10/14/2021 at 7:00 p.m. CEST
In the Canadian region of British Columbia, 260 kilometers northeast of the city of Vancouver, the town of Lytton has settled.
Founded in the mid-19th century by gold diggers, this area was originally home to the Ntlakyapamick Indian tribe, which thrived for centuries adapting very well to the cold environment of the place.
They were skilled salmon fishers, hunters, gatherers, and herders, as low temperatures limited their agriculture to a few species capable of growing during the few balmy summer months.
Surprisingly, on the last Sunday in June of this year, an unusual heat wave broke out in Lytton, reaching the highest temperature on record in all of Canada: 49.6 degrees Celsius.
The worst part was that these maxims were held for days. Many people began to suffer from heat stroke and the area was evicted.
From heat to fire
It was totally unthinkable in a place so far north. But the problems were just beginning.
On the third day of the heatwave, strong winds hit the region. Then a terrible forest fire broke out. Barely 15 minutes after its outbreak, the fire spread at a speed never seen before. Over 90% of the town of Lytton has been totally destroyed.
The case of Lytton (located at a latitude of 50º 13.5’N) is a surprising example of how global warming is affecting with disastrous consequences places which are still much further north than the northernmost point of the country. ‘Spain (Estaca de Bares at a latitude of 43º 47.2’N).
Global warming affects us all, even rich first world countries like Canada. And that the American continent is today one of the places least affected by this warming.
But what’s even worse is that global warming is destroying large areas of resource-poor countries, like those in the Sahel, which were not responsible for the massive release of greenhouse gases.
There is the paradox that many countries barely responsible for global warming are the most affected by its consequences.
It is a public health problem
The essence of the problem is that we believe that global warming is an environmental problem. And the degradation of the environment worries us a little because it seems to us something ethereal, difficult to specify.
But we are wrong. Global warming is first and foremost an extremely serious public health problem. More precisely one of the biggest.
And we must not wait.
During this century, heat stress has killed more than 5 million people a year worldwide.
So far this century, extreme temperatures have killed 20 times more people than Covid-19. And the number of heat deaths increases dramatically over time.
The danger of heat stress
The large number of deaths caused by heat stress has led hundreds of scientists to work under the coordination of the International Society of Biometeorology to create the Universal Thermal Climate Index (UTCI).
And by using the most advanced thermophysiological model (the UTCI-Fiala model), researchers can assess with tremendous precision the heat stress that humans experience based on meteorological parameters such as temperature, humidity, wind, or weather. radiation.
The results obtained are much more worrying than previously thought.
To get an idea of the real risk we run from heat stress, it’s worth getting into the numbers. To simplify, we will limit ourselves to analyzing the 3 most important parameters: temperature, humidity and exposure time.
Below 27ºC degrees and with less than 80% relative humidity we are in ideal conditions for health, but only when exceeding 30ºC in conditions of high relative humidity, or 34ºC in the driest environments, we are already starting to experience dangerous heat stress.
Heat stress has acute, short-term effects that can kill us or send us to intensive care only after a few hours of exposure to high temperatures, depending on environmental conditions and our physical condition.
Data that pushes us to the limit
After analyzing hundreds of fatal heat episodes affecting millions of people, prolonged exposures above 50 ° C with very low humidity are known to be fatal even for young and healthy people.
Periods of about 3 days under these conditions are fatal for the vast majority of people.
But as age increases, or there are factors that degrade health, or for young children, death occurs after much lower exposures of just a few hours.
The biggest problem occurs in conditions of high relative humidity. Thus, the temperature that we can endure before dying from heat stress is much lower.
For example, temperatures as low as 32 ° C with 100% relative humidity put the healthy person at risk of extreme death after exposures as short as 6 hours.
Very rigorous studies on millions of cases have revealed the recipe for not putting yourself in danger of death by heat:
Always avoid environmental conditions above 30 ° C with 100% relative humidity 35 ° C with more than 80% humidity 40 ° with more than 50% humidity 45 ° C with more than 20% humidity
Although we don’t know it, in many places in Spain the environmental conditions exceed these values several times a year, subjecting us to heat stress conditions that put our lives in danger.
Climate refugees fleeing the heat
Today, just over 12% of the earth’s surface is uninhabitable due to extreme heat.
But the area that global warming makes uninhabitable is increasing dramatically year after year.
It is estimated that by the end of the century, even if we can immediately limit CO2 emissions, 18% of the Earth will be uninhabitable due to the extreme heat.
But it is almost impossible for us to be able to limit our greenhouse gas emissions into the atmosphere in the short term.
And to continue with the current rate, by the year 2100, about a quarter of the Earth’s surface will be uninhabitable because of the heat.
Large areas of our country will fall into this category.
By then, the biggest waves of migrants will occur, who will be climate refugees fleeing the deadly heat instead of people who aspire to lead better lives.
It’s already shortening life in too many areas
But we don’t even have to go into such extreme situations for heat stress, while it doesn’t kill us immediately, dramatically shortens our life expectancy.
In that sense, the results are impressive. Living in hot areas with high humidity reduces life expectancy up to more than 15 years.
Although we don’t realize it, we start to experience heat stress above 30 ° C.
Children under 5, people over 60 and the chronically ill are extremely vulnerable to this stress.
In most of our country, conditions that produce severe heat stress and could even kill us are largely overcome for many days of the year.
Unfortunately, we are still very little aware of such a danger.
We must be aware of the serious risks to our health. In Europe, many young children have already died from heat stress.
Let us not forget that the release of greenhouse gases into the atmosphere is not only an environmental problem. It is above all one of the greatest known risks to public health.