Media reports of heatwaves hitting the northern hemisphere were clear: Simultaneous record temperatures “pushed the limits of human survival.” Perhaps more worryingly, “The UK could be unbearably hot in thirty years”, which would undoubtedly worry 97% of humanity living in areas with hotter summers than the UK.
The good news: Brits won’t have to move to Sweden until 2050. The bad news: The deadly heat is here, it’s getting worse, and it could soon become a much bigger problem in almost every part of the world than it is now.
Heat is a silent killer, causing more deaths than any other natural disaster: several severe heatwaves have claimed the lives of tens of thousands in Europe in recent years, including last summer. The number of deaths in developing countries is underestimated and likely much higher. But worse is coming and we must prepare for it.
The average temperature of the Earth’s surface has reached its highest level since the beginning of measurements and possibly until the last ice age. Recent heatwaves show clear signs of global warming rather than other effects of climate change, such as floods or droughts. And global warming will continue, at least until it reaches net zero. There is a fundamental limit to the body’s ability to cope with difficulties: It is an unshakable goalpost.
A 2010 study found that a “wet-bulb” temperature of 35°C or higher would make it impossible for humans to consume metabolic heat because of our constant body temperature. He suggested that this was the effective limit to survival.
The wet bulb temperature measures its ability to cool by evaporation; If the relative humidity is 100 percent it is equal to the normal temperature, otherwise it is lower. 35°C is an extreme temperature; Wet thermometers above 30°C are never seen in most places around the world.
However, sufficient global warming can push heat waves above 35°C in many regions. This overturned the common assumption that people could adapt to any amount of increased heat, meaning that goalposts could move. This will not be a goal post.
Wet bulb temperature is used by meteorologists and climatologists to measure heat stress. This is a combination of heat and humidity: high wet bulbs can occur at low temperatures in humid locations and extremely high temperatures in dry locations. New research is starting to pave the way to 35°C.
A study conducted in the USA last year found that young, healthy subjects exposed to very hot conditions begin to experience hyperthermia (inability to regulate body temperature) at temperatures close to or below 32°C, well below the wet bulb temperature of 35°C. This is an important reminder that 35°C is a theoretical upper limit, not a practical one. On the other hand, if they had done the research in India or Brazil, they would certainly have shown a higher tolerance, because over time (up to a point) the physiology adapts to heat.
The UK has a long way to go before temperatures reach 32°C and it may take some time to acclimate. Today, wet-bulb temperatures above 32°C in the coastal regions of the Middle East are very rare and short-lived, but will become more common as the weather warms up. The heat will force us to change our lifestyle, for example, to postpone or simply cancel outdoor activities in the summer months.
Strong temperatures can already prevent people from traveling to Europe or other countries in the summer.
Researchers at the University of Sydney are developing a heat warning system similar to the one in the US and conducting impact studies. It looks like we’ll soon have a clearer picture of the direct effects of extreme heat on physiology. It is still difficult to quantify or estimate the total cost of extreme heat to society in terms of health, work and quality of life.
To do this, climate and health researchers need to develop models that take into account human behavior and adaptation, as well as knowledge of physiology, weather and climate. We also need to understand what will happen to nature and look for ways to protect wildlife. Above all, we need to reach net zero carbon as soon as possible to stop the continued rise in heat. Source
Source: Port Altele
