When Zurich becomes like Milan, London like Barcelona

Scientists warn that one in five of the world’s major cities will face unprecedented climate conditions by 2050 as rising temperatures heighten the risks of drought and flooding.

A research team of the Crowther Lab at the ETH Zurich in Switzerland analysed 520 cities across the world, including urban centres with a population of more than one million residents.

Under the study scenario, European cities will warm by about 2.5 degrees Celsius across the year, but summers and winters could be 3.5°C and 4.7°C warmer respectively, according to the lead author, Jean-François Bastin.

The research showed that 77% of the cities studied will experience a striking change, many in the northern hemisphere resembling places that are over 1,000km (620 miles) further south in 30 years’ time.

As a result, London’s climate in 2050 could be similar to Barcelona’s in Spain, Seattle more like San Francisco, Tokyo more like Changsha in central China, and the future climate in Zurich similar to Milan in Italy.

Many cities, notably in poorer regions, face large and growing slum populations that lack basic services and are increasingly at risk from climate disasters, according to the study that was published in the American PLOS ONE science journal.

The scientists projected what would happen as temperatures rise another +0.5C to near the lower 1.5°C target set in the 2015 Paris Agreement on climate change.

“We definitely and very quickly need to change the way we are living on the planet. Otherwise we are just going to have more and more droughts, flooding and extreme events,” said Bastin, quoted by the Reuters news agency.