The study of climatologists from Princeton University (Princeton University, USA) was published today at a reviewed magazine Nature Geoscience. Isaac Held (ISAAC HELD), and Zhang (Yi Zhang) and Stephan Fueglistaler combined data of 22 climatic models. Scientists analyzed how fast in the tropics the temperature of the wet thermometer (Wet-Bulb Temperature, TW) will reach the mark of 35 degrees Celsius.
This indicator is extremely important for human survival for the following reasons. The fact is that the main way of natural cooling of your body for people is evaporation. We sweat, this process takes part of the heat and allows you to maintain a normal temperature for the life of the body. However, the effectiveness of evaporative cooling is inversely proportional to air humidity.
That is, at high temperature and humidity, which is characteristic of tropical regions, the adaptation limits of the human body will be achieved faster. A critical value with 100% humidity is considered to be 35 ° C - heightens the skin above this temperature does not have time to lose heat. Even if a person has an unlimited supply of drinking water, such conditions for a long time without consequences for the body cannot survive. Such conclusions came American physiologists for ten years ago.
To determine the temperature, taking into account humidity, the measurement of a wet thermometer is used - that is, covered with water-swammed tissue. Such a method allows us to estimate the difference between an open thermometer and cooled water evaporation in specific conditions. And accordingly, and evaluate the human ability to safely be in them. As I installed the chzan with colleagues, already with an increase in average annual temperatures by 1.5 degrees Celsius, in the regions between 20 degrees of northern and 20 degrees of southern latitude, TW for more than three hours a day will reach 35 °.
With the most pessimistic forecasts, a considerable part of the population of the Earth will be in the constant danger of hyperthermia, especially considering that the country located in the tropics shows the greatest demographic growth. And if at first it will only affect people's performance, then in the future, chronic overheating will literally lead to deaths. In the long run, thermal strikes, especially frequent, threaten serious violations of the activities of cardiovascular, nervous and respiratory systems of the body.
However, not everything is so bad, it is only one of the models. In addition, the earthly biosphere passed through similar warming. Earlier and large animals were inhabited in the tropics, for example, during the last interdiction (Mikulinsky) about 130-115 thousand years ago. But it should not relax, such a strong increase in the temperature of the wet degrees, at a minimum, will seriously increase the need for energy for tropical regions - air conditioners will be vital in the economy.
Source: Naked Science