Guardian: Flood risk to 2bn by 2050, says study

"Floods already affect more than 520 million people worldwide every year. Torrential rains and rising rivers damage crops, sweep away roads and bridges, flood homes and claim around 25,000 lives. Far more live in the path of once-a-century type floods.
But experts calculate the numbers at risk will more than double because of more frequent extreme weather events linked to global warming, because sea levels will continue to rise as glaciers melt, and because the clearing of forests means rainfall runs off faster."