While Pakistanis count the cost of one of the country's worst recorded floods, heavy rain is hitting southwestern China as the Texas city of Dallas recovers from a 10-inch deluge in a single day last month.
Each of these rain-fuelled disasters followed a heatwave, suggesting the regions have been swinging wildly between two contradictory extremes. But extreme heat and extreme rainfall are closely related - and being gassed-up by climate change, scientists say.
