1.1.2 environment and resources

What are the 4 types of ecosystem services, and what does each provide?

PRCS

• P — Provisioning: direct products → food, water, timber, fuel, medicines

• R — Regulating: regulate natural processes → climate regulation, carbon sequestration, purification, pollination, flood/pest control

• C — Cultural: non-material benefits → recreation, ecotourism, spiritual/heritage, education

• S — Supporting: processes underpinning other services → plant production, soil processes, water storage, groundwater recharge

How does overfishing in the South China Sea show that human activity can reduce provisioning services?

South China Sea (SCS):

• Only 2.5% of global ocean area, but produces 12% of world's fish catch

• 15–56% of animal protein consumed in SE Asia comes from the sea

• Half of world's 3.2m registered fishing boats operate there

• Since 2000: catch rates ↓ 70%, large fish stocks ↓ 90%

Causes = Demand ↑ + fishing Technology improves + Political issues

→ extraction > fish regeneration → ↓ provisioning service.

What 3 major human activities affect ecosystem services?

DPI

• D — Destruction of habitats/deforestation

• P — Pollution

• I — Invasive species

These can reduce biodiversity and damage multiple ecosystem services simultaneously.

How does habitat destruction/deforestation affect ecosystem services?

Habitat loss → ↓ space for species to survive/reproduce → ↓ biodiversity.

Impacts:

• Provisioning: ↓ timber, medicines, genetic resources

• Regulating: ↓ carbon sequestration + flood/climate regulation

• Cultural: ↓ wildlife/ecotourism value

How do the Amazon and Sumatra demonstrate impacts of deforestation?

Amazon: deforestation → habitat/biodiversity loss + ↓ carbon sink/climate regulation + loss of potential medicinal/genetic resources.

Sumatra:

• ~12m ha forest cleared in 22 years

• ~50% forest loss

• ~201 mammal + 580 bird species

• Threatens critically endangered Sumatran rhinos/tigers

→ One environmental change can damage multiple ecosystem services.

How does landfill pollution affect climate and aquatic ecosystems?

Two processes:

Climate:
Organic waste decomposes → methane → potent GHG → climate change.

Water:
Landfill leaks → leachate → ammonia → nitrate → ↑ plant/algal growth → eutrophication → ↓ dissolved O₂ → dead zones → aquatic deaths.

How does the Deepwater Horizon oil spill demonstrate impacts of pollution?

Gulf of Mexico, 2010: Deepwater Horizon oil rig exploded → major oil spill → marine contamination → >2 million animals died.

→ Pollution damages biodiversity + ecosystem services.

How does water hyacinth in the Mekong Delta show the impacts of invasive species?

Water hyacinth can double its population in 2 weeks.

Rapid growth → dense surface mats → ↓ sunlight + dissolved O₂ → aquatic ecosystem imbalance → ↓ fish → harms fishermen.

Also:

• Blocks rivers/canals → flooding

• ↓ rice yields

• Creates mosquito breeding habitat

→ Environmental + economic + social impacts.

What is the difference between non-renewable, renewable and perpetual resources?

• Non-renewable: finite; cannot regenerate at a rate comparable to consumption → fossil fuels/minerals

• Renewable: naturally replenished → crops, fisheries, water, forests

• Perpetual: continuously renewed and generally cannot be exhausted → WWSTG: Wind, Waves, Solar, Tidal, Geothermal

Why can a renewable resource still become depleted?

Renewable ≠ unlimited.

Rate of use > rate of natural replenishment (regenerative capacity)
→ resource stock declines → depletion.

Therefore, sustainable resource management requires exploitation ≤ regenerative capacity.

How does groundwater extraction in Jakarta demonstrate resource over-exploitation?

Jakarta:

• Subsiding ~10 cm/year

• Parts of North Jakarta sank 2.5 m in 10 years

• Almost ½ the city below sea level

• 40% residents lack piped water

Lack of piped water → excessive/illegal groundwater extraction → aquifer emptied → ground compacts/subsides → ↑ flood vulnerability.

