Climate change reshaping disease patterns, straining health systems, finds report 

Why in the News?

Climate change is no longer a distant environmental issue; it is already affecting public health in India. The report “Under the Weather: India’s Climate-Health Challenges” shows a clear shift, from occasional disease outbreaks to a larger, ongoing health crisis caused by changing climate patterns. With nearly 40% of districts at high risk from extreme weather events, it highlights a turning point where climate and health policies must be addressed together, not separately.

Why is climate change now being seen as a public health crisis in India?

1. Health-risk multiplier: Climate variability amplifies both communicable and non-communicable diseases, increasing overall disease burden and healthcare pressure.
   1. Vector-borne diseases (Communicable): Rising temperatures and erratic rainfall expand mosquito habitats, increasing diseases like dengue and malaria. Example: Himachal Pradesh (Shimla) and parts of Jammu & Kashmir have recently reported dengue cases, regions that were earlier too cold for such outbreaks.
   2. Water-borne diseases (Communicable): Flooding contaminates water sources, leading to outbreaks of cholera and hepatitis. Case study: Kerala floods (2018) led to spikes in leptospirosis and diarrhoeal diseases due to stagnant and contaminated water.
   3. Heat-related illnesses (Non-communicable): Extreme heat increases heat strokes, dehydration, and cardiovascular stress. Case study: India Heatwave (2015) caused over 2,000 deaths, especially in Andhra Pradesh and Telangana, overwhelming hospitals.
   4. Air pollution-linked diseases (Non-communicable): Climate change worsens air quality (e.g., higher PM2.5), increasing respiratory and cardiac illnesses. Example: Delhi NCR sees seasonal spikes in asthma, COPD, and heart conditions, especially during winter inversion periods.
   5. Maternal and child health impacts: Heat stress and pollution increase risks in pregnancy and early childhood. Case study: Studies in South Asia show higher preterm births during heatwaves; infants are more vulnerable due to poor heat regulation.
   6. Livelihood-health linkage: Climate shocks reduce income, leading to malnutrition and weakened immunity. Example: Drought-prone regions of Maharashtra (Marathwada) show increased child malnutrition and related diseases during repeated drought years. 
2. Scale of vulnerability: Nearly 40% of districts face high risk from extreme weather events, indicating systemic exposure.
3. Shift in disease ecology: Warmer temperatures and erratic rainfall expand disease vectors into new geographies.
4. Systemic disruption: Climate events impact livelihoods, healthcare access, and infrastructure simultaneously.

How is climate change reshaping the disease landscape in India?

1. Vector-borne expansion: Changing rainfall patterns and warming temperatures expand diseases like dengue and malaria into previously unaffected regions such as Shimla, Himalayan foothills, and Jammu & Kashmir; Pune identified as a major dengue hotspot.
2. Water-borne diseases: Increased flooding triggers outbreaks of cholera and hepatitis, linked to contaminated water sources.
   1. Example: Assam floods (2022) led to a surge in acute diarrhoeal diseases and suspected hepatitis cases, as submerged sanitation systems contaminated water sources across districts like Barpeta and Nagaon.
   2. Example: Mumbai floods (2005) triggered outbreaks of leptospirosis, hepatitis A, and gastroenteritis, due to overflow of drainage systems and exposure to polluted water.
3. Non-communicable diseases (NCDs): Heat exposure increases cardiovascular mortality, while air pollution worsens respiratory illnesses and chronic conditions.
   1. A meta-analysis in Environmental Research shows that each 1°C rise above ~29°C increases all-cause mortality by ~3.9%, highlighting strong cardiovascular and systemic stress due to heat.
4. Climate-sensitive transmission: Altered environmental conditions change pathogen survival and transmission dynamics.
   1. Cholera bacteria survival: Warmer sea surface temperatures and plankton blooms support Vibrio cholerae survival. Example: West Bengal coastal regions (Sundarbans) report recurrent cholera outbreaks linked to changing coastal water conditions.

