Climate forecasts in the next 30 years could look like this: Winters in the Big Apple might have the weather of today's East Coast beaches, damp and cold London may be hot and dry like Barcelona, the wet north west could be like drier San Diego, and Washington D.C. will be a lot of like today's mid-Tennessee with only an even larger variation in temperatures and precipitation. Those predictions in line with the first global analysis of how some cities' climate conditions may just shift behind global climate change.
"We wanted to know what's the most conservative estimate of what the climate will be for 520 major cities in 2050," said Tom Crowther, a researcher at ETH Zürich, and senior author of the study published in the peer-reviewed science journal PLOS ONE. "The changes we found are huge," Crowther says.
To show their findings the Crowther Crowther Lab in Switzerland created a world data map that pairs one city's future climate conditions with current ones. For instance, Minnesota in 2050 will be more like Missouri, with Minnesota's warmest month increasing from roughly 80 degrees Fahrenheit on average to more than 90 degrees Fahrenheit by 2050.
It's safe to say that cities in the Northern Hemisphere will have the climates cities more than 620 miles to their south have today, he said.
In Europe, summers and winters could get significantly hotter by 2050, with average increases of 3.5°C and 4.7°C, compared with 2000.
The shift of higher temperatures northward of 12 miles a year appears practical, as do the findings, said Michael Mann from Pennsylvania State University. Still, the conclusions seem rather "sobering" Mann stated. Another serious fact is that the probability that nearly 65 percent of the world's population are going to be living in urban areas by 2050.
"The carbon emission predictions used in the study is the extremely conservative 1.5 to 2 degrees Celsius stabilization projected by 2050. Actual carbon emissions are significantly higher and are closer to an estimation of around 3 to 4-degree Celsius. However, the temperature increase on each trajectory are exceedingly similar up until around 2050, and then the high-emission forecast we see now, diverge greatly," said Mann.
"Regions like the Middle East will only get hotter and drier, with major consequences for food production and the ability of the cities there to provide enough water and cooling," said Crowther.
For most cities the implications of the study are somewhat "horrible," he says.
The majority of the nearly 120 cities that may undergo such "novel" climate changes are in tropical climates. Places like Kuala Lumpur, Jakarta, Rangoon, and Singapore, could all be seriously effected. However, the changes in tropical cities are going to be less in terms of rising temperatures, and more on increasingly frequent, extreme precipitation events, as well as an increase in the severity and intensity of droughts.
"The fate of major tropical cities remains uncertain as many will experience unprecedented climate conditions," the study concludes.
