The World Bank warned that India could become one of the first places where wet-bulb temperatures routinely exceed 35°C. Which of the following statements best reflect(s) the implication of the above-said report?
- Peninsular India will most likely suffer from flooding, tropical cyclones and droughts.
- The survival of animals including humans will be affected as shedding of their body heat through perspiration becomes difficult.
Select the correct answer using the code given below:
- I only
- II only
- Both I and II
- Neither I nor II
Explanation
Statement I is incorrect
- A wet-bulb temperature of 35°C is considered the maximum limit of humidity that humans can handle. Beyond this, the body can no longer effectively cool itself via perspiration. Internationally, the agreed-upon safe wet-bulb temperature is below 30°C, with a maximum of 35°C. Between 30°C and 35°C, the human body experiences hyperthermia, in which body temperature rises, leading to discomfort and effects on various organs, including the brain and heart. Flooding, tropical cyclones, and droughts are among the broad effects of climate change. Wet-bulb temperature, however, is specifically about heat stress and how the body copes with hot, humid conditions, not about weather events such as floods or cyclones. So, while climate change can lead to both high wet-bulb temperatures and extreme weather, the World Bank’s warning about a 35°C wet-bulb temperature focuses on human survivability and heat stress.
Statement II is correct
- At wet-bulb temperatures of 35°C or higher, the air is so hot and humid that sweat can no longer evaporate effectively. Evaporation of sweat is the primary cooling mechanism for humans (and many animals). If this stops working, body temperature rises uncontrollably, leading to heat stroke and possible death, even in shade and with access to water.
