Current Affairs 1st June 2024 for UPSC Prelims Exam

Heatwaves

Context: Large parts of India (especially states like Delhi, Bihar, Odisha, and Gujarat) are experiencing an intense and prolonged heatwave with record-breaking temperatures which is leading to fatalities.

What are the Impacts?

• Impact of Urbanization on Nighttime Temperatures: Research by the Indian Institute of Technology, Bhubaneswar, covering the period 2003-2020 across 141 Indian cities, found an average increase in nighttime temperatures of 0.52 +/- 0.19 degrees Celsius per decade.
  • The study, published in Nature, attributes 60% of this warming to urbanisation alone.
• Changes in Temperature Variance: A study from the Centre for Science and Environment (CSE) noted a reduction in the temperature difference between day and night over time.
  • While nights were 6.2-13.2 degrees Celsius cooler than days in the decade 2001-2010, the cooling difference reduced to 6.2-11.5 degrees Celsius in the decade 2014-2023, indicating less relief from heat at night.
• Health Risks from Humidity and Warmer Nights: Increased temperatures and humidity impair the body’s ability to cool itself through sweating.
  • Doctors highlighted the health risks including dehydration, salt imbalances, and reduced blood flow to organs due to increased sweating.
  • High nighttime temperatures further prevent the body from recuperating, increasing the risk of heat-related illnesses like heat stroke.
• Heat-Related Mortality: A study from Science Advances linking data from 1960-2009 showed a 146% increase in the probability of heat-related mortality events affecting more than 100 people, correlating with the rise in average summer temperatures in India.

Urban Heat Island Effect

Context:

• The year 2023 was recorded as the hottest year ever, with global average temperatures reaching 1.45° C above pre-industrial levels, nearing the 1.5° C limit set by the Paris Agreement.
• Predictions for 2024 suggest similar temperature trends, with global emissions still rising and climate impacts, including heatwaves, intensifying, especially across the Indian sub-continent.

Urban Heat Island (UHI) Phenomenon

• The phenomenon where cities experience higher temperatures than surrounding areas, particularly at night is known as the Urban Heat Island (UHI) effect.
• This effect is exacerbated by urban structures such as buildings and roads made from heat-absorbing materials like concrete, which retain and re-emit heat.
• Reduced greenery in urban settings further intensifies this effect, especially during nighttime, making the environment significantly warmer compared to less urbanised, greener areas.
• Chennai, a coastal city, faces additional challenges with high humidity that impairs the cooling effect of perspiration, increasing risks of heat stress and heat stroke.
• This, combined with high humidity, can create conditions that are “near the limits of human survivability” according to the World Health Organization.

Impact of UHI in Chennai

• Heat maps indicate UHI adds between 2° to 4° C to temperatures in Chennai compared to nearby rural areas.
• Wet-bulb temperatures reaching 38.5° C are nearing human survivability limits, as per the World Health Organization.
• Official heatwave conditions are declared in coastal areas like Chennai when temperatures exceed 37° C and are 4.5° C above normal, a threshold easily surpassed due to UHI effects.

Responses and Plans

• India has implemented Heat Action Plans (HAP) at national, state, and district levels to mitigate heat-related morbidity and mortality, particularly among vulnerable groups.
• The National Disaster Management Authority (NDMA) provided guidelines that include early warning systems, staggered work hours for outdoor workers, and provisions for shade, water, and oral rehydration.

Initiatives and Potential Improvements

• Chennai’s Climate Action Plan (CCAP)outlines various strategies to address UHI and enhance urban liveability, though there is potential for more detailed and targeted actions.
• Increasing green cover is emphasised as a key strategy for sustainable urban development, recommended by UN Habitat to be accessible within 400 metres for all citizens.
• Chennai has some of the lowest green cover among Indian metros but has initiated promising projects like “miyawaki forests.”
• The Chennai Metropolitan Development Authority (CMDA) is developing more detailed heat maps for better localised planning.

Recommendations from the Study

• Increasing green cover in Chennai Metropolitan Area (CMA) to 25% could reduce UHI by about 1.5° C and absorb around 10% of CO2 emissions.
• Energy-efficient air conditioning and building practices (such as green building) could reduce UHI further by about 3° C and offer significant energy savings.
• Additional measures include using permeable materials for pavements, enhancing shrubbery, applying reflective paint, and promoting public transport, particularly electric buses, to reduce personal vehicle use.

Examples, Case Studies and Data

• India’s Export (GS 3): India has managed to deliver approximately 73,000 tonnes, or 7%, of the agricultural commodities it promised to strategic partners under bilateral agreements.
  • Factors behind India’s limited supply of pledged agricultural commodities:
    • Domestic Price Control Measures: Efforts to stabilise domestic prices have impacted India’s ability to fulfill export commitments.
    • Uncompetitive Pricing: Indian exporters, under government-to-government (G2G) deals, offer prices higher than other major producers, making exports less attractive.
    • Prioritising Domestic Supply: The Indian government has restricted export quantities to ensure sufficient supplies for domestic consumption.

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