Researchers from Zürich Technical University analyzed the climate in 520 cities using the so-called RCP 4.5 scenario which assumes a significant reduction in emissions, although not as significant as required by the Paris Agreement.
They found that 77 percent of the world's cities will see a drastically changed climate over the next 30 years, according to the study published in scientific journal Plos One.
That means cities in the northern hemisphere will by 2050 see a climate similar to the current climate of cities more than 1,000 kilometres further south.
To illustrate the findings, the Crowther Lab in Switzerland created an interactive map that pairs one city’s future climate conditions with current ones.
The map shows London becoming as warm as today's Barcelona, Stockholm as warm as Budapest, Paris as warm as Canberra – and Copenhagen as warm as Paris.
The maximum temperature of the warmest month in Denmark’s capital is likely to increase by 5° Celsius. That will result in a mean annual temperature change of 2° C, according to the study.
In the tropics, temperature differences won't be as great as elsewhere. However, the climate crisis is more likely to be reflected in droughts and extreme precipitation. The researchers cannot predict exactly what this will mean for these cities.
They also found that megacities such as Jakarta, Singapore and Kuala Lumpur are probably facing far-reaching changes.
“The point of this paper is to try to allow everyone to get a better grasp on what's happening with climate change,” lead author Jean-François Bastin said to AFP.
Bastin, who is from Belgium, told the news agency it was not certain that by 2060 his country would experience sub-zero temperatures in winter, a necessary condition for wheat seeds to become activated.
As summer temperatures surge, more people in northern Europe will purchase air conditioners, adding to the strain on electric grids and potentially creating a vicious cycle, he added.
But straight comparisons between cites do not tell the full picture of climate change, said Markku Rummukainen, a climate researcher with Swedish meteorological agency SMHI.
“Comparisons can give a sense of what changes to the climate mean. But at the same time, you should keep in mind that the changes are more complex than just the temperature. If you just think that Stockholm is getting a Budapest climate, you might think 'that doesn't sound so awful'. But in reality the problem is much more serious,” Rummukainen told Swedish news wire TT.
“When you get changes in climate, this can have effects on the buoyancy of the ground for example, flood risk and water resources, which can lead to further problems,” he added.