Environmental Issues and Sustainable Development

Environmental Issues - Indirect Drivers

• Human population growth
• Dependence on fossil fuels (transport, electricity, industry)
• Consumerism/materialism (unsustainable production & consumption)
• Poverty and conflict
• Degradation of common property (air, sea, fish, land, forests)

Sustainable Development

• Improvement in quality of life for its people
• Development that meets the needs of the present without compromising the ability of future generations to meet their own needs (Brundtland report 1987)
• Three interconnected pillars:
  • Social progress (justice and quality of life)
  • Economic growth (wealth generation)
  • Environmental responsibility (care for the planet)

Sustainable Development Goals (SDGs)

• United Nations adopted Agenda 2030, based on 17 SDGs
• Aim to achieve more sustainable development
• Improve people's quality of life, while protecting climate and biodiversity

Natural Resources

• Any substance, form of energy, or object found in the natural environment that is useful to any living organism (air, water, soil)
• Biotic: Living resources (crops, fish, trees)
• Abiotic: Non-living resources (metals, fossil fuels, wind, soil, flowing water)
• Renewable: Resources that can replenish themselves (sun, wind, water, biotic resources)
• Non-renewable: Resources that don't replenish on human timescales (fossil fuels, metals, minerals)

Earth's Structure

• Crust: Outermost layer, divided into continental and oceanic crusts.
  • Continental crust: thicker, less dense, made primarily of granite
  • Oceanic crust: thinner, denser, made primarily of basalt
• Mantle: Thick layer below the crust, mainly comprised of silicon and magnesium oxides.
  • Upper mantle: solid, contains the asthenosphere (semi-molten material)
  • Lower mantle: solid despite high temperatures due to high pressures
• Core: Innermost layer, two parts.
  • Outer core: molten iron and nickel; controls Earth's magnetic field.
  • Inner core: solid iron and nickel; hottest part of Earth.

Plate Tectonics

• Theory explaining natural phenomena such as earthquakes, volcanic eruptions, mountain building, and ocean trenches.
• Lithosphere is divided into seven major and several minor tectonic plates.
• Plates are in slow, continuous movement due to convection currents in the asthenosphere.
• Plate boundaries (margins): where plates interact – divergent, convergent, and conservative.

Rocks

• Earth's lithosphere is made from rocks.
• Rocks are categorized into three main classes: igneous, sedimentary, and metamorphic.
• Igneous: Formed from solidified magma (basalts and granites).
• Sedimentary: Formed by lithification of sediments (e.g., chalk, limestone).
• Metamorphic: Formed from other rocks due to heat and pressure.

Weathering and Erosion

• Weathering: Gradual breakdown of rocks and soil. Can be chemical, physical, or biological.
• Erosion: Removal of weathered particles by wind or water.
• Main types of weathering processes include chemical, physical, and biological.

Biogenic Sedimentation

• Sedimentation made up of hard remains of dead organisms.
• Examples: Plankton, coralline algae, seashells, crabs.

The Rock Cycle

• Rocks are neither created nor destroyed, transformed over long periods of time by physical and chemical processes.
• Igneous, sedimentary, and metamorphic rocks are involved in the rock cycle.

Soil

• Soil is a natural resource that supports life and agriculture.
• A complex mixture of weathered rock, water, air, nutrients, and living organisms.
• Five main soil horizons are commonly recognised: O (humus), A (topsoil), B (subsoil), C (parent material), and R (bedrock).

Soil Degradation

• Loss of soil through the action of wind or water.
• Various practices like overgrazing, deforestation, and overcultivation can lead to soil erosion.
• Overgrazing: leads to soil exposed and susceptible to erosion
• Deforestation: takes away tree cover.
• Overcultivation: leads to land degradation
• Gullying: a type of erosion.
• Silting of water bodies: occurs when soil is carried into rivers, lakes or reservoirs.
• Desertification: transformation of habitable land into a desert.

Soil Fertility

• Depends on minerals present, water content, and aeration levels.

Agriculture’s Role in Environmental Impacts

• Soil: Overgrazing, deforestation, and overcultivation.
• Water: Leachate and runoff from agricultural lands, containing animal waste and fertilizers.
• Air: Emissions from livestock (methane), fertilizers (nitrous oxide), and burning crop residues.
• Biodiversity: Clearing of forests for agriculture, use of intensive monoculture farming, pesticide use.
• GMOs: Potential for impacting traditional crop varieties.

Agriculture and Water Quality

• Leaching of fertilizers (nitrates and phosphates) and/or animal waste.
• Eutrophication: Increased nutrient levels in water, leading to algal blooms and low oxygen levels, harmful to other aquatic life.

Agriculture and Groundwater

• Leaching of nitrates from fertilizers.
• Nitrate contamination: can pose health risks.

Sustainable Management of Resources

• Quotas: Limits on harvesting.
• Protected habitats: setting aside areas for species protection.
• Monitoring & enforcement: strict regulations on specific species
• Restoration of degraded habitats.
• Afforestation. Improved practices for re-growing forests
• Aquaculture: Farming in water, and substituting less threatened species.
• Resource substitution: replacing threatened resources with less endangered ones, such as reducing the consumption of rarer fish.

Energy Sources

• Renewable: Sunlight, wind, water, geothermal, biomass
• Non-renewable: Fossil fuels (crude oil, natural gas, coal), nuclear fuels