What are the 4 categories of resource reserves?

PCHS

• P — Proven: known + economically recoverable with current technology

• C — Conditional: known but currently uneconomic/unfeasible

• H — Hypothetical: undiscovered but may exist in known mining/geological areas

• S — Speculative: may exist in new/unanticipated areas

Availability can change with technology, costs, politics and environmental considerations.

What are the 4 main forms of resource scarcity?

PGER

• P — Physical: actual exhaustion of resources

• G — Geopolitical: political control/restriction of resources

• E — Economic: resources exist but countries/people cannot afford them; rich economies may outbid poor

• R — Renewable/environmental: exploitation or pollution exceeds regenerative/absorptive capacity

What determines whether a population is underpopulated, optimum or overpopulated?

It depends on population relative to available/accessed resources and resulting SOL, NOT simply population density.

• Underpopulation: too few people to efficiently utilise resources → ↑ population may ↑ SOL

• Optimum: resource utilisation produces maximum SOL

• Overpopulation: population exceeds accessible resources → ↓ SOL

Examples: Canada = underpopulation; Bangladesh = overpopulation.

What is Malthus' theory of population and resources?

Pessimistic view:

Population grows geometrically/exponentially:
1, 2, 4, 8, 16

Food/resources grow arithmetically:
1, 2, 3, 4, 5

→ population eventually exceeds food supply/carrying capacity → shortages → checks reduce population.

Carrying capacity: largest population an area can support without environmental degradation.

What are Malthus' positive and preventive checks?

Positive/Natural checks → ↑ death rate

• Famine

• Disease/plague

• War

Preventive/Negative checks → ↓ birth rate

• Delayed marriage

• Fewer children

• Abstinence

• Contraception

→ prevent or correct population from exceeding resources.

To what extent is Malthus' theory applicable?

More applicable to:

• Pre-industrial Europe with low technology

• Some very poor regions, e.g. Sub-Saharan Africa

BUT major limitations = TPTG

• T — Technology: Green Revolution, HYVs + pesticides ↑ food production

• P — People: ↑ population can mean ↑ labour + innovation

• T — Transition: population growth also resulted from falling death rates, not only high births

• G — Global trade: countries can import resources

Singapore: low domestic carrying capacity but can import food, avoiding famine.

What is Boserup's theory of population and resources?

Optimistic / Anti-Malthusian: "Necessity is the mother of invention."

Population ↑
→ pressure/resource scarcity
→ innovation + agricultural intensification
→ ↑ resource productivity/supply
→ ↑ carrying capacity/SOL.

Thus, unlike Malthus, population pressure stimulates solutions rather than inevitably causing catastrophe.

What examples support Boserup's view that innovation can overcome resource pressure?

• Agriculture: HYVs, hydroponics/intensification

• Energy: geothermal, nuclear, wind, hydroelectric, biofuel

• Food: insect-/plant-based alternatives

• Water: desalination + NEWater

• More people → more labour, ideas, inventions and R&D

What are the main limitations of Boserup's theory?

GELD

• G — Globalisation: ignores migration/labour mobility

• E — Economic motives: innovation may be driven by agribusiness profit rather than population need

• L — Limits: finite limit to how many new resources/efficiency gains technology can create

• D — Degradation: technology may itself damage the resource base

Examples:

• Agriculture → deforestation + soil exhaustion

• Fracking → wastewater, methane, toxic air pollutants + habitat degradation

What is the key difference between Malthus and Boserup?

Malthus:
Population ↑ → demand > resources → scarcity → population checks
= pessimistic

Boserup:
Population ↑ → resource pressure → innovation/intensification → ↑ resources/carrying capacity
= optimistic

Key disagreement = whether technology/innovation can overcome resource limits.

What important limitation do BOTH Malthus and Boserup share?

Both underplay unequal access/distribution of resources across space.

Food insecurity ≠ necessarily insufficient global food.

It can result from:

• Poverty

• Unequal access

• Poor governance

• Unfair trade arrangements

→ Resource scarcity can be economic/political rather than physical.