Climate in most major cities to change by 2050

By the year 2050, a fifth of the world's cities will experience unprecedented climate conditions and environments that currently don't exist in any major metropolis, according to new research.

A team of scientists at the Crowther Lab in Switzerland produced the report, Understanding Climate Change from a Global Analysis of City Analogues, which projected the climate for 520 major cities 30 years in the future.

The results showed that 77 percent of the world's cities will experience a striking change in climate conditions by 2050, and 22 percent of the 520 cities will see conditions that are not currently experienced by any existing major cities.

In China in 2050, the climate of the city of Xi'an, in Shaanxi province, home of the Terracotta Warriors, will be similar to that of current day Maseru, the capital city of Lesotho in southern Africa, with the maximum temperature of the warmest month likely to increase by 4.5 C.

Chongqing in southwest China will resemble the climate of Swaziland capital Mbabane, as the warmest temperature is predicted to rise by 5.1 C.

Scientists predict summers in Europe will get warmer by an average of 3.5 C and European winters will see temperature rises of 4.7 C.

London's climate will be more similar to Barcelona, and Madrid's to Marrakech.

The Crowther Lab hopes the analysis and mapping will motivate and equip decision-makers in taking necessary steps to prevent or address some of the climate impacts due to the threat of climate change.

"Generating an understanding of the shifts in climate conditions of the world's cities is critical if we are to get a global unifying perspective of the impacts of climate change," said Jean-Francois Bastin, lead author of the research paper. "With this analysis from Crowther Lab scientists, we want to help people visualize the impact of climate change in their own city, within their lifetime."

The report also found that cities in tropical regions will experience smaller changes in average temperature but will be dominated by shifts in rainfall regimes. This may lead to a noticeable increase in precipitation events, and the severity and intensity of droughts.

"Across all scientific fields, the greatest challenge in climate science is no longer the precise measurement of climate change impacts, but inspiring people to visualize its tangible effects in order to motivate action," said Tom Crowther, senior scientist and founder of the Crowther Lab.