Why are Canada, US alarmingly warm?

The dangers and after-effects of global warming are manifesting themselves with increasing frequency, more intensity and longer duration all over the world. The 49.6°C recorded in Lytton,  British Columbia this month, was five degrees hotter than Canada’s earlier highest temperature of 84 years ago. A report by SHVETA MISHRA

In a report released on July 7, 2021, an international team of 27 climate scientists with the World Weather Attribution Collaboration determined that the heat wave was 150 times more likely to occur as a result of climate change brought about by greenhouse gas emissions. Parts of US and Canada which are reeling under a heat wave have reportedly been affected by the heat dome that was formed due to the cocktail of high atmospheric pressure, climate change and drought. People in cities like Seattle, Portland, Vancouver and Surrey find that the mercury has soared to breach the sizzling 46-degree mark.

The 49.6°C recorded in Lytton, British Columbia, was five degrees hotter than Canada’s earlier highest temperature of 84 years ago. The region has registered a sudden spike in deaths and it is being related to the roasting conditions and hyperthermia caused by the immense heat wave. The study finds that the record-breaking June heat wave that struck parts of the U.S. and Canada would have been “virtually impossible” without human-induced climate change, new analysis has shown. The report of the international team of 27 climate scientists with the World Weather Attribution Collaboration finds that the heat wave was 150 times more likely to occur as a result of climate change brought about by greenhouse gas emissions.

Parts of the Pacific Northwest in the U.S. and Canada experienced temperatures that broke previous records by several degrees: the small town of Lytton broke the Canadian record when temperatures reached 49.6 degrees Celsius (121.3 degrees Fahrenheit) on June 29, almost 5 degrees Celsius higher than the previous record of 45 degrees (113 Fahrenheit). Shortly afterward, most of the town was destroyed by a wildfire.

The heatwave in Portland, Oregon broke temperature records on three consecutive days, from June 26 to 28, eventually reaching 46.6 degrees Celsius (116 degrees Fahrenheit). The northwestern part of North America, among the most temperate zones in the world, broke all records on June 27 and 28, 2021 when it sizzled under an unprecedented heat wave, in yet another instance of the global climate crisis.

The Canadian province of British

Columbia and the states of Oregon and Washington in the United States Pacific Northwest are experiencing once-in-a-millennium or even once-in-10,000 years temperatures, according to reports. Record-keeping of temperatures in this region began in the 1800s. The city of Lytton in British Columbia, some 250 kilometres north-east of Vancouver, recorded a temperature of 46.6 degrees Celsius in June 27, breaking an 84-year-old record. A day later, it recorded 47.5°C, the hottest temperature that has ever been recorded in Canada. Lytton on June 28 was hotter than Abu Dhabi, according to weather experts.

Across the border, Seattle, Washington and Portland, Oregon also broke records. Seattle recorded 40°C June 27. It recorded 41.1°C June 28. For three days (June 26, 27 and 28), Portland recorded a temperature of 46.1°C.

Preliminary figures for excess deaths caused by the heat waves run into the hundreds both in the U.S. and in Canada, while the eventual death tolls, which could take several months to establish, could be much higher.

The experts say, “While we expect heat waves to become more frequent and intense, it was unexpected to see such levels of heat in this region. It raises serious questions whether we really understand how climate change is making heat waves hotter and more deadly.”

The heat wave also proved deadly for non-human populations, with a UBC researcher estimating that more than a billion coastal animals such as sea starts and clams were killed by the devastating temperatures. It has now been confirmed that last month was the hottest June in North American history. Europe, meanwhile, recorded its second-hottest June on record.

The researchers said the heat wave sent a clear warning that such extreme temperatures can now occur as far north as 50 degrees of latitude, “a range that includes all of the contiguous U.S., France, parts of Germany, China and Japan.”

The researchers behind the attribution analysis proposed two possible sources for the record temperatures, both of which are affected by climate change. The first, they said, is that the heat wave was “the statistical equivalent of really bad luck, albeit aggravated by climate change.”

The second possibility is that climate change has “substantially increased the probability of such extreme heat, much beyond the gradual increase in heat extremes that has been observed up to now”— in other words, that climate change has caused a sudden, possibly permanent upward shift in the likelihood of such heat waves occurring. This second possibility, the researchers currently believe, is less likely than the first, but will require further investigation.

The researchers calculated that, in either event, the heat wave was about 2 degrees Celsius hotter than it would have been at the beginning of the industrial revolution, when average temperatures were 1.2 degrees Celsius (2.16 degrees Fahrenheit) cooler than they are now. With further, moderate global warming of 2 degrees Celsius (3.6 Fahrenheit), which could occur as soon as the 2040s, the same heat wave would be an additional degree hotter. The researchers further determined that 2 degrees Celsius of warming could induce such heat waves to occur every 5 to 10 years.

“What we are seeing is unprecedented. You’re not supposed to break records by 4 or 5 degrees Celsius,” said a researcher from the Environmental Change Institute at the University of Oxford. “This is such an exceptional event that we can’t rule out the possibility that we’re experiencing heat extremes today that we only expected to come at higher levels of global warming.” “This event should be a big warning,” said Dim Coumou of the Institute for Environmental Studies, Royal Netherlands Meteorological Institute. “Currently we do not understand the mechanisms well that led to such exceptionally high temperatures. We may have crossed a threshold in the climate system where a small amount of additional global warming causes a faster rise in extreme temperatures.”

Regarding what should be done about such severe heat waves, the authors of the study said affected areas would need to implement heat action plans, and that early warning systems should be improved to help protect vulnerable groups.

In addition, they said, countries would need to implement longer-term plans, “to modify our built environments to be more adequate for the hotter climate that we already experience today and the additional warming that we expect in future.” They added that current goals to cut emissions by reducing use of fossil fuels “should take into account the increasing risks associated with unprecedented climate conditions if warming would be allowed to continue.”