Report: Greenhouse gas impacts evident on coastal Louisiana

Climate Report
Climate Report

More hot days, larger piles of debris from hurricane storm surge and the increased vulnerability of communities and industry along the Gulf Coast as sea level continues to rise are just a few of the effects happening now in Louisiana due to climate change, according to a new federal report.

Those effects are expected to continue unless changes are made in releases of greenhouse gases, authors of the report said.

The U.S. National Climate Assessment’s report Tuesday states that Louisiana is already seeing an increase in the number of days when temperatures get above 95 degrees, and the region will continue to see coastal vulnerability increase as sea level continues to rise and the land continues to sink.

“Based on sea level rise trends, today’s occasional floods are tomorrow’s high tides,” said Kristin Dow, professor of geography at the University of South Carolina and one of the report’s authors. “Climate change is happening here in the Southeast and we’re feeling the effects.”

Sea level rise also is expected to continue, which puts the roads, cities, airports, oil and gas facilities as well as ports at greater risk to flooding.

For example, Dow said, Port Fourchon supplies a large amount of the offshore oil and gas industry in the Gulf of Mexico, but there is only one road that supplies this port.

Relative sea level rise, which combines the sinking land and rising water, means that La. 1 is vulnerable to flooding, which shuts off this vital facility.

“The Department of Homeland Security estimated that a 90-day closure of this road would cost the nation $7.8 billion,” according to the report.

The report is the product of more than 300 authors with the oversight of a 60-member National Climate Assessment and Development Advisory Committee looking at climate change effects occurring now in the United States and what can be expected for the future. The report also highlights that this climate change is occurring because of human activities, primarily in the form of burning fossil fuels, which releases greenhouse gases. The report is required every four years under the U.S. Global Change Research program established in 1989 by presidential initiative and by Congress in 1990.

Nationally, the climate change has been seen in more episodes of extreme weather, such as prolonged droughts or heavier downpours of rain, which can cause localized flooding. Other concerns include an increased frequency of severe storms, fewer frost-free days, ocean acidification and ice melt.

“The Arctic Ocean is expected to become essentially ice-free in summer before midcentury,” according to the report.

In the Southeast specifically, temperatures are, on average, 2 degrees hotter than in 1970, and that increase is expected to continue this century.

The communities of the Gulf Coast also will face rising costs and losses from sea level rise and tropical storms, which will push more water inland. Currently, the Gulf Coast states average about $14 billion in damage from hurricane winds, sinking land and sea level rise, according to the report. Future losses could rise to anywhere between $18 billion a year to $23 billion a year with about 50 percent of the increase related to climate change, the report quotes from a 2010 publication from America’s Wetland Foundation and Entergy.

Although the Southeast, and other regions of the country, face many challenges from the ongoing climate change, there also are opportunities, Dow said. Reduction in the amount of greenhouse gases released, increasing the energy-efficiency of buildings and businesses as well as taking steps to adapt to things like rising sea level are all things that can help communities deal with the changes.

According to the report, “The amount of future climate change, however, will largely be determined by choices society makes about emissions.”

Fewer emissions means less heat-trapping gases, while more emissions means more climate change and related effects.

“All is not lost,” agreed Katharine Hayhoe, director of the Climate Science Center at Texas Tech and one of the report’s authors. “The choices we make today impact what we will have in the future.”

Follow Amy Wold on Twitter, @awold10.