"Climate change is destroying our path to sustainability."
— Ban Ki-moon, former U.N. General-Secretary
Will climate change bankrupt the global economy?
It’s becoming clear that if we continue on our current path, the answer is “yes.” The direct and indirect costs and extensive disruptions caused by climate change cannot be overcome by ordinary economic growth. While volumes can, and undoubtedly will, be written on the multiple effects of climate change on economic vitality, one issue, that of repeated flooding in coastal zones, confirms this reality.
When the recent spate of hurricanes inundated American cities and coastal communities, wildly varying estimates of “rebuilding costs” appeared in the media almost before the storms had passed. But it’s misleading to focus entirely on rebuilding costs, which are only part of the overall costs of dealing with a disaster. What, for example, was the cost of evacuating much of Florida before Hurricane Irma hit? What will it cost to feed a large portion of Puerto Rico’s population for a year or so until the island’s economy can recover from Maria?
But the larger question is, “What’s the cost of rebuilding, then rebuilding again, then rebuilding again?” In the case of flood damage, repetitive rebuilding could be needed in the coming years and decades.
The anticipated flooding will have three causes: human development in flood zones and filled wetlands, extreme weather events and sea-level rise. Lowland development is likely to continue in the short term — cities seek development, often irresponsibly, and developers seek quick, fat profits. Meanwhile, extreme weather is increasingly exacerbated by climate change and rising sea levels are driven almost entirely by increasing temperatures. Whenever superstorms hit low-lying cities, which is increasingly likely from now on, serious flooding can be expected. And even if no more superstorms arrive, which is extremely unlikely, sea-level rise will ultimately inundate all of the world’s coastal regions.
Acknowledging these realities, some analysts have called for adaptive policy changes. Proposals include building sea walls, dams, catchments and culverts, financed by various schemes but ultimately by the public. Since most of these ideas have yet to reach the design stage, their potential costs are hard to estimate. But it would certainly cost billions of dollars to build an effective flood control system for just one city — say, Houston — and any such expenditure would be added to the cost of repairing Hurricane Harvey’s damage.
Worse, such measures are unlikely to work in the long run. As sea levels continue to rise, so must sea walls, until they reach ridiculously expensive heights.
Perhaps a more realistic approach would be to systematically abandon flood-prone coastal zones altogether. After Hurricane Sandy, New York state initiated a program (using federal funds) to buy houses in vulnerable coastal flood zones and demolish them, hoping former wetlands, displaced by the housing, would recover and act as buffers against flooding. They bought approximately 500 homes from owners who were tired of floods and glad to have a buyer for their vulnerable, depreciating properties.
While abandoning much of America’s (and the world’s) coastlines is the “wave of the future,” continued government buyouts are not; they are simply unaffordable at the needed scale. A NASA map of Florida in the year 2100 shows the projected loss to the ocean of the entire southern third of the state and virtually all of its coastline. Beginning soon, U.S. coastal property owners will simply lose their equity as they retreat to ... somewhere.
Wherever they migrate — to desiccated U.S. interiors or the barren Canadian Shield — their poverty is likely to increase as they compete with locals and other migrants for dwindling resources. For flooding is only one of many threats to the global economy at our ecological house.