Scientists are gaining a better understanding of why, no matter the severity, many residents won’t heed orders to evacuate

Early Friday morning, Sept. 14, Hurricane Florence made landfall as a Category 1 storm near Wrightsville Beach, North Carolina. Although the storm has lost some of its offshore strength, it’s still considered highly dangerous by authorities and is already causing severe flooding. By Thursday, North Carolina officials had issued evacuation orders in 16 vulnerable counties. Some are voluntary, but most are mandatory, covering around 1 million people, according to the state’s Department of Public Safety (DPS).

But, as in the cases of Harvey, Maria, Katrina, and other recent high-profile hurricanes, many people have chosen not to follow evacuation orders, putting themselves and emergency responders at risk. Keith Acree, a North Carolina DPS spokesperson, said the state has no way to monitor exactly how many people evacuated ahead of Florence, although he reported a steady stream of inland-bound traffic.

As climate change increases the severity and frequency of catastrophic storms, emergency management authorities are looking for new ways to motivate people to take precautionary action. The answer may be more psychological than technological. Over the last decade, meteorologists have made huge strides in precision weather forecasting, but it hasn’t proven to be enough to get more people to move themselves out of harm’s way, said Jennifer Marlon, an environmental scientist at Yale. “We need to invest in communication,” Marlon said. “There’s a recognition that what’s going on in people’s minds is as important as us getting the models right.”

Marlon is part of a growing group of researchers studying the science of disaster risk perception: how people understand their own exposure to hurricanes, wildfires, and other natural disasters, and what they choose to do about it. In other words, what motivates some people to pack up and leave at the first sign of trouble and others to fill their bathtubs, board up their windows, and hunker down? And what’s the best way to connect with the holdouts?

What scientists are finding, said Marlon, is that in the case of hurricanes, people often misunderstand the danger they’re in, and they lack sufficient information to exercise good judgment.

“To obfuscate about the reality of the science leaves people unprepared.”

People tend to underestimate the risk of flooding and storm surge, Marlon said. For example, “there’s a broad misconception that wind is the danger you need to worry about,” she said. “But flooding is what kills the most people.”

In 2014, two years after Superstorm Sandy wracked New York City and the surrounding region, Marlon led a survey of more than 1,000 residents of coastal evacuation zones in Connecticut. She found the respondents broke down into five groups that represent a gradient of willingness to evacuate: first out, constrained, optimists, reluctant, and diehards.

Audience segmentation analysis like Marlon’s has a long history in marketing, but it’s still in its infancy in disaster communications. Still, scientists like Marlon are learning it’s essential for understanding what messages click with certain groups of people.

Figuring out what motivates people to evacuate versus stay home reveals, among other things, a few key barriers to evacuation, including health issues, cost, and even whether people have pets or not. A separate 2011 study from Florida International University pegged the per household cost of evacuating from a Category 3 hurricane to be up to $525, which may be out of reach for many people.

Marlon’s research also suggests that education is a major factor. Those in the “first out” group tended to be more cognizant of the risk of flooding and understood that they lived in a floodplain, whereas more reticent groups were less likely to understand these factors, suggesting that education on hurricane risks in advance of a particular storm can be effective in convincing people to follow evacuation orders.

Messaging from authority figures, like local police or the governor, are much more effective than messages from the news media, Marlon has found. Role-modeling is also important: In a statement to the local news, for example, data suggests a police chief should talk about evacuating their own family, rather than haranguing residents to evacuate themselves. Fear-based messages—like images of roiling floodwaters and flattened houses—are less effective than practical tips, like how to pack a go-bag.

When climate change enters the mix, everything becomes more complicated, said Wanyun Shao, a geographer at the University of Alabama who studies disaster risk perception in the hurricane-prone Gulf Coast. She’s found through her research that talking about climate change as a global phenomenon doesn’t do much to sharpen peoples’ risk perception—and in Republican-majority areas where climate change is politically polarized, it may even lead people to deliberately ignore risk. “Instead, talk to people about the specific manifestations of climate change that resonate and manifest with them,” she said.

Risk perception also tends to be backward-facing, said Shao. Ask someone to imagine their vulnerability to a future storm, and they’re likely to picture the last storm they experienced. That’s not especially helpful in a world where storms are increasing in frequency and intensity, and it may be especially dangerous in a place like North Carolina, which has a rapidly growing coastal population full of hurricane greenhorns.

“There are large numbers of people on the North Carolina coast who have not experienced big coastal storms and who don’t have that contextual awareness,” said Gavin Smith, director of the Coastal Resilience Center at the University of North Carolina.

“There’s a recognition that what’s going on in people’s minds is as important as us getting the models right.”

Moreover, the University of Alabama’s Shao said one of the most effective means of communicating hurricane risk are flood insurance maps produced by the Federal Emergency Management Agency (FEMA), which are often outdated and do not reflect scientists’ most current sea-level rise projections. Shao points out that some neighborhoods in Houston are already rebuilding in areas damaged by Hurricane Harvey without investing in adaptive measures like home elevation or flood insurance because the flood risk maps they’re using don’t accurately portray future risk.

FEMA also only requires homeowners to purchase flood insurance if they live in the highest-risk areas, which often gives people living immediately outside those areas a false sense of security that doesn’t match the real risk, said Rachel Cleetus, a climate policy director at the Union of Concerned Scientists.

“To obfuscate about the reality of the science leaves people unprepared and communities grappling with this on their own,” said Cleetus.

Still, there are signs that more people are making the connection between global warming and their own personal risk, said Marlon. Since 2008, her team at Yale has collected public opinion data on a variety of climate change issues, and the team always finds a considerable gap between the number of Americans who believe climate change is happening (70% in 2016) and those who believe it will harm them personally (40%). To be sure, the latter figure is rising quicker than any of the poll’s other questions, she said. “People are understanding it’s not future generations, and it’s not just polar bears. It is affecting us,” she said.

That message isn’t reaching everyone in North Carolina yet: Within the first few hours of Hurricane Florence’s landfall, several hundred people already had to be evacuated from flooded coastal towns. – Tim McDonnell