Tamil Nadu Declares Heatwave a State Disaster

The Tamil Nadu government recently classified heatwaves as a state-specific disaster. This decision comes amid alarming reports of rising temperatures and increasing heat-related fatalities. The World Meteorological Organization declared 2023 as the hottest year on record. The frequency of heatwaves has surged, largely due to human-induced climate change.

About Heatwaves

A heatwave is a prolonged period of excessively hot weather. It can occur alongside high humidity but is primarily defined by regional standards. The India Meteorological Department (IMD) specifies that a heatwave in plains occurs when temperatures reach at least 40°C. In hilly regions, the threshold is 30°C.

Health Impacts of Heatwaves

Extreme heat poses health risks. Studies indicate a strong correlation between heatwaves and increased mortality rates. Heat-related illnesses range from heat exhaustion to heat stroke. Vulnerable populations include children, the elderly, and those with pre-existing health conditions. The World Health Organization reported an 85% increase in heat-related mortality among individuals over 65 from 2000-2004 to 2017-2021.

The Role of Wet Bulb Temperature

Wet bulb temperature measures the lowest temperature a surface can cool due to evaporation. It combines temperature and humidity, making it crucial for understanding heat stress. A wet bulb temperature exceeding 35°C for extended periods can lead to hyperthermia, posing severe health risks.

Governmental Response Strategies

Governments must address both immediate and long-term challenges posed by heatwaves. Immediate actions include preparing health facilities, stockpiling essential supplies, and ensuring access to water and shelter. Long-term strategies should focus on mitigating climate change and addressing systemic issues like poverty and urban planning.

Historical Context of Heatwaves in India

India has a history of severe heatwaves. Notable instances include the 1998 heatwave, which was deemed the worst in 50 years, and the 2003 heatwave in Andhra Pradesh, causing over 3,000 deaths. The summer of 2024 saw extreme temperatures, with Churu in Rajasthan reaching 50.5°C, marking the highest in eight years.

Future Projections

Research indicates that densely populated agricultural regions in South Asia will face the most intense heatwaves in the future. This poses an important threat to public health and agricultural productivity in a region already vulnerable to climate-related hazards.

Questions for UPSC:

1. Critically analyse the impact of heatwaves on public health in India.
2. Explain the significance of wet bulb temperature in assessing heat stress.
3. What are the immediate and long-term strategies governments should adopt to mitigate heatwave impacts?
4. Comment on the historical trends of heatwaves in India and their implications for future climate policy.
5. With suitable examples, underline the vulnerabilities faced by different demographics during extreme heat events.

1. Critically analyse the impact of heatwaves on public health in India.

Heatwaves pose an important public health crisis in India, exacerbated by rising temperatures linked to climate change. The correlation between extreme heat and increased mortality rates is well-documented. Research indicates that longer and more intense heatwaves lead to higher mortality risks, particularly among vulnerable populations such as the elderly, children, and those with pre-existing health conditions.

• Direct Health Effects: Heat-related illnesses, including heat exhaustion and heat stroke, are immediate consequences of extreme temperatures. The India Meteorological Department (IMD) has established that temperatures exceeding 40°C in plains can trigger these conditions, which can be fatal without prompt medical intervention.
• Indirect Health Effects: Extreme heat also exacerbates chronic health issues. For instance, heat stress can lead to renal insufficiency, cardiovascular diseases, and respiratory problems. Vulnerable populations, including those who work outdoors, are particularly at risk.
• Socioeconomic Factors: The impact of heatwaves is disproportionately felt in low-income communities, where access to healthcare, shelter, and nutrition is limited. Poverty exacerbates vulnerability, making it difficult for affected individuals to adapt to extreme heat.
• Mortality Statistics: The World Health Organization reported an 85% increase in heat-related mortality among individuals over 65 from 2000-2004 to 2017-2021. This alarming trend puts stress on the urgent need for targeted public health interventions.
• Public Health Infrastructure: The existing healthcare system in India is often ill-equipped to handle the surge in heat-related illnesses during heatwaves. Hospitals may lack sufficient resources, such as intravenous fluids and cooling systems, to treat affected individuals effectively.

Thus, the impact of heatwaves on public health in India is deep and multifaceted. Addressing this crisis requires a comprehensive approach that includes improving healthcare infrastructure, increasing public awareness, and implementing adaptive strategies for vulnerable populations.

2. Explain the significance of wet bulb temperature in assessing heat stress.

Wet bulb temperature (WBT) is important metric for understanding heat stress, particularly in humid climates like India. It represents the lowest temperature to which a surface can be cooled by evaporative cooling, combining both temperature and humidity into a single measure. The significance of wet bulb temperature in assessing heat stress can be summarized as follows:

• Human Thermal Comfort: WBT is essential for evaluating human thermal comfort. When the WBT exceeds 35°C for extended periods, the human body struggles to dissipate heat, leading to hyperthermia, heat exhaustion, or even heat stroke. This threshold is critical for public health advisories during extreme heat events.
• Evaporation and Cooling: WBT accounts for humidity levels, which directly affect the body’s ability to cool itself through sweating. In high humidity, sweat evaporation is hindered, reducing the body’s cooling efficiency and increasing the risk of heat-related illnesses.
• Climate Change Implications: As global temperatures rise, WBT is becoming a more critical factor in climate change discussions. Projections indicate that regions with high humidity will experience more frequent and intense heat stress events, impacting agricultural productivity and public health.
• Guiding Policy and Preparedness: About WBT can help policymakers develop targeted interventions during heatwaves. For instance, public health guidelines can be established to protect vulnerable populations by advising on hydration, work hours, and access to cooling facilities.
• Research and Monitoring: Continuous monitoring of WBT in various regions can provide valuable data for climate research and public health planning. It can help identify areas at risk of extreme heat stress, allowing for timely interventions.

