Few would be surprised if President Obama took aim at climate change during his visit Tuesday to survey the Louisiana flooding, which is why global warming skeptics are already raining on his parade.
The climate blame began in earnest last week with former Vice President Al Gore, who described the deluge as an example of “one of the manifestations of climate change.” Those remarks were followed by a rash of supportive articles.
“Flooding in the South looks a lot like climate change,” said an Aug. 16 headline on an article in The New York Times.
The Green Party of Louisiana issued a statement Friday calling the flooding “further evidence of the global crisis posed by climate change.”
“Until humans make global, sweeping changes to our economic and social systems, we must expect these types of disasters to continue regularly,” said the party. “The Green Party of Louisiana calls for the rapid elimination of the fossil fuel economy.”
Green Party presidential candidate Jill Stein called Saturday for declaring a “climate state of emergency,” saying disasters such as the Louisiana floods and California wildfires “are going to become day-to-day occurrences.”
Meteorologist Eric Holthaus, who hosts the Warm Regards podcast, wrote in an op-ed Sunday in Newsweek: “When no-name storms have the ability to become 500-year scale disasters, we should know we’ve reached a new meteorological era.”
The problem for skeptics lies in the proof. While warmer temperatures generally result in more precipitation, the Cato Institute’s Chip Knappenberger said, the scientific evidence needed to attribute the Louisiana flooding to human-caused increases in atmospheric greenhouse gases simply doesn’t exist.
“The science is not there to link this definitively to climate change,” said Mr. Knappenberger, assistant director of Cato’s Center for the Study of Science.
He and Cato’s Patrick J. Michaels pointed to two recently released studies showing that “attributing heavy precipitation events in the United States to human-caused climate change is a fool’s errand.”
An Aug. 10 paper by University of Iowa scientists found that while the number of storms is increasing, “the stronger storms are not getting stronger” and that natural variability driven by the Pacific and Atlantic oceans “can exert a large control on the precipitation frequency and magnitude over the contiguous USA.”
A second study on heavy rainfall events published Aug. 8, led by researchers at the NOAA/Geophysical Fluid Dynamics Laboratory, concluded, “In part because of large intrinsic variability, no evidence was found for changes in extreme precipitation attributable to climate change in the available observed record.”
Heritage Foundation fellow Nicolas Loris pointed to the most recent report by the United Nations Intergovernmental Panel on Climate Change, which cited a “lack of evidence” to support the contention that floods are increasing in frequency or magnitude on a global scale.
“For the Al Gores of the world, it’s convenient to point to the Louisiana floods, Superstorm Sandy, Hurricane Katrina or the tornado in Joplin, Missouri, as evidence of man-made global warming,” Mr. Loris said in The Daily Signal. “The facts, on the other hand, are inconvenient.”
Storms that began Aug. 5 in Louisiana sent floodwaters into more than 60,000 homes in 20 inland parishes, as well as the cities of Baton Rouge and Lafayette, resulting in 13 deaths and thousands of displaced residents.
For Mr. Knappenberger, the problem is that too many variables are involved to link extreme weather events such as hurricanes and flooding to climate change.
“Some people say climate change is involved in every event. It is involved in every event, but how it’s involved in every event is beyond our comprehension right now,” he said. “It’s just not fair to say that it makes, quote, ‘bad’ events worse. That’s what they will have you believe, and that’s what Al Gore’s doing here, but it is far from scientifically proven or demonstrated that that is the case.”
Chalking up the Louisiana flooding to climate change is especially problematic. The region is known for its periodic downpours, such as a 1962 tropical depression that dumped 23 inches of rain on the state in three days.
“The fact is that these events can occur without climate change under a similar set of conditions — the Gulf was warm back then, and it rained a lot — so you don’t need climate change to explain heavy rains in that part of the country,” Mr. Knappenberger said.
Mr. Obama, who is slated to tour the region Tuesday, has made fighting climate change a hallmark of his administration, particularly in the past two years with emissions-cutting initiatives such as the Clean Power Plan.
He came under intense pressure last week from flooding victims and others, including Mr. Holthaus, to cut short the annual Obama family vacation in Martha’s Vineyard to visit Louisiana.
“Words matter,” Mr. Holthaus said. “And since Obama has staked a big part of his legacy on climate change, he owes it to the victims of the flooding in Louisiana, and the potential victims of future climate-related disasters, to address the clear and present threat of climate change directly in Louisiana.”