Biodiversity & Humans

Population Growth and Agricultural Demand

• Global population has increased dramatically over the last 500 years—now exceeding 8 billion.

• Agricultural productivity has had to increase to avoid famine and starvation.

• Achieved through: intensive farming, chemicals (fertilisers, pesticides, weed killers), mechanisation, use of marginal land, and genetically modified organisms (GMOs)—e.g., wheat resistant to mould or drought-resistant crops.

• Consequences: Pollution, climate change, desertification, deforestation, and biodiversity loss have led to degraded ecosystems and irreversible change.

Sustainable Development

• Sustainable development requires balancing population size with conservation of remaining ecosystems.

• This reduces pressure on ecosystems to provide more while maintaining human wellbeing.

• Nature takes time to recover—policies put in place decades ago are beginning to take effect; the rate of biodiversity decline is slowing.

The Four Ecosystem Service Categories

Positive vs Negative Feedback

• Positive feedback (population increase → biodiversity management): More people can lead to conservation efforts, awareness, and policy action.

• Negative feedback (population increase → biodiversity destruction): More people increase demand for resources, land conversion, and pollution—destroying biodiversity.

• Responses to environmental footprint can be either positive or negative depending on policies and behaviour.

What the EKC Proposes

• The Environmental Kuznets Curve hypothesises an inverted-U relationship between economic development and environmental degradation.

• Initially: Economic development leads to deterioration—industrialisation, resource extraction, pollution.

• As growth peaks: Society turns to improving environmental management; degradation levels reduce.

• Implication: Economic growth may eventually become beneficial to the environment—e.g., UK recycling, emission regulations.

When to Apply

• Useful for understanding the hypothesised trajectory of many HDEs.
• To be effective, targeted policies and management are needed to align economic growth with environmental needs for long-term sustainability.

Pollution is Multi-Factorial

• Pollution is not solely a product of income—many factors matter: government regulations, population levels, level of a country's development.

Exporting Environmental Degradation

• HDEs have reduced industrial pollution and have strict emissions regulations—but they import from overseas.
• This can be viewed as exporting environmental degradation: e.g., importing meat and timber from LDEs that deforest (e.g., Amazon).
• Deforestation is halted in many HDEs, but consumption drives deforestation elsewhere.

Not All HDEs Improve

• Not all highly developed economies reduce environmental degradation post-industrialisation.
• If the economy continues to grow, resources are still needed—often in greater amounts.
• HDEs tend to have highest CO₂ emissions—greater environmental degradation.

Conclusion

• The link between development and environmental degradation exists; the link between improved development and improving environment is tenuous.
• It only becomes viable with government policies and willingness to produce energy and goods in environmentally sustainable ways.
• There is no guarantee that economic growth will lead to environmental management.

• Sustainable development involves balancing population increase with conservation—examiners want to see you identify this.

• Reducing pressure on ecosystems to provide more maintains wellbeing—this is the core goal.

• EKC: Know the curve shape, but also its limitations—exporting degradation, multi-factorial causes, no guarantee of improvement.

• When discussing ecosystem services: use all four categories (provisioning, supporting, regulating, cultural) with examples.

• Positive vs negative feedback: Be able to explain both pathways of population increase on biodiversity.