[ad_1]
for study Published in Nature Climate Change in 2017, Mora and her team analyzed hundreds of extreme heat events around the world to determine which combinations of heat and humidity could be deadly and where those conditions might occur in the future.
They found that while nearly 30% of the world’s population today is exposed to a deadly combination of heat and humidity for at least 20 days each year, that rate will nearly halve by 2100, even with the sharpest reductions in greenhouse gasses. emissions.
Other researchers have found that climate change creates extreme heat waves up to hundreds of times. probably and cause more than a third heat-related deaths. We are changing our planet – what is the limit of what we can endure?
cool down
As warm-blooded mammals, humans have a constant body temperature of around 37°C. And our bodies are designed to operate at almost that temperature, so there is a constant balance between heat loss and heat gain.
Problems start when our bodies can’t lose heat fast enough (or not very quickly in the cold), but for now, let’s focus on heat. When your core temperature gets too hot, everything from organs to enzymes can shut down. Extreme heat can lead to major kidney and heart problems and even brain damage, she says. Liz HannaA former public health researcher working on temperature extremes at the Australian National University, Dr.
Your body often works to maintain core temperature in hot environments using one powerful tool: sweat. The sweat you produce evaporates into the air, absorbing the heat from your skin and cooling you.
Humidity interferes with this cooling method – if the air is so humid, there is already a lot of water vapor in the air, then sweat cannot evaporate as quickly and sweating will not cool you that much.
Extreme heat can lead to major kidney and heart problems and even brain damage.
Researchers like Mora and her team often use measurements such as the heat index or wet bulb temperature to assess how extreme heat and humidity interact. In this way, they can identify uninhabitable situations by focusing on a single number.
The heat index is an estimate you’ve probably seen in weather reports; influences both heat and humidity to represent how the air feels. Wet bulb temperature is literally what a thermometer measures when a wet cloth is wrapped around it. (The temperature in the estimates is technically the dry-bulb temperature, as it is measured with a dry-bulb.) Wet-bulb temperature can predict what your skin temperature will be if you sweat constantly, so it’s often used to predict how people will be. charge in extreme heat.
A wet bulb temperature of around 35 °C or 95 °F is almost the absolute limit of human tolerance, he says. Zach Schlader, a physiologist at Indiana University Bloomington. Above that, your body cannot lose heat efficiently to the environment to maintain its core temperature. That doesn’t mean the heat will kill you right away, but if you don’t cool down quickly, brain and organ damage will begin.
conditions It varies greatly, which can lead to a wet bulb temperature of 95°F. Without wind and sunny skies, a 50% humid area will reach an uninhabitable wet-bulb temperature of around 109°F, while in mostly dry weather temperatures must exceed 130°F to reach this limit.
[ad_2]
Source link