WITHIN just over 30 years, the climate in Madrid will be similar to what it is in Marrakech today and that of London will be very much like Barcelona's is now, according to research at the Federal Polytechnic School (ETH) in Zürich, Switzerland.
Published in the science magazine Plos One, the investigation concludes that 77% of major cities worldwide will have a very different climate in the year 2050 to that of 2019 – in fact, most of those in the northern hemisphere will feel more like those 1,000 kilometres south, and those in the southern hemisphere will feel like those 1,000 further north.
Londoners could be basking in months of summer warmth such as that seen in Spain's second-largest city in the north-east, cooling down considerably by mid-October but still not needing a coat for nearly another month.
In Madrid, sweltering summers like those of the southern Moroccan city of Marrakech may not be noticed much for their rise in temperature, given that the Spanish capital is always baking from June to early September, but the humidity may be greater, and the warm weather start earlier and finish later, with daytime temperatures in November of around 23ºC to 25ºC and no heating or covers needed at night.
The research also shows the climate in Stockholm, Sweden – currently similar to that of Scotland – will be closer to that of Budapest, Hungary, which is roughly that of mid-France, whilst Moscow, with its punishingly-cold winters in double figures below zero will feel more like that of Sofia, Bulgaria, which is slightly warmer than the mildest year-round temperatures in middle England.
Basing their investigation on 520 of the world's largest cities, the research team in Switzerland found that over three-quarters of metropolitan areas will have a temperature and humidity level of those 1,000 kilometres closer to the tropics.
The remaining 23% of cities – all of which are the closest to the equator - will not see much change in temperature but will have much longer droughts and rainy seasons.
In fact, 22% of the world's cities will have a climate régime 'which does not exist anywhere on the planet today' by the year 2050, rising to 30% of those closest to the equator, which will generally be drier.
These figures are based upon 'the most optimistic scenarios', say scientists.
The study is aimed at helping town planners and other authorities prepare their cities for the future – for example, new buildings in the south of England and central and northern Europe may need to be fitted with air-conditioning and designed so the sun can be filtered out in summer, and other infrastructure like public outdoor swimming pools may be required.
Global warming in the last few thousand years has already made a big difference to temperatures and also changes the face of crops and wildlife native to various countries – Spain's northern region of Cantabria, for example, until about 12,000 years ago, had a climate similar to that of the north of Scotland.
