The extreme heat caused Lytton in Canada to reach 50C
(Rinnovabili.it) – Theextreme heat wave which swept the Pacific North West in June 2021 and rewrote all era temperature records virtually impossible without man-made global warming. Not only that of 150 years ago, the second half of the 19th century, that is the period that climate science takes as a basic reference for the pre-industrial era. Even in the climate of the 1950s, an event like the one that roasted Canada and the United States for days was technically impossible. In today’s climate the frequency of such a wave is Once every 200 years. But it will grow in the future, and even in a scenario of moderate emissions cuts (with warming of 2°C), events of that magnitude they could recur every 10 years as early as 2050.
This is the conclusion reached by a study carried out by the Lamont-Doherty Earth Observatory of Columbia University e published in Nature Climate Change. Study that reanalyzes the data relating to the extreme heat that marked the all-time record for Canada with 49.6°C in Lytton and over 40°C in Seattle, Portland and other west coast cities. And it sheds light on the specific role of the different factors behind the event, thus determining more precisely the chances of it happening again in the future.
“It was so extreme that it was tempting to apply the ‘black swan’ label, an event that cannot be predicted”he comments Samuel BartusekPhD student at the Lamont-Doherty Earth Observatory and first author of the paper. “But there is a line between the totally unpredictable, the plausible and the totally expected that is difficult to classify. I would call it more of a gray swan”.
With some approximation, the study argues that two-thirds of the power of the extreme heat wave comes from an overlap of factors directly linked to climate change, including generally higher temperatures and drier soils. The remainder depends on more economic phenomena, which caused the extreme heat bubble to remain in the area for days on end. However, even these factors, defined as non-linear, are probably influenced to some extent by the climate crisis.