Extreme weather forecasts can save lives — but only if people listen and respond. The best forecast is useless if people don’t act on the information, a reality that applies as well to emergency alerts. So we did a roundup on what experts are saying about why people ignore or respond inappropriately to weather warnings.
Normalcy bias or optimism bias
Normalcy bias, or normality bias, is a cognitive bias which leads people to disbelieve or minimize threat warnings. Consequently, individuals underestimate the likelihood of a disaster, when it might affect them, as well as its potential adverse effects
Normalcy bias makes it difficult for us to engage in “worst-case” thinking and plan for a serious failure or disaster. This kind of bias causes people to assume that, although a catastrophic event has happened to others, it will not happen to them. People often base their decisions on previous experiences, such as other storms they’ve lived through.
Part of the challenge is that forecasts are uncertain, so the area covered by a warning is necessarily larger than the area that’s actually affected. Most people who receive warnings don’t experience the actual event, which can cause them to discount future warnings. For tornadoes, for example, meteorologist Dr. Kim Klockow-McClain puts it this way, “Even within a given event, less than 1 per cent of the spatial extent of a tornado-warned area will actually experience a tornado, and about 70 per cent of all tornado warnings will result in false alarms.”
The consequences can be deadly. In 2011, one of the deadliest tornadoes in US history in Joplin, Missouri, killed 158 people and injured more than 1,000 others. NOAA’s assessment of the relevant NWS warnings and forecasts found that some residents had become desensitized, and that “initial siren activation has lost a degree of credibility for many residents.”
About 70% of people reportedly display normalcy bias during a disaster. The normalcy bias can manifest in response to warnings about disasters and actual catastrophes.
The challenge of “probability” and how people process information
Translating weather risks and emergency alerts into terms the public can understand is important, but difficult.
Dr. Marshall Shepherd – director of the University of Georgia’s atmospheric sciences program – talked about this challenge on an NPR podcast “The Science of Extreme Weather” (The Pulse : NPR).
For example, he talked about the “cone of uncertainty” – the projected path and intensity of a hurricane or tropical storm – a concept that can be hard for people to wrap their heads around and is often misconstrued. The cone suggests a 2 out of 3 chance that anywhere within that cone will be the center of the storm. For many people, this is not an easy idea to grasp.
In one example, a TV reporter went to grocery stores in Sarasota, Florida, 3 days prior to Hurricane Ian making landfall to see how people were preparing. The folks she interviewed were “just doing their regular shopping”. Nobody seemed especially worried. Sarasota was in the “cone of uncertainty”.
Some experts believe that most people do not ignore the information they get in warnings. Dr. Jen Henderson, with the Cooperative Institute for Research in Environmental Sciences says, “…from the interviews and focus groups we’ve done, people are not complacent. They’re all taking action, it’s just not the actions we’d expect or we can see.” Julie Demuth at the National Center for Atmospheric Research agrees: “For the most part, people don’t disregard weather warnings. But that doesn’t mean they’re always going to do what we want them to do.”
As a practitioner, it’s worth noting that the academics don’t all agree. Dr. Shepherd thinks the public and policymakers need to be trained on how to consume information better. But Susan Joslyn, associate professor of psychology at the University of Washington disagrees. She studies the way people make choices when given weather information. “People can’t absorb and use information unless it’s tailored to how they’re thinking about it and their decisions. To evacuate or not.” Professor Joslyn believes that people can handle more complexity than they are given credit for.
Despite the lack of consensus, we can hope that continued research will help make information more relevant and impactful. As an article on the Weather Network puts it: “Bridging that gap — between basic weather information and peoples’ response to it — is a key area of research for the future of severe weather communication…”
There’s no easy solution to the challenges here. Data from the 2020 NHS Data Digest, suggests that the rate at which the adult population becomes prepared or maintains preparedness for emergencies has stalled over the years, despite the fact that extreme weather events are becoming more common and more extreme. So there’s a critical need to encourage, guide, and assist individuals and communities to move from thinking about a potential emergency and actually doing something about it.
One benefit of emergency alert systems such as Hyper-Reach is that you can deliver information to residents in a highly localized and specific way. And you can use the alert system to tell residents exactly what actions you want them to take.
Greater precision might give you the ability to communicate more effectively with the public. Dr. Joslyn’s research shows that most people can understand numeric likelihoods, so that if they’re told there’s a 20 or 30 percent chance of something happening, they make better decisions than they might have made without this information.
Joslyn’s work implies that it’s better for people to have the numeric information because they’re going to make their own estimates anyway, based on past experiences. If they’ve experienced false alarms in the past, they may end up underestimating the risk, but more accurate information about risks and uncertainty can reduce the misestimating – and that could save lives.