Climate Change Could Threaten 150 Million

PARIS, Dec. 4, 2007 — -- The number of people threatened by coastal floodingcould more than triple by 2070 due to climate change, while thefinancial impact of flooding could increase by tens of trillions ofdollars, according to a report released Tuesday by the Organizationfor Economic Cooperation and Development.

The Paris-based OECD, an international non-governmentalorganization that collects and studies economic statistics andsocial data, called for quick action on coastal defenses for citiesat risk, saying it can take 30 years to build defenses forvulnerable cities.

About 150 million people could be exposed to coastal flooding by2070 -- up from 40 million now, according to the report. Thestatistics were based on a "1-in-100-year" flooding event,described as a commonly accepted risk assessment standard, with amean rise in sea level of a half-meter (1.6 feet).

The study estimated the financial impact of such a scenario at$35 trillion, compared to $3 trillion today.

The report pointed to the development of Asian "mega-cities,"with their soaring populations, as a key factor increasing the riskin coastal flooding.

Calcutta heads a list of the 10 top cities at risk in 2070 interms of population exposure, with Mumbai, or Bombay, second.Miami, Florida, in ninth place, was the only city in a developedcountry on the report's list of the 10 top cities at risk due topopulation exposure.

However, Miami leads the list of cities with the highest valueof property and infrastructure assets at risk in 2070 should that"1-in-100-year" flood occur, the report said. Miami also leads inthat category today.