Heat waves are increasing across Canada-hotter nights are also dangerous


When it comes to climate change, there is a fairly easy-to-understand extreme that will affect mankind in the coming decades: high temperatures.

Scientists know that climate change will increase the frequency or intensity of events such as hurricanes, droughts, floods, and heat waves. But, especially when it comes to heat waves, it has had deadly consequences all over the world.According to a Research recently published in The Lancet, Every year more than 5 million people die from temperature-related diseases, 91% of which are related to high temperature.

Although many of these deaths have occurred in tropical countries, heat waves are beginning to affect climates further north.

During this period The heat wave from the end of June to the first week of July choked British Columbia and killed more than 800 people (as of this writing) In the province. In contrast, according to Dr. Jatinder Baidwan, Chief Medical Officer of the BC Coroner Service, 232 people died during the same period last year. The coroner’s office is continuing to investigate all deaths to determine exactly how many are related to the high temperature.

Earlier this month, a man left a community center in Toronto during a heat wave. Some cities have opened cooling centers for people who cannot use air conditioning during the heat wave. (Michael Wilson/Canadian Broadcasting Corporation)

Although we know that the temperature is rising during the day, in some areas-especially parts of Ontario and Quebec- The temperature rises faster at night.

Those warm nights mean that our bodies have no time to cool down. For example, for people with health problems such as heart disease or asthma, this can cause great problems and can be fatal.

“Our bodies are not designed to endure more than 30 degrees of environmental heat,” Baidwan said. “If you think about it, what happens to the air conditioner? When you put pressure on it, it freezes outside and then stops working. In some ways, this is a good metaphor for what happens to our body. In In extreme heat, we find it difficult to achieve the usual homeostatic mechanisms and protocols that occur in our bodies.”

Watch | How can we better prepare houses and buildings for rising temperatures?

After British Columbia experienced a record-breaking heat wave, experts weighed in on long-term and effective infrastructure solutions. 5:59

The heat waves affecting the Pacific Northwest are very unusual—according to a report, such heat waves occur every 1,000 years. Recent analysis by the World Weather Attribution Group, A group of scientists who analyze severe weather events. However, in parts of eastern Canada, including Ontario and Quebec, heat waves and tropical nights are more frequent, with night temperatures reaching 20 degrees Celsius or higher.

For example, according to Canadian Climate AtlasFrom 1976 to 2005, the number of tropical nights in Toronto averaged about 6.9 times a year. With climate change, carbon emissions are expected to rise to 17.6 times a year from 2021 to 2050 when carbon emissions are significantly reduced.

If the current carbon emission rate continues, the average number of tropical nights in Toronto from 2021 to 2050 is expected to reach 20.6 per year. From 2051 to 2080, under two different emission scenarios, the average figures will rise to 26.4 and 42.8 respectively.

In 2018, a The heatwave swept Montreal from June 29 to July 5; The average temperature during the day is about 34 degrees Celsius. The temperature at night is not lower than 20 degrees Celsius. A total of 66 people died.

Nathan Gillet, a research scientist at the Canadian Center for Environmental and Climate Change Research, said: “We have seen an increase in extreme high temperature events in Canada, which is greater than the global average warming. “Canada’s average change The warming is about twice the global average warming. And extreme high temperatures are increasing at a similar rate. Not only the hottest maximum temperature, but also the minimum temperature and night minimum temperature are increasing. “

Extensive influence on nature

The average temperature in Canada has risen by 1.7 degrees Celsius, and the rate of warming in this country is more than twice that of the earth.

Heat waves with above-average temperatures during the day and night continue to increase, causing losses to animals, fragile ecosystems, and crops.

A kind Research published in the journal Global Change Biology It was discovered in October last year that night temperatures in most parts of the world are rising. Areas where the temperature rises more at night than during the day have more cloud cover, more precipitation, and higher humidity. This may affect animals that are active at night, as well as animals that are active during the day, who use the colder temperatures at night to recover from heat stress.

You can see dead fish floating in the Pembina River in Alberta. The fish are believed to have died due to low oxygen levels in rivers and lakes caused by a heat wave in Alberta earlier this month. (Stephanie Combs/CBC)

“[The changes] Increase the limits of nocturnal species that can move. As a result, you may change in scope and then disrupt the ecosystem due to changes in competition and changes in the predator/prey relationship and things like that,” said the lead author of the study and Daniel Cow, a research assistant at the University of Exeter, UK. Said Kess. Institute of Environment and Sustainable Development.

A new set of indicators

As the climate changes, the government finds that they need a new set of indicators to measure severe high temperature events.

year 2013, Australia has added new colors to its heat map, As the temperature soared to a level they had never experienced before.

Recently, on Tuesday, The Met Office issued the first amber extreme high temperature warning as the temperature is expected to rise to more than 30 degrees In parts of the country. Compared with some areas in Canada, the daytime temperature of more than 30 degrees does not seem to be high, but it all depends on people’s habits.

In another example of how the government is trying to adapt to climate warming, a team from the National Institute of Science of Quebec (INRS) and the National Institute of Public Research of Quebec (INSPQ) announced on Wednesday, The province’s new heat wave warning threshold It should be introduced. Researchers say that the warm season in Quebec starts earlier and ends later.

As the earth continues to warm, air conditioning seems to be a possible solution. The problem is that running them requires energy, which also generates heat. The city has created a “heat island”, and the concrete structure further amplifies the heating and puts more pressure on people living in hotter climates.Some cities like Toronto with Montreal It is trying to introduce more environmentally friendly building codes and designs to solve this problem.

“[Heat waves aren’t] We think this is a big hazard in Canada, but as the climate warms, we will see this situation more and more,” said Gillette of the Canadian Ministry of Environment and Climate Change. danger. Yes, this is… We will see more and more things in Canada. “





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