Everything is getting hotter. We naturally mean the climate on earth. The trend is very clear. According to calculations, the climate should become unbearable for humans by the end of the century. Especially in some regions. In reality, however, this is already happening, as a team of researchers has confirmed. The heat is fatal to humans and will occur in more and more places.
Over time, more and more heat
A team of researchers from the United States and Great Britain checked the current data. They compared data from weather stations around the world. So they knew what happened to the frequency of wet temperatures (or wet light bulbs) of more than 27 to 35 degrees. It has doubled since 1979. The wet bulb temperature is a measure of warmth and moisture. It is recorded with a thermometer covered with a cloth soaked in water. And 35 degrees humid temperature are the limit that a human body can support. The study was just published in Science Advances.
Humans have an effective cooling mechanism. When the temperature rises, beads of sweat seep out of our pores and evaporate. Energy is released and the skin cools down. But the body can no longer cool down with sweat above 35 degrees. Lower levels can be fatal. Thousands died in the heat wave that hit Europe in 2003. And the humid temperature did not exceed 28 degrees.
It is known where this frequency increases. Persian Gulf, India, Pakistan and Southwest North America. "Exceeding these thresholds is very risky," says Tom Matthews. He is one of the study participants. We are generally approaching this 35 degree threshold.
This human survival limit has been briefly exceeded in the past 40 years. It is disturbing to see how this happens under our own nose.
The future that awaits us
Matthews warns that this is just the beginning. Extreme heat will very quickly hit more parts of Pakistan and India. Millions of people would not be able to adapt. And even if they could, it would require large amounts of energy to cool. That would further exacerbate the dramatic weather situation. "We are closer than we thought to cross this line drawn in the sand."
Colin Raymond of NASA's Jet Propulsion Laboratory is the first signer of the article. He says that this limit is "essential knowledge for us as a species".
Together with his colleagues, Raymond received data from 4,576 weather stations across the planet. He looked for possible cases of extreme temperatures from 1979 to 2017. The pattern was very clear. Extreme wet bulb temperatures have already occurred, especially along the subtropical coasts. There the warm and humid air of the ocean meets the hot air of the country.
If carbon emissions are not dramatically and immediately reduced, these extreme cases will become more common. They will spread to ever larger areas of the planet. They are unbearable conditions for people without technologies like air conditioning. Any activity or work outdoors would be almost impossible, because when the heat reaches deadly levels, no one can go out.
"We need to rethink how we should live in places where there are conditions beyond what we have developed to endure." So Raymond thinks. "Life in the Persian Gulf in summer can be like life at the South Pole in winter."