Context:
- Climate change discussions usually focus on sea-level rise, extreme weather, and economic impacts, but often ignore its health consequences.
- It is creating a broad medical crisis by worsening existing diseases and enabling new ones to emerge.
- In India, frequent urban flooding (e.g., Mumbai) leads to waterlogging, which:
- Damages sanitation systems
- Contaminates drinking water
- Increases diseases like cholera, typhoid, hepatitis A, and leptospirosis
- At the same time, drought-affected areas face water scarcity, forcing people to use unsafe water, leading to: Higher cases of diarrhoeal diseases; Chronic dehydration.
- Thus, climate change is intensifying health risks through both excess water and water scarcity.
- This article highlights how climate change has evolved into a major public health emergency in India, impacting disease patterns, air quality, food security, and overall human health.
Expanding Disease Risk Due to Climate Change
- Changing Seasonal Patterns
- Shifts in temperature and rainfall are increasing infections, allergies, and vector-borne diseases.
- Longer pollen seasons and altered cycles are expanding disease timelines and spread.
- Wider Geographic Spread
- Diseases are reaching new regions where populations lack immunity.
- Health systems in these areas are often unprepared to handle outbreaks.
- Rise in Mosquito-Borne Diseases
- Warmer conditions are making new regions suitable for mosquito breeding.
- In Delhi-NCR, dengue cases now peak later (November instead of September) due to prolonged favourable conditions.
- Rise in Mosquito-Borne Diseases
- Warmer conditions are making new regions suitable for mosquito breeding.
- In Delhi-NCR, dengue cases now peak later (November instead of September) due to prolonged favourable conditions.
Climate Change Threats to Human Health
- Rising Air Pollution and Emissions - Higher temperatures increase air conditioning use, leading to more greenhouse gas emissions. This raises levels of PM2.5, which harms multiple organs.
- Impact on Respiratory Health - Fine particles penetrate deep into the lungs, causing: Inflammation and reduced lung function; Worsening of asthma and COPD.
- Cardiovascular and Kidney Effects - PM2.5 damages blood vessels, increasing risks of Hypertension, heart attack, and stroke. Long-term exposure also harms kidneys, leading to reduced filtration and chronic kidney disease.
- Heat Stress and Feedback Loop - Greenhouse gases trap heat, intensifying warming. Heat stress forces the heart to work harder, increasing cardiovascular strain and related illnesses.
- Vulnerable Populations and Heat Impact - Outdoor workers and those without shelter face higher risks. Regions like Odisha, Telangana, and Vidarbha report rising heatstroke deaths. Rising night temperatures reduce recovery time after heat exposure.
- Impact on Infant Health - Extreme heat and pollution are linked to: Preterm births; Low birth weight.
Impact of Climate Change on Food Security and Health
- Disruption of Agriculture and Food Supply - Extreme weather and unseasonal rains disrupt crop cycles and reduce agricultural productivity. This leads to food shortages and rising prices.
- Declining Nutritional Quality - Reduced crop quality and higher costs create: Micronutrient deficiencies; Chronic malnutrition, especially among children.
- Impact on Dairy and Nutrition - Heat stress reduces milk production in cattle. This affects infant and child nutrition.
- Health Consequences - Food insecurity leads to: Weakened immunity; Increased disease vulnerability, particularly among children and the elderly.
Climate Change as a Present Health Crisis
- Climate change is no longer a distant threat but a current public health issue in India.
- It is a multifaceted challenge, and recognising it as a medical emergency is essential for urgent action.
