3.2 Human impact on biodiversity
- Syllabus
- First assessment 2026
- Topic
- 3.2
- Level
- HL
• Direct: overharvesting, poaching, illegal pet trade
• Indirect: habitat loss, climate change, pollution, invasive alien species
• Most ecosystems subject to multiple impacts
• Effects amplified when combined
• Reduce biodiversity through competition, predation, diseases/parasites
• Global conservation status assessment
• Based on: population numbers, rate changes, breeding potential, geographic range, threats
• Status ranks: least concern (LC) to extinct (EX)
• Publicizes species vulnerability
• Allows selection of conservation priorities and management strategies
• Extinct species due to human activity
• Critically endangered species
• Species improved by intervention
• Overexploitation of shared natural resources
• Tension between individual self-interest and sustainable development
• Examples: fish stocks, ocean plastic pollution
• Under threat from habitat destruction
• Significant loss risk, especially in tropical biomes
• Sites contributing to global biodiversity persistence
• Hold species at extinction risk or ecosystems at collapse risk
• Exploitation vs. sustainable development vs. conservation
• Example: palm oil plantations in Malaysia/Indonesia
• Can be more sustainable
• Challenges: population growth, economic development, climate change, lack of support
• Must be considered when addressing biodiversity loss
• Impacts on indigenous and marginalized communities
• Species extinctions have crossed critical threshold
• Could lead to Earth system tipping point