Quotes of the Day

Heavy rainfall during south asia's summer monsoons typically swamps large swaths of the subcontinent, but this season's storms have been unusually fierce. Four monsoon depressions, double the usual number, have caused the worst flooding in memory in parts of Pakistan, India, Nepal and Bangladesh. Nearly 800 have died and upwards of 20 million have been forced from their homes; aid agencies are warning that the death toll could rise because the scale of the disaster has overwhelmed efforts to reach stranded villagers with food, drinking water and medicine to combat outbreaks of malaria and dengue fever. Waters were receding in some areas, but forecasters say more downpours may be on the way.

India's Meteorological Department says it can't link the floods directly to global warming but the number of "extreme rainfall events" is definitely on the rise — a fact confirmed by the World Meteorological Organization (WMO), which reported that 2007 has been marked by extreme weather not just in South Asia but worldwide. Examples: South Africa and parts of South America have experienced freak snowfalls in recent months, while heat waves across Russia and Southern Europe set new high-temperature records in some cities; the U.K. and Germany were hit by spells of torrential rain exceeding any in more than a century. The WMO, a branch of the U.N., says the global average for land-surface temperatures in January and April were likely the warmest since records began 127 years ago. Parts of the planet that have been spared weather-related misery may not be lucky for long. The Intergovernmental Group on Climate Change says it's "very likely" that heat waves and heavy precipitation will occur with increasing frequency in years to come.

• Simon Robinson