Introduction
A central theme in IB Environmental Systems and Societies (ESS) is the relationship between humans and ecosystems. The new syllabus, first assessed in 2026, places even greater emphasis on understanding how human actions alter ecological balance.
From deforestation to pollution, agriculture to urbanization, human activity drives change at both local and global scales. In ESS, you’ll study these impacts through a systems-thinking lens, looking at feedback loops, sustainability, and conservation strategies.
Quick Start Checklist: Human Impacts in ESS
- Deforestation and land use change disrupt biodiversity and nutrient cycles.
- Agriculture and food production affect soil, water, and energy flows.
- Pollution (air, water, soil) damages ecosystems and human health.
- Overexploitation (fishing, hunting, resource use) destabilizes populations.
- Climate change shifts species distributions and ecosystem stability.
- Tested through case studies, data analysis, and essay evaluation.
Major Human Impacts on Ecosystems
1. Deforestation
- Reduces carbon storage and contributes to climate change.
- Causes habitat loss and species extinction.
- Leads to soil erosion and reduced fertility.
2. Agriculture
- Intensive farming increases yields but depletes soils and adds chemical pollution.
- Irrigation affects freshwater systems.
