in(Intergovernmental Panel on Climate Change) has calculated that with a 1.5°C increase in global global temperature by the end of the century, compared to pre-industrial levels, the frequency of episodes extreme will be multiplied by four! In the US, the heat has already become a phenomenon which kills the most in thirty years: from 1991 to 2020, the heat wave caused an average of 143 direct deaths per year, followed by floods, then , , and, finally, cold and snow. In this country more than doubled in the last 40 years.
The heat index is used to assess the risk to the human body.
Scientists use two indexes to measure heat-related discomfort and health risk:(thermal index), which combines the temperature environment and relative humidity in the shade, but also wet bulb thermometer (wet bulb temperature), less subjective and more accurate. in wet bulb thermometer characterizes the lowest temperature of an object or body that cools when moisture evaporates from it. This index simply measures our body’s ability to cool down thanks to in hot and humid weather. The idea is to determine from what level our body can no longer cool down: from this level becomes real.
Initially wet bulb thermometer measured with a simple thermometer wrapped in a damp cloth and exposed to the open air. The thermometer then recorded the temperature as the water evaporated from the laundry. Currently, this indicator is calculated using the electronic equipment of weather stations that work with satellite data. Thatuses tools located in like AIRS (Atmospheric infrared echo sounder) and ECOStress (ECOsystem Experiment with space thermal imaging radiometer). An American organization is currently developing a new SBG project (Mission Surface Biology and Geology) in order to obtain more accurate data on the process of moisture evaporation.
By 2050 some parts of the world will be too hot to survive
Scientists believe that the index wet bulb thermometer The maximum temperature a person can withstand is 35°C for six hours. Entrieshave already noted wet bulbs above 35°C many times since 2005: in the subtropics of Pakistan and the Persian Gulf. Over 40 years, the frequency of these wet bulbs extremely high has tripled. Most of the hot and humid regions of the planet have an index wet bulb thermometer usually does not exceed 25-27°C.
NASA climate prediction models try to identify countries where the index wet bulb thermometer will soon be too high to survive. This will be the case for South Asia, the Persian Gulf (Iran, Oman, Kuwait) and countries bordering the Red Sea (Egypt, Saudi Arabia, Sudan, Ethiopia, Somalia, Yemen) from 2050. East China, parts of South Asia and Brazil are also expected to regularly exceed the index wet bulb thermometer 35°C by 2070. NASA predicts the same fate for some US states in Midwest In 50 years, like in Arkansas, Missouri and Iowa. However, the researchers note that the risk of death is present even at rates below 35 ° C. Duringin the northwestern United States and western Canada (approximately 1,400 dead), wet bulb thermometer did not exceed 25°C. The index indicates a health hazard as soon as the temperature exceeds 12°C below normal. Normal body temperature is around 37°C.