- October 29, 2021
- Posted by: OptimizeIAS Team
- Category: DPN Topics
Subject – Environment
Context – Heat waves likely to last ‘25 times longer’ in India by another 2-4 decades, says climate report
- The heatwaves in India are likely to “last 25 times longer by 2036-2065” if carbon emissions remain high and push global temperature rise to 4 degrees Celsius by the end of the century, according to an international climate report published October 28, 2021 covering G20 countries.
- The heatwaves will last “over five times longer if global temperature rise is constrained to about 2°C, and one and a half times longer if emissions are very low and temperature rise only reaches 1.5°C”.
- The G20 is an inter-governmental forum comprising 19 countries and the European Union (EU). It works to address major economical issues, including those related to international financial stability, climate change mitigation and sustainable development.
- Climate change will have devastating impacts on every G20 member, the report said.
- The report said the G20 needs to rapidly cut its emissions, which account for 80 per cent global greenhouse gas emissions, to stabilise economies.
What are heat waves?
- A Heat Wave is a period of abnormally high temperatures, more than the normal maximum temperature that occurs during the summer season in the North-Western parts of India. Heat Waves typically occur between March and June, and in some rare cases even extend till July. The extreme temperatures and resultant atmospheric conditions adversely affect people living in these regions as they cause physiological stress, sometimes resulting in death.
- The Indian Meteorological Department (IMD) has given the following criteria for Heat Waves :
- Heat Wave need not be considered till maximum temperature of a station reaches atleast 40°C for Plains and atleast 30°C for Hilly regions
- When normal maximum temperature of a station is less than or equal to 40°C Heat Wave Departure from normal is 5°C to 6°C Severe Heat Wave Departure from normal is 7°C or more
- When normal maximum temperature of a station is more than 40°C Heat Wave Departure from normal is 4°C to 5°C Severe Heat Wave Departure from normal is 6°C or more
- When actual maximum temperature remains 45°C or more irrespective of normal maximum temperature, heat waves should be declared. Higher daily peak temperatures and longer, more intense heat waves are becomingly increasingly frequent globally due to climate change. India too is feeling the impact of climate change in terms of increased instances of heat waves which are more intense in nature with each passing year, and have a devastating impact on human health thereby increasing the number of heat wave casualties.
Health Impacts of Heat Waves
The health impacts of Heat Waves typically involve dehydration, heat cramps, heat exhaustion and/or heat stroke. The signs and symptoms are as follows:
- Heat Cramps: Ederna (swelling) and Syncope (Fainting) generally accompanied by fever below 39°C i.e.102°F.
- Heat Exhaustion: Fatigue, weakness, dizziness, headache, nausea, vomiting, muscle cramps and sweating.
- Heat Stoke: Body temperatures of 40°C i.e. 104°F or more along with delirium, seizures or coma. This is a potential fatal condition.