San Francisco could be as hot as Portugal and New York would feel like Virginia Beach by 2050 if the findings of a major new climate change study are correct.
Researchers from thinktank The Crowther Lab assessed how 520 cities around the world would look by 2050 in an "optimistic scenario," where the implementation of policies will have stabilized CO2 emissions and the mean global temperature will have increased by 1.4 degrees Celsius.
In the U.S., Washington, D.C. would have a climate like modern-day Nashville by 2050, the analysis found, while San Francisco's climate will be more like the current climate in Portuguese capital Lisbon. New York City's climate would be up to 4 degrees warmer in 2050, resembling Virginia Beach as it is today, and Seattle will be closer to San Francisco in 2019.
London's climate would be more akin to Barcelona today, the report predicted, while Madrid's will be closer to modern-day Marrakech.
The analysis showed that more than three-quarters of cities around the world will experience "a striking change of climate conditions," even in the optimistic scenario. Researchers claimed that one in five cities – including Kuala Lumpur, Jakarta, and Singapore – are likely to exist in a climatic conditions that don't currently exist on the planet today, with wild swings between drought and heavy rainfall.
Although tropical regions will experience smaller changes in temperature, their wettest months will become 5% wetter and their driest months 14% drier, according to the analysis. Droughts in the region will become more severe, the report claimed.
The most dramatic shift is predicted for cities with northern latitudes, which would see their climates in 2050 resembling the current conditions in cities more than 600 miles to their south.
In Europe, cities were expected to be 3.5 degrees warmer in summer and 4.7 degrees warmer in winter by 2050.
"If carbon emissions remain unabated … the costs of climate change under a business as usual scenario will exceed $12 trillion by 2050," the report's authors said. "We believe that it is through this comparison with current cities and their known struggles with their climate conditions that the need to act becomes tangible."
Climate change has been flagged as an urgent issue that poses a social and economic threat.
The UN warns that without action, the world's average surface temperature is likely to surpass 3 degrees Celsius this century.
Earlier this year, a World Economic Forum survey identified extreme weather events and the failure to mitigate climate change as two of the biggest global risks.
Meanwhile, IMF chief and nominee for the European Central Bank presidency Christine Lagarde previously warned: "If we don't do anything about climate change now, in 50 years' time we will be toasted, roasted and grilled."