Extreme precipitation to threaten 60% of world’s major cities by 2050

Los Angeles has been battered by intense rains, floods and mudslides in recent weeks. The deluge has displaced thousands across the city, causing an estimated USD11 billion in damage to infrastructure and economic losses.

The chaos brought about by the record rainfall highlights the growing threat posed to the world’s major cities by extreme weather. When looking at the 578 global cities with a population over a million, 317, home to more than a billion people, are rated high or very high risk on our baseline Extreme Precipitation Index, which measures the frequency and intensity of heavy precipitation in the current climate.

By 2050, a combination of rising global temperatures and urban population growth could see this swell to 362 cities, home to around 1.6bn people, according to our data covering an ‘intermediate’ emissions scenario. Major metropoles such as Mumbai, Manila and Medellin are among those facing the highest risk.

As shown in the chart above, extreme precipitation risks run particularly high in the developing world, where many municipal governments have inadequate policies and funds to respond to the challenges posed by heavy rainfall events amid rapid urbanisation.

Indeed, sub-Saharan Africa accounts for all 20 of the global cities set to grow fastest over the next 15 years. Of these, 17 could face high extreme precipitation risks by 2050. These include the burgeoning megacities of Dar es Salaam (Tanzania) and Kinshasa (DR Congo), set to be home to a combined 40m people by 2035.

For cities on the global frontline, intensifying rains and more frequent flooding will have a profound impact not just on human lives, but on economies too. Shuttered factories, compromised transport networks and damaged infrastructure will be felt in both local and global supply chains, as disruption drives up prices and limits the availability of goods.

As extreme weather events become more common, organisations that put environmental risk at the forefront of their strategic decision-making will be best placed to mitigate, adapt and respond to the effects of an increasingly unpredictable climate.

Jess Middleton

Data Journalist

Climate & environment

Building corporate and investor resilience to climate and environmental risks