Climate flooding threat 'could treble'

Climate change could treble the number of people threatened by coastal flooding over the next 60 years, one forecaster said today.

The financial impact could surge by tens of trillions of dollars, according to Angel Gurria, secretary general of the Organisation for Economic Co-operation and Development.

He called for urgent action to buy time for cities at risk. It can take 30 years to put defences for vulnerable cities in place, a report published by the organisation said.

“Climate change is already happening and concerted action is needed now to prevent its worst impacts,” said Mr Gurria, who is scheduled to take part in the UN Climate Change conference in Bali next week.

About 150 million people could be exposed to coastal flooding by 2070, compared with 40 million now, according to the report. The statistics were based on a “1-in-100-year” flooding event, described as a commonly accepted risk assessment standard, with a mean rise in sea level of a half-meter (1.6 feet).

The study estimated the financial impact of such a scenario at 35 trillion dollars.

The development of Asian “mega-cities,” with their soaring populations, was pointed to as a key factor increasing the risk in coastal flooding.

Calcutta heads a list of the 10 top cities at risk in 2070 in terms of population exposure, with Mumbai second. Miami in ninth place, was the only city in a developed country on the report’s list of the 10 top cities at risk due to population exposure.