To teach a new course on climate change, I have to study an awful lot of publications. Endless tables of data and diagrams with jagged lines are available, suggesting ever-increasing temperature trends. Amid all the measurements and calculations, I miss solid information about what places in the world will be the most vulnerable. This is what one might call the geography of climate change, and I don’t see it in any textbooks yet.
Towns on an ocean or sea shore are impacted strongly by sea level rise. Even a mild coastal storm can produce widespread flooding if the elevation is only a few feet above the high water mark. But a tropical system like the ones we had this year, comparable to Beta, Eta, Zeta and anything else that rhymes with this, will produce a storm surge. That’s the rise of ocean water under the low air pressure of the storm. Wind, which is strongest some miles away from the storm’s center, will pile additional waves on top of that. If the location is in a bay, where approaching waves find less and less space to move into, the water rises most quickly. Now suppose the town is located on an ocean shore, at elevations near sea level, at the end of a bay, and with mountains nearby. This will put the location in quadruple jeopardy. I was reminded of the city of Gonaïves, Haiti, whose location fits that description. In 2008, hurricane Hanna swept waves into the bay. But the nearby mountains, up to 2,000 feet tall, caught more rain, and rivers brought it down into the city. The result was a devastating flood.
A similar town that meets these criteria is Laoag City (population 105,000) in the Philippines. In August, 2015 Typhoon Goni killed 10 people and put the town under water. Just 5 years later, another Goni came around, locally named Ulysses. Luckily for the city, the 2020 typhoon passed farther south.
The impact of severe storms like the 2020 examples of Laura, Sally, Eta, Iota, Goni and Vamco depends heavily on the geography of the locations visited, as well as the whims of steering winds that may favor one place but spare another. In the U.S., these geographic criteria should put San Diego, Los Angeles and San Francisco in a prominent place on the watch list.
Rudi Kiefer, Ph.D., is a professor at Brenau University, teaching physical and health sciences on Brenau’s Georgia campuses and in China. His column appears Sundays and at gainesvilletimes.com.