Which populations are disproportionately affected and why?

1. Vulnerable groups: Rural populations, informal workers, women, and children face highest risks due to limited adaptive capacity.
2. Occupational exposure: Outdoor workers experience productivity loss and health risks; India lost an estimated 160 billion labour hours in 2021 due to heat exposure.
3. Gendered impacts: Women face higher exposure and health burdens due to socio-economic constraints and caregiving roles.
4. Inequality deepening: Climate impacts exacerbate existing socio-economic inequalities and health disparities.

What are the direct and indirect health impacts of climate change?

1. Heat stress: Extreme heat linked to 16% increase in odds of preterm birth; increases risks for infants and pregnant women.
2. Air pollution linkages: Rising PM2.5 levels associated with hypertension, pre-eclampsia, and gestational blood pressure disorders.Child vulnerability: Infants have limited thermoregulation, increasing susceptibility to heat stress and respiratory illnesses.
3. Livelihood-health nexus: Climate shocks reduce income and productivity, reinforcing cycles of vulnerability.

How does climate change disrupt healthcare systems and access?

1. Infrastructure damage: Floods and cyclones damage hospitals, disrupt supply chains of medicines and vaccines.
2. Access barriers: Remote areas face healthcare exclusion during disasters, leading to untreated illnesses.
3. Service disruption: Climate events reduce continuity of care and strain emergency response systems.
4. System overload: Increased disease burden overwhelms already fragile public health infrastructure.

What measures have been taken to address climate-health challenges?

1. Policy integration: Initiatives like the National Action Plan on Climate Change and Human Health aim to align climate and health strategies.
2. Localized adaptation:State-level action plans focus on region-specific vulnerabilities and responses.
   1. Heat Action Plans (HAPs): State and city-level plans customize responses to local heat risks through early warnings, cooling centers, and hospital preparedness. Example: Ahmedabad Heat Action Plan (Gujarat)—India’s first HAP, reduced heatwave mortality by introducing early warning systems, public advisories, and training for healthcare workers.
   2. Flood-resilient health planning: States prone to floods integrate disease surveillance and emergency health response. Example: Odisha developed disaster-resilient health infrastructure and rapid response systems after the 1999 super cyclone, ensuring minimal disease outbreaks during recent cyclones like Fani (2019).
   3. Vector-borne disease control: Region-specific strategies target local disease patterns and climate conditions. Example: Kerala uses pre-monsoon mosquito control drives and decentralized surveillance to manage dengue and malaria risks.
   4. Drought and nutrition linkage: States facing water stress integrate health and nutrition interventions. Example: Maharashtra (Marathwada) implements nutrition programs and water management schemes to address drought-linked malnutrition and health issues. 
3. Early warning systems: Expansion of climate-linked disease surveillance and forecasting mechanisms.
4. Cross-sectoral convergence: Efforts to integrate health, environment, and disaster management frameworks.

What are the key gaps and challenges in India’s response?

1. Data fragmentation: Lack of disaggregated data linking climate events to health outcomes limits targeted interventions.
2. Funding constraints: Insufficient investment in climate-resilient healthcare infrastructure.
3. Awareness deficit: Limited public understanding reduces adaptive capacity and risk preparedness.
4. Governance gaps: Weak coordination across government, private sector, and civil society. 

Conclusion

Climate change is transforming India’s health landscape from episodic crises to a chronic systemic challenge. Addressing this requires integrating climate resilience into public health systems, strengthening data-driven governance, and prioritizing vulnerable populations to ensure equitable health outcomes.

PYQ Relevance

[UPSC 2017] Climate Change’ is a global problem. How India will be affected by climate change? How Himalayan and coastal states of India will be affected?

Linkage: Climate change is a recurring GS-3 theme, with UPSC repeatedly focusing on its impacts, vulnerability, and disasters. This article extends that dimension by linking it to public health risks and disease patterns, enriching answers with current relevance.