By Karen Savage
Climate change is to blame for about $67 billion of the economic damage caused by Hurricane Harvey, a total far higher than previously thought, according to a study published earlier this year in the journal Climate Change.
Hurricane Harvey tore through parts of the Caribbean before making landfall on the Texas-Louisiana border as a Category 4 hurricane in 2017. The storm dumped more than 50 inches of rain in some areas and caused extreme flooding. Varying estimates put the total economic cost between $85 and $125 billion.
The researchers pointed out that Harvey’s climate-related damages alone far exceed the $21.3 billion the Environmental Protection Agency said climate change costs the U.S. annually.
Nearly half of Houston’s homes sustained some type of damage. Thousands across south Texas remained displaced nearly two years later. Scientists determined that 38 percent—or about 19 inches—of the rainfall can be attributed to climate change.
“I think the main contribution we’re making is by really trying to link those impacts that are damaging people’s lives with more forensically understanding the human contribution to those events,” said the study’s lead author, Dr. David Frame, who is director of the New Zealand Climate Change Research Institute at Victoria University of Wellington.
The ability to put a price tag on extreme weather events could help municipalities seeking to hold fossil fuel companies liable for climate change-related impacts.
Frame said while more research is needed, at least one non-governmental organization in Europe is hoping to use the study as evidence in climate change-related litigation.
This study, combined with other recent research, shows the costs already levied by climate change, said Jessica Wentz, who has written on climate change attribution as a non-resident senior fellow at Columbia University’s Sabin Center for Climate Change Law. She said it shows climate change can no longer be framed as a future threat.
“It’s something that’s happening right now, affecting people, economies, ecosystems right now, and I think that sort of message is powerful in litigation,” Wentz said.
“I do think that the defendants in these cases, particularly fossil fuel companies, are probably quite concerned about the advances in science and the ability to trace emissions both to their activities and the ability to then scale down to actual impacts and human injury.”
The liability suits—more than a dozen of which have already been filed across the country—seek to hold fossil fuel companies accountable for those costs. The municipalities argue that the industry has long known its products are the overwhelming driver of global warming and have worked hard to obscure that fact to the public.
The Harvey research, along with a separate study by the same researchers examining climate change-related damage during extreme weather events in New Zealand, is unique because researchers calculated the odds that an extreme weather event would occur, then plugged in the average estimated economic damage costs of that event.
Models used previously have focused primarily on the weather event itself, evaluating the extent to which climate change has influenced the likelihood or severity of those events.
“We see [the Harvey and New Zealand] papers mainly as plugging two literatures into each other—disaster economics and event attribution,” Frame said, adding that there’s currently a gap between calculations used to inform climate policy and the actual damage being done by climate change during extreme weather events.
Frame said the specific dollar amounts—which are uncertain because the methodology is still new—are less important than how the values compare to previous calculations.
“It was striking how high those numbers were,” Frame said. “If you begin to consider them across all the other events—and that’s kind of really want to take this literature, we want people to start doing these studies, economists working together with climate researchers to develop the stuff, and then compare them with the numbers people have been using for policy—I’m pretty sure that you’d get a much higher social cost of carbon and that would justify a lot more action on climate change.”
The gap in damage calculations also means the financial risk posed by climate change could be far higher than previously thought.
“Companies potentially, and consumers, have more to lose by reckless or by negligent action on climate,” Frame said. “So just simply pretending climate change is not a problem will be a higher risk in the future than it has been to date.”