Will the Pakistan floods strike again?

Howard Falcon-Lang in the BBC: The recent floods in Pakistan's Indus Valley are of truly Biblical proportions. The UN estimates that the humanitarian crisis is now larger than the combined effects of the three worst natural disasters to strike in the past decade.

These include the Asian tsunami and the major earthquakes that devastated Kashmir and Haiti. The headline figure of 1,700 killed masks the real scale of the disaster that has displaced 14 million people.

As I write, the southern city of Hyderabad, with a population of 1.5 million, stands on the brink of inundation as peak floodwaters surge downstream. Scientists have described this catastrophe as a once-in-a-century flood. But could climate change mean that floods of this magnitude, or even bigger, become a more regular occurrence?

The Indus is one of the world's great rivers. From its headwaters in the Himalayas of Tibet, it flows north-west through India before turning sharply south across Pakistan. It finally discharges into the Arabian Sea, a journey of some 3,200km (2,000 miles).

Although some of its water comes from melting Himalayan glaciers, the vast majority is dumped by the summer monsoon....

Monsoon rains enabled the usually calm Kabul River to sweep away entire buildings in early August 2010. By August 6, intense rains in the Swat Valley of northern Pakistan had subsided somewhat, leaving behind fields of mud to bake in the summertime heat. NASA