Most of the areas of India are suffering from severe heat and the workers working in the open sky are in the worst condition. When the mercury reaches near 40 degrees Celsius, panic starts. But do you know that only 32 degrees Celsius can be fatal?
To understand this, it becomes important for you to know about the nature of temperature that most of us have never heard of. This form of this heat is the wet-bulb temperature.
Heat and humidity are measured by the weight bulb temperature. Even completely healthy people who are used to living in heat are not able to work at 32 °C wet bulb temperature (TW) and even if such people sit in the shade at 35 °C TW, they die within 6 hours. Will happen. Climate change continues to increase the risk of these wet bulb temperatures. On this link you can see the wet bulb temperature of all the cities of India .
A briefing has been prepared by Climate Trends to explain this topic, in which some important things have been told which are as follows .
how heat affects the human body
Heat stroke can cause symptoms ranging from dizziness and nausea to swelling of the limbs , restlessness , unconsciousness and death. Exposure to heat activates 5 physiological mechanisms :
These systems affect seven vital organs (brain , heart , intestines , kidneys , liver , lungs and pancreas). There are 27 deadly combinations of these systems and organs which are said to be caused by heat.
How summer affects India’s productivity
Scientists have ranked India as a country at high risk in terms of labor productivity during the hottest months , when the WBGT is between 30 and 33 degrees Celsius . According to an estimate, due to extreme heat and humidity in India, there is a loss of 21% in working hours outside the homes . RCP 8.5 under 2030 anticipates it had risen to 24% and by 2050 to 30%.
In the current year, the deadly combination of extreme heat and humidity in most parts of India results in loss of labor productivity for 12 to 66 days every year . Somewhere in the world, this combination proves to be fatal, but it is not necessary to be so in India. Hotspots adjacent to the eastern coastal areas of India i.e. 124 days in Kolkata, 171 days in Sunderbans, 178 days in Cuttack , 173 days in Brahmapur , 113 days in Thiruvananthapuram , 140 days in Chennai , 47 days in Mumbai and 63 days in New Delhi They fall prey to this horrific combination.
Estimated increase in the number of days of wet bulb temperature under different emission conditions
In RCP 8.5 – Number of wet bulb temperature days till the year 2050 in Kolkata 176 days , 215 days in Sundarbans , 226 days in Cuttack , 233 days in Brahmapur , Thiruvananthapuram 314 days , Chennai 229 days , Mumbai 171 days And in New Delhi it will be for about 99 days.
Under RCP 8.5 – by the year 2100 , the number of such days in Kolkata will increase to 221 . At the same time , there will be 253 in Sunderbans , 282 in Cuttack, 285 in Brahmapur, 365 in Thiruvananthapuram , 309 in Chennai , 261 in Mumbai and 131 in New Delhi . West Coast will be more affected due to wet bulb temperature , which includes 269 days in Goa (currently 35 days) , Kochi 362 days (currently 98 days) and Bangalore 349 days (currently 72 days). Bulbs will succumb to temperature.
In RCP 2.6 conditions – till the year 2100 in Kolkata 157 days , Sunderbans 193 days , Cuttack 216 days , Brahmapur 218 days , Thiruvananthapuram 240, Chennai 179, Mumbai 112, New Delhi 81, Goa 94, 163 days in Bengaluru and 206 days in Kochi .
Wet Bulb and Wet Bulb Globe Temperature:
In summer, the human body cools itself through sweat, but if the humidity level becomes too high, sweating does not work and the risk of dangerous overheating arises. Wet bulb temperature (DW) is a measure of heat and humidity, and thus is useful in predicting whether weather conditions are safe for humans. It is measured by wrapping a wet cloth around the bulb of the thermometer and represents the minimum temperature you can lower through evaporation (such as sweating) from the water. TW is equal to dry bulb temperature under 100% humidity. At the same time , these temperatures can be very different in conditions of low humidity .
Other methods of measuring heat and humidity include Wet Bulb Globe Temperature and Heat Index Wet Bulb Globe Temperature WBGT includes TW but uses additional globe thermometers to measure solar radiation and wind speed . WBGT is often used for outdoor exercisers such as soldiers or athletes. However, it can also be used inside buildings assuming there is no solar radiation or air interference, or it can be done using the simplified WBGT ( 0.7 TW + 0.3 globe temperature). WBGT usually But a few degrees less than TW.
Some governments use the heat index to prepare a severe heat wave warning. The Heat Index (HI) is the combination of the air temperature and the relative humidity in the shade. Just like in TW, it does n’t always use the air temperature in the shade.
32 °Chard to work on
Temperatures close to 32 °C TW make it impossible for even healthy and accustomed people to work. Even elderly people with respiratory , heart and kidney diseases and strenuous activities are at risk of severe or fatal heat stroke at 26 °C TW.
In the simplified case, if the WBGT increases by 2 °C globally, global labor capacity will drop from 80% to 70 per cent, and if the temperature rises by 4 °C, the efficiency will drop below 60 per cent. This decline in labor capacity will be even greater in tropical areas. In those areas, labor efficiency will drop from 70% to 50 percent with a 2 °C WBGT increase and to 40 percent if a 4 °C increase (Buzan & Huber 2020) .
Deep Overview : India
In 2015 , the TW level in Andhra Pradesh reached 30 °C during the increased summer in India . During that time, despite being accustomed to living in the heat, about 2,500 people died due to heat and due to increased demand for air conditioning, electricity shortages were created in some cities. At that time the livestock mortality rate was also very high. For example, in May 2015 , 17 million chicks died in India (Reuters).
According to an estimate, due to extreme heat and humidity in India, 21% of working hours are being lost under the open sky at this time (McKinsey 2020) . RCP under 8.5 year 2030. It can be increased by 24% and by 2050, 30 per cent (McKinsey 2020).
Scientists have ranked India as a high-risk country in terms of labor productivity during the hottest months , when the WBGT is between 30 and 33 degrees Celsius . In the event of a 3°C rise in global temperature, the WBGT level would rise to 34°C or more and most parts of the country would fall into the ‘ high risk ‘ category in terms of loss of working hours