Health Impacts of Climate Change

Pathways Overview - Climate's Health Web

• Direct Impacts:
  • Extreme weather events (heatwaves, floods, cyclones): Cause immediate injuries, fatalities, displacement, and heat stress.
• Indirect Impacts (Ecosystem-mediated):
  • Altered vector ecology: ↑ Vector-borne diseases (VBDs) like Malaria, Dengue.
  • Water & food systems: ↑ Water-borne (Cholera) & food-borne diseases; food insecurity, malnutrition from crop failures.
  • Air quality: Worsened by wildfires, dust; ↑ respiratory & cardiovascular diseases.
• Indirect Impacts (Socio-economic & Demographic):
  • Mental health: Anxiety, depression, PTSD.
  • Population displacement, resource conflicts.
  • Overburdened health infrastructure.

⭐ Climate change is recognized by WHO as the single biggest health threat facing humanity.

Direct Health Effects - Weather's Wrath

• Heatwaves: ↑ Morbidity/mortality.
  • Heat exhaustion, heat stroke (medical emergency).
  • Exacerbation: Cardiovascular, respiratory, renal diseases.
  • Dehydration, electrolyte imbalance.
• Extreme Weather Events (Floods, Cyclones, Storms):
  • Injuries, trauma, drowning.
  • ↑ Water-borne diseases (cholera, typhoid, leptospirosis).
  • ↑ Vector-borne diseases (malaria, dengue due to stagnant water).
  • Displacement, mental health impacts.
• Wildfires: Burns, severe respiratory distress (PM2.5 inhalation), eye irritation.
• Droughts: Malnutrition, food insecurity, water scarcity.

⭐ Heat stroke is a life-threatening condition defined by core body temperature >40°C (104°F) with central nervous system dysfunction.

Infectious Disease Surge - Germs on Warm

• ↑ Temp & altered rainfall → favorable conditions for pathogens/vectors.
• Vector-Borne (VBDs):
  • Mosquitoes: Malaria (↑ spread), Dengue, Chikungunya, JE.
  • Ticks: KFD.
• Water-Borne:
  • Floods/droughts → contamination.
  • Cholera, Typhoid, Hepatitis A/E, Lepto.
• Food-Borne: ↑ Temp → ↑ bacterial growth (e.g., Salmonella).

⭐ Dengue vectors (Aedes) show ↑ breeding in urban heat islands & post-monsoon stagnation, expanding transmission.

Systemic Health Risks - NCDs & Nutrition

• Air pollution (wildfires, ozone): ↑Cardiovascular (IHD, stroke) & Respiratory (Asthma, COPD) NCDs.
• Extreme heat: ↑Cardiovascular strain, heatstroke, acute kidney injury; worsens chronic kidney disease.
• Food Insecurity:
  • ↓Crop yields & nutritional quality (↓protein, zinc, iron) → Malnutrition (stunting, wasting), micronutrient deficiencies.
• Water Insecurity: Affects hygiene, food safety; linked to kidney disease from dehydration/contaminants.
• Mental health: Climate anxiety, PTSD → ↑NCD risk.

⭐ Climate change's agricultural impact may put 1-29 million more people at risk of hunger by 2050, severely affecting child nutrition.

India's Vulnerabilities - Unequal Burdens

• Climate change disproportionately impacts vulnerable groups, widening health disparities.
• Key Vulnerable Populations:
  • Low-income communities: ↓ adaptive capacity, ↑ exposure.
  • Coastal dwellers: Sea-level rise, ↑cyclones, saline intrusion.
  • Farmers & outdoor workers: Extreme heat, crop failures, ↓ livelihoods.
  • Elderly, children, pregnant women: Physiological susceptibility.
  • Tribal populations: Forest dependence, displacement, loss of traditional medicine.
  • Urban poor: Heat islands, overcrowding, poor sanitation.
• Regional Hotspots & Risks:
  • Himalayas: Glacial melt (GLOFs), water insecurity.
  • Coasts: Cyclones, storm surges, ↑vector-borne diseases.
  • Indo-Gangetic plains: Floods, heatwaves, food insecurity.

  ⭐ Over 75% of Indian districts are vulnerable to extreme climate events. oka

High‑Yield Points - ⚡ Biggest Takeaways

• Increased vector-borne diseases (Malaria, Dengue) from altered vector ecology.
• Rise in heat-related illnesses (heat stroke, exhaustion) in vulnerable populations.
• Higher risk of water-borne diseases (Cholera, Typhoid) due to water contamination.
• Exacerbation of respiratory illnesses (Asthma, COPD) from poor air quality.
• Food insecurity and malnutrition due to crop failures and reduced agricultural output.
• Mental health impacts like anxiety and PTSD from extreme weather events.
• Worsening of NCDs, especially cardiovascular and respiratory diseases.