Heatwaves and floods around the world may be a taste of years to come

The recent floods in Pakistan have submerged a third of the country and left more than 1,100 people dead. Monsoon rains, the heaviest in a decade, caused flood surges of more than a metre in parts of the country. It is not the only part of the world to have endured extreme weather this year. Early on, Australia was hit with unprecedented rain and heat. In May record rainfall in Brazil led to mudslides and floods that killed over 100 people. By the summer, east Africa was suffering its fourth consecutive year of drought. Meanwhile, temperature records were broken in cities across Europe, and rivers there ran drier than at any point for 500 years. A 70-day heatwave across much of China saw temperatures regularly exceeding 40°C, with the country’s two largest lakes dropping to their lowest recorded heights.

What explains the series of extreme events? Attributing any single weather event to climate change is a complicated business. Part of the difficulty reflects the intricate mechanisms of Earth’s climate, where persistent warming is the ominous background hum against which numerous other patterns play out. “Every event is a combination of climate change and climate variability,” says Caroline Wainwright, a climate scientist at Imperial College London.