Global climate implications [1]

The past decade has witnessed the warmest years on record with a 0.7 degree Centrigrade increase over the last century.

According to the IPCC, destructive heavy precipitation events, as well as intense tropical storms, are likely to increase as a result of global warming. [2] This will be coupled with increased unpredictability in climate events and more extreme weather than witnessed in the past. The ability of a community to cope and recover from more frequent and intense storms and floods is limited, and the net effect of these repeated climatic events is to compound existing vulnerabilities. For example, the coast of Madagascar and Mozambique was hit by five successive cyclones between December 2006 and March 2007, often affecting the same areas and causing waves of displacement.

Nearly 634 million people – one tenth of the global population – live in at-risk coastal areas just a few meters above existing sea levels. Three quarters are located in Asian flood-prone densely populated river deltas or in low-lying small island states.  Many of the world’s largest cities, including Mumbai, Calcutta, Karachi, and Buenos Aires, are at risk of coastal flooding [3] and almost two-thirds of mega-cities with populations greater than 5 million fall at least partly, in low-lying flood-prone areas. [4]   In the last 20 years the recorded number of disasters caused by floods has increased by 300 percent from about 50 to more than 200. In terms of humanitarian response, floods and storms now make up the bulk of sudden onset international disaster responses. Of the 26 Flash Appeals that have been issued since January 2006, 18 have been in response to floods and cyclones.

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[1] This document focuses on flood and cyclone events, however it should be noted that the intensification of climatic extremes associated with climate change will also increase both the likelihood and geographic range of drought and desertification.
 
[2] Climate Change 2007: Intergovernmental Panel on Climate Change, Fourth Assessment Report.
 
[3] Munich Re (2005) in Stern Review (2006)
 
[4] McGranahan, G., D. Balk and B. Anderson. Forthcoming. "The Rising Risks of Climate Change: Urban Population Distribution and Characteristics in Low Elevation Coastal Zones." Environment and Urbanization