Hurricanes kill far fewer people today than they did in the past. When the Galveston Hurricane hit Texas in 1800, it claimed 8,000 lives. The Galveston Hurricane has the highest death toll of any hurricane in U.S. history not because it was stronger than any of the hurricanes we see now, but because it occurred during an era when people were less capable of predicting and weathering hurricanes than they are today. In comparison, Hurricane Katrina in 2005, one of the worst natural disasters in the U.S. in recent years, claimed 1,800 lives. Elsewhere in the world, improvements in emergency procedure and infrastructure are still needed to reduce death tolls, but we’re on our way there. That’s the good news. The bad news is that we are still very vulnerable to hurricanes.
Hurricanes are among the deadliest of natural disasters. In Southeast Asia, Pacific hurricanes killed 740 people a year on average between 1990 and 1998. In the U.S., which is less vulnerable for several reasons (including a less active Atlantic basin) the annual average death toll was 50 for the years between 1963 and 2012. Note, however, that averages conceal enormous variability. A single hurricane, the Great Bhola Cyclone, killed almost half a million people when it struck Bangladesh in 1970. When Hurricane Katrina hit the US in 2005, it accounted for more than 40 percent of the hurricane-related deaths in the entire 50-year period. Overall, about one percent of the storms that hit the U.S. between 1963 and 2012 accounted for two-thirds of all the fatalities.
Hurricanes kill in multiple different ways. Wind is interestingly responsible for only eight percent of storm-related deaths, at least in the U.S. Water, on the other hand, has historically caused 90 percent of deaths, most of which (49 percent of the total) are specifically attributable to the phenomenon known as “storm surge.” As a hurricane churns across the ocean, its winds blow strongly enough to fill the air with sea spray and push the water into a wall in front of the storm. This wall of water piles higher and higher as the storm enters the shallow water near the shore, and by the time the hurricane hits, it may flood the land with anywhere from four to more than 18 feet of water. Damage depends on the timing of landfall—particularly if a hurricane hits during high tide—and the topography of the coast. The greater the area of shallow water approaching the coast, the larger the storm surge. If the tide is high when the hurricane hits, that also boosts the water level. At its high point in the town of Waveland, Mississippi, Hurricane Katrina’s storm surge was 40 feet.
For Katrina, during which levee failures exacerbated the danger of the storm surge, as well as for other deadly U.S. storms like Betsy in 1965 and Sandy in 2012, storm surge was the primary cause of death. Unfortunately, that doesn’t mean we can concern ourselves only with storm surge because every individual hurricane is different and poses a different hierarchy of dangers. For instance, Hurricane Camille in 1969 and Hurricane Agnes in 1972 claimed most lives through rainfall-induced floods and mudslides, which are also a serious danger in Japan. Meanwhile, 20 of the 72 deaths caused by Hurricane Sandy were wind-related, resulting from falling trees.
Besides inflicting loss of life, hurricanes also cause loss of livelihood for those in their paths, by destroying communities and damaging property. On average, hurricane damages cost the U.S. 5.2 billion dollars every year between 1990 and 1998. In Southeast Asia, the annual cost averaged 3.1 billion dollars for the same period. Again, most of the damage is usually concentrated in a few especially devastating storms. Hurricane Katrina cost 108 billion dollars in damages, destroyed 68,729 homes, and deprived 3 million people of electricity.
Across the entire world since the year 1900, tropical cyclones have incurred the loss of more than 874,000 human lives and more than 179 billion dollars in property damage. Most of that cost comes immediately upon impact. But the total cost of a hurricane can’t be calculated a day or even a year after it hits. We often pay less attention to the indirect effects of hurricanes, especially since they’re less likely to make the news. But even when the indirect impact is less dramatic than the initial death and destruction, it’s certainly no less serious.