Food and water security
Big idea: Climate change threatens food security and water security through changing rainfall, temperatures, and extreme events.
Impacts on agriculture
- Changed growing conditions: Some crops may fail; growing zones shift poleward
- Water stress: Drought reduces yields; changed monsoon patterns affect irrigation
- Extreme weather damage: Floods, storms, heatwaves destroy crops
- New pests and diseases: Warmer temperatures allow expansion to new areas
- Soil degradation: Increased erosion from intense rainfall; desertification
Impacts are uneven — some regions may benefit (longer growing seasons), but most will face challenges. LEDCs are often most vulnerable.
Water resources
- Glacier melt: Initially more water, then less as glaciers disappear
- Changed precipitation: Some regions drier, others wetter; more flooding
- Groundwater depletion: Increased demand during droughts
- Saltwater intrusion: Sea level rise contaminates coastal aquifers
- Water quality: Higher temperatures increase algal blooms
Exam tip: Essay questions often ask about impacts on societies. Structure your answer by sector: food, water, health, infrastructure, economy.
Health, infrastructure and displacement
Big idea: Climate change affects human health directly (heat, disasters) and indirectly (disease, nutrition). It also threatens infrastructure and may force millions to relocate.
Health impacts
- Heat-related illness: Heatstroke, dehydration, cardiovascular stress
- Vector-borne diseases: Malaria, dengue expanding to new areas
- Waterborne diseases: Flooding spreads cholera, typhoid
- Air quality: Higher temperatures increase ground-level ozone; wildfire smoke
- Malnutrition: Reduced crop yields affect food availability
- Mental health: Climate anxiety, trauma from disasters, displacement stress
Infrastructure and displacement
- Coastal flooding: Threatens ports, cities, roads in low-lying areas
- Permafrost thaw: Damages buildings, roads, pipelines in Arctic regions
- Storm damage: More intense hurricanes/cyclones destroy infrastructure
- Climate refugees: People forced to move due to sea level rise, drought, or disasters
- Economic costs: Damage repair, lost productivity, insurance costs
Climate justice issue: Those who contributed least to climate change (LEDCs, small island nations) often face the worst impacts and have the fewest resources to adapt.
Exam tip: In discuss or evaluate questions, consider who is affected and discuss equity issues.