(GIST OF SCIENCE REPORTER) Wet Bulb Temperature

[November-2022]

Wet Bulb Temperature

We observed extreme heat this summer which is being linked to climate change by experts. The Intergovernmental Panel on Climate Change (IPCC) released its 2022 report on climate change and the extreme heat conditions this year added new technical terms to the vocabulary used by the public in daily-life conversations. “Wet Bulb Temperature” is one of those words.
Wet Bulb Temperature is related to humidity in the air and thus it is crucial in terms of human health. Studies predict that prolonged exposure to wet bulb temperature of 35 degree could be fatal even for a healthy person. The IPCC report says that if carbon emissions are not reduced drastically in the near future, the wet bulb temperature will approach the dangerous level of 35 degrees.
Scientifically, the wet bulb temperature is measured with the help of a thermometer and wrapping a wet wick around the bulb of the thermometer. If the air is dry the evaporation of liquid from the wick cools, and the temperature lowers. The wet bulb temperature is the temperature at which the evaporation process in the wet wick around the thermometer begins. The evaporation process depends on the humidity of the air. If humidity is higher, the wet bulb temperature will be higher.
If wet bulb temperature rises, this means the temperature and humidity have simultaneously risen – the human body finds it hard to sweat and fails to control the body temperature, which may be dangerous. According to the IPCC, humidity rises around 7 percent for each one degree rise in temperature. Global warming and rising temperatures cause rise in humidity and thus higher wet bulb temperature for prolonged times. Similarly, Dry Bulb Temperature is referred to as the ‘air temperature’ measured by the thermometer without being affected by the humidity of the air.