A tour bus was swept up in a flash flood in northern Arizona on 28 July 2013, according to the Northern Arizona Consolidated Fire District No. 1. Photo: Northern Arizona Consolidated Fire District No. 1

By John Roach
19 August 2013

(NBC News) – Flood damage in the world's major coastal cities may top $1 trillion a year by 2050 due to rising seas and subsiding land, according to a new study.

The startling figure is "not a forecast or a prediction," but rather a means to "show that not to adapt and not to improve protection is impossible," Stéphane Hallegatte, a senior economist with the World Bank in Washington, D.C., and the study's lead author, told NBC News. "We have to do something."

The finding, which comes nearly 10 months after Superstorm Sandy's destruction, is shared by Hallegatte and colleagues in a report Sunday in the journal Nature Climate Change. Researchers considered current flood protections in 136 cities around the world, and found that in many instances they are inappropriate for sea levels that rise a projected 8 inches by the year 2050.

Many of the most vulnerable cities are in the U.S. Miami, New Orleans and New York, for example, account for 31 percent of the global aggregate losses in the 136 cities, making it stand out even from the world's other developed countries.

This may be because "the U. S. has trouble financing infrastructure, not only for coastal protection, but also transportation," Hallegatte said. That could be a reflection of how government functions in the U.S. with local, state, and federal agencies responsible for different aspects of infrastructure projects, he said. Whatever the reason, the finding illustrates that flood-reduction actions in a few places could be cost effective, he and colleagues said in the paper.

With global investment of about $50 billion a year in flood-protection measures such as higher sea walls and levees, much of these losses can be avoided, Hallegatte added. "It is a very good investment in financial terms," he said. "But if you look at who will pay and how we will pay for that, then it gets difficult."

Even with with flood protections in place, the annual costs in losses to flooding by 2050 will still be a significant $60 billion to $63 billion, the report said.

Inappropriate flood protections are actually worse than no protection at all, Hallegatte said. That's because a too-short sea wall, for example, provides a false sense of security, emboldening people who live behind it to build more densely than they otherwise would. When the flood hits, there is more to lose.

"These are scary numbers and they are likely to be underestimates," Mike Beck, a marine scientist with The Nature Conservancy who studies coastal impacts from flooding, told NBC News. He was not involved with the new study. [more]

Increased flooding may cost the world $1 trillion by 2050



Blog Template by Adam Every . Sponsored by Business Web Hosting Reviews