforts to slow or even reverse land loss in small selected areas.

“Change to some of our community structures and lifestyles is inevitable,” Overton said. If sea level rise is severe, south Louisiana and much of the coastline along the Gulf will be changed. “New Orleans, for example, could be a manmade, protected island along the coast of the northern Gulf,” he said. “This won’t happen in our lifetime, but it’s certainly within the realm of possibilities. However, if that occurs, it will be slow and will allow for adaptation.”

In probably the biggest, local effort to adapt to climate change, the U.S. Army Corps of Engineers has spent billions of dollars in Louisiana — its most heavily funded state — for flood protection since Hurricane Katrina.

This article was originally published in the October 24, 2011 print edition of The Louisiana Weekly newspaper