In this way, wet bulb temperature is a vital indicator for assessing heat stress and its potential impacts on human health, particularly in regions like India, where climate change is intensifying heat-related risks.

3. What are the immediate and long-term strategies governments should adopt to mitigate heatwave impacts?

Governments must adopt a multifaceted approach to mitigate the impacts of heatwaves, encompassing both immediate and long-term strategies.

Immediate Strategies:

• Establish Cooling Centers: Create accessible cooling centers equipped with air conditioning and medical support to provide refuge for vulnerable populations during extreme heat events.
• Public Awareness Campaigns: Launch campaigns to educate citizens about heat-related illnesses, hydration, and protective measures during heatwaves, particularly targeting communities at high risk.
• Healthcare Preparedness: Ensure hospitals and health centers are stocked with necessary medical supplies such as oral rehydration solutions (ORS) and intravenous fluids to treat heat-related conditions effectively.
• Reschedule Working Hours: Implement policies to adjust working hours for outdoor laborers to avoid peak heat times, thereby reducing exposure to extreme temperatures.

Long-term Strategies:

• Urban Planning: Invest in urban planning that incorporates green spaces, shaded areas, and reflective materials to mitigate the urban heat island effect, thus reducing overall temperatures in cities.
• Climate Change Mitigation: Address the root causes of climate change by promoting renewable energy, reducing greenhouse gas emissions, and implementing sustainable agricultural practices.
• Infrastructure Resilience: Enhance infrastructure resilience to withstand extreme weather events, including retrofitting buildings and public spaces to improve heat resistance.
• Health System Strengthening: Strengthen health systems to better manage heat-related illnesses through training healthcare providers and improving emergency response capabilities.

By implementing these immediate and long-term strategies, governments can reduce the health risks associated with heatwaves and improve overall resilience to climate change.

4. Comment on the historical trends of heatwaves in India and their implications for future climate policy.

India has experienced a notable increase in the frequency and intensity of heatwaves over the past few decades, with several historical instances denoting this trend. The implications of these trends for future climate policy are deep.

• Historical Context: Significant heatwaves in India include the devastating 1998 heatwave, which was deemed the worst in 50 years, and the 2003 heatwave in Andhra Pradesh that caused over 3,000 deaths. More recently, the summer of 2024 saw extreme temperatures reaching 50.5°C in Rajasthan, indicating a worrying trend.
• Climate Change Link: The increasing frequency of heatwaves correlates strongly with anthropogenic climate change, as brought into light by the Intergovernmental Panel on Climate Change (IPCC). This relationship necessitates urgent policy responses to mitigate greenhouse gas emissions and adapt to changing climate patterns.
• Public Health Implications: The rising incidence of heatwaves poses public health challenges, particularly affecting vulnerable populations. Historical data indicates that mortality rates during heatwaves have increased, emphasizing the need for health-focused climate policies.
• Adaptation Strategies: Historical trends necessitate the development of robust adaptation strategies in climate policy. This includes enhancing urban resilience, improving public health infrastructure, and implementing early warning systems for extreme heat events.
• International Cooperation: Given the transboundary nature of climate change, India must engage in international cooperation to share best practices and technologies for heatwave mitigation and adaptation.

Thus, the historical trends of heatwaves in India tell the urgent need for comprehensive climate policies that address both mitigation and adaptation to protect public health and ensure sustainable development.

5. With suitable examples, underline the vulnerabilities faced by different demographics during extreme heat events.

Extreme heat events disproportionately affect various demographics, exacerbating existing vulnerabilities. Here are some key examples:

• Elderly Population: Older adults are particularly vulnerable due to physiological changes that reduce their ability to regulate body temperature. For instance, the World Health Organization reported an 85% increase in heat-related mortality among individuals over 65 from 2000-2004 to 2017-2021, denoting their heightened risk during heatwaves.
• Children: Young children are susceptible to heat-related illnesses due to their smaller body size and higher metabolic rates. Heat exposure can affect their development and learning capabilities, as noted in research from Harvard University, which links extreme heat to adverse health outcomes in early childhood.
• Outdoor Workers: Laborers in agriculture and construction often work in extreme heat conditions, increasing their risk of heat exhaustion and heat stroke. For example, during the severe heatwave in 2024, many outdoor workers in India suffered from heat-related ailments, leading to health crises.
• Poor Communities: Low-income populations often lack access to adequate shelter, healthcare, and nutrition, making them more vulnerable to heatwaves. For instance, during the 2003 heatwave in Andhra Pradesh, impoverished communities faced higher mortality rates due to insufficient resources to cope with extreme heat.
• Pregnant Women: Extreme heat can adversely affect pregnant women, leading to complications such as heat stress and preterm labor. Research indicates that high temperatures during pregnancy can have lasting effects on fetal development and maternal health.

In this way, different demographics face unique vulnerabilities during extreme heat events. Addressing these vulnerabilities requires targeted interventions that consider the specific needs of each group, ensuring that public health responses are inclusive and effective.