Adelaide, in southern Australia, reached 46.6º of temperature last week. Never before since there are records, this city had been so hot. Meanwhile, last Wednesday, the city of Chicago (USA) It was colder than ever: -27º, which touched the -50 in wind chill due to the cold wind. The US weather service came to recommend not breathing too much if it was on the street. Between both cities there are 16,000 kilometers away and one is in the middle of summer and the other in the worst of winter. However, both phenomena could have a common link: climate change, which is increasing the frequency and intensity of extreme weather events.
Australia, particularly the southern regions, have a climate as Mediterranean as that of Spain. That is why it is not uncommon for them to have their own heat waves during the austral summer, with their episodes of drought and fires. But this year all the records are being broken. In Port August, about 300 kilometers from Adelaide, they marked the highest minimum in the history of the country, with 24.6º. But further north, temperate New Zealand is also going through a lot of heat. With a climate reminiscent of the British Isles, in several cities of the southern island have touched the 35th for several days.
Meanwhile, in most of Canada and the central region of the United States they are suffering from very cold air from the Arctic in an occasional phenomenon called polar vortex. Under normal conditions, this large area of low pressure and extremely cold air rotates on the polar circle, with strong counterclockwise winds that hold the cold around the pole. However, occasionally, the intrusion of hot air masses from the south can interfere with this process, such as breaking the circuit and spreading cold from the south.
Although there is no obvious connection between the two events, recent studies have indicated that, as the planet warms, the climate is becoming more extreme. A report by the European Council of Academies of Science, published last year, showed how heat waves and droughts had multiplied by almost 40% since 1980, with a somewhat lower percentage in cold waves. These figures, according to their estimates, could triple by the end of the century.