Environmental Challenges and Sustainable Solutions
1. Environmental Sciences
Ecosystems consist of a physical space with environmental factors (temperature, salinity, humidity) and biotic components (living organisms). Humans extract resources from ecosystems, impacting the environment. Environmental sciences study ecosystems from various disciplines (geology, chemistry, biology, law, ethics, etc.).
2. Resource Overexploitation
Natural resources are everything humanity uses from nature. Resources can be non-renewable (limited quantities, e.g., oil), renewable (not exhausted, e.g., wind), and potentially renewable (exhausted if overused, e.g., fish). The population explosion, with virtually unlimited growth, strains limited resources.
3. Sustainable Development
Sustainable development meets present needs without compromising future generations. It balances economic, ecological, and social factors.
3.1 Ecological Footprint
Carrying Capacity: An ecosystem’s capacity to sustain life. It depends on many factors and is difficult to calculate for complex systems like Earth.
Ecological Footprint: Land needed to produce resources and assimilate waste. Expressed in hectares per person (U.S.: 10 vs. India: 0.8). An estimated 1.5 Earths are needed to secure humanity’s future.
3.2 Sustainable Development Principles
- Sustainable Gathering and Extraction: Extraction rate should be less than or equal to the regeneration rate.
- Sustainable Drainage: Extraction rate should equal the creation rate of renewable substitutes.
- Sustainable Emission: Waste emission rates must be at or below the ecosystem’s capacity.
- Zero Emissions: Reduce pollutant emissions to zero.
- Sustainable Integration: Urban settlements must not exceed the territory’s carrying capacity.
- Sustainable Technology Selection: Encourage efficient technology use.
- Precautionary Principle: Use models to avoid risks and ecological disasters.
4. Water as a Resource
Water is a limited renewable resource due to unequal distribution and freshwater scarcity. Freshwater scarcity is caused by population growth, urban development, increased agricultural and industrial activities, pollution, and deforestation. Water usage: agriculture and livestock (70%), industrial (22%), and domestic (8%). Overexploitation occurs when consumption exceeds renewal, leading to declining water stocks, especially groundwater.
4.1 Water Planning
Water planning involves cost-saving, technical, and policy measures.
Cost-Saving Measures: Reduce agricultural use (improve irrigation, promote traditional crops), industrial use (promote recycling, prevent pollution), and urban use (purify and reuse wastewater, promote environmental education, price water appropriately).
Technical Measures: Construct dams, reservoirs, and desalination plants, and carry out water transfers (expensive, last resort, environmental impact).
Policy Measures: Develop laws and agreements (e.g., International Conference on Water and Environment – Dublin, 1992).
5. Biosphere Resources
The biosphere is the collection of Earth’s ecosystems. Biosphere resources include biodiversity, soil, crops, livestock, forestry, and fishing.
- Biodiversity: Variety of organisms, providing food and raw materials.
- Soil: Important for agriculture, influenced by farming methods.
- Agricultural and Livestock Resources: Use soil, water, and biodiversity. Intensive agriculture causes environmental problems from resource overexploitation. Organic farming uses natural resources without synthetic chemicals or GMOs, maintaining soil fertility and aligning with sustainable development. Livestock farming involves raising animals outdoors with natural feed. Disadvantage: higher product costs.
- Fisheries: Overexploited due to high demand and intensive fishing. Aquaculture farms aquatic organisms, replicating natural environments.
- Forest Resources: Forests provide wood, oils, gums, resins, medicines, and food (cocoa, coffee). Essential for biosphere maintenance.
6. Mineral Resources
Mineral resources are non-renewable on a human timescale due to slow formation. Excessive consumption can lead to exhaustion.
7. Energy Resources
The most used energy sources are oil, coal, natural gas, nuclear energy, and hydropower. Only hydropower uses a renewable resource (water). Increased energy consumption necessitates alternatives.
7.1 Conventional Energies
Fossil fuels, nuclear fission, and hydropower.
Fossil Energy: Formed from organic matter accumulation (coal, oil, and natural gas). Highly polluting, generating greenhouse gases and particles.
Nuclear Fission: Uranium fission is common. Problems: waste storage and accidents.
Hydropower: Harnesses water energy. Non-polluting but requires infrastructure, altering ecosystems. Small hydropower has less impact.
7.2 Alternative Energy
Solar, wind, biomass, geothermal, tidal, and hydrogen.
8. Think Globally, Act Locally
Political Measures: Summits and treaties (e.g., Earth Summit, Rio de Janeiro, 1992).
Social Measures: Local actions to save energy, reduce resource production, and promote reuse and recycling.
9. Risks, Catastrophes, and Disasters
Natural Risk: Natural process threatening human life or property (volcanoes, earthquakes, tsunamis, diapirs, dune movements, climatic events).
Natural Catastrophe: Disruptive effect of an extraordinary natural phenomenon.
Natural Disaster: Large-scale catastrophe requiring outside help. Human activity can intensify effects.
9.1 Human Factors
- Uncontrolled population growth leads to unsuitable building locations.
- Global warming from pollution causes undesirable climate and weather phenomena.
- Deforestation increases erosion and flood risk.
- Poverty hinders disaster response.
10. Risk Analysis and Planning
10.1 Risk Analysis Factors
- Hazard (P): Probability of a damaging phenomenon within a specific time.
- Vulnerability (V): Damage from losses (0 = no damage, 1 = total loss).
- Exposure (E): Persons or property exposed to risk.
Risk Assessment (R) = P x V x E
Risk Planning: Prediction and prevention.
Prediction: Develop risk maps.
Prevention: Structural (e.g., earthquake-resistant buildings) and non-structural (e.g., evacuation plans) measures.
11. Volcanic Risk
Factors: eruption type, affected population, and risks (toxic gases, mudflows).
Eruption types: Hawaiian, Strombolian, Vulcanian, Plinian.
Planning: Prediction (volcano monitoring, precursor study), prevention (restrict settlements, shelters, evacuation plans, sloped roofs).
12. Seismic Risk
Earthquake effects depend on magnitude, focal depth, ground materials, and building characteristics.
Seismic Cycle: Inactivity, small earthquakes, foreshocks, main quake, aftershocks.
Planning: Prediction (long-term probability), prevention (structural and non-structural measures), education for risk.
13. Tsunamis
Giant waves caused by earthquakes, eruptions, or other phenomena. Detection by tide gauges and tsunameters allows evacuation.
14. Salt Diapirs
Rising salt masses causing unstable ground. Prevention: avoid water infiltration, inject solid materials.
15. Subsidence
Abrupt collapse or slow subsidence. Prediction and prevention: geophysical maps, building codes.
16. Expansive Soils
Soils (e.g., clays) that change volume quickly, causing building settlement issues.
17. Dune Movements
Sand invasion. Prevention: barriers, revegetation.
18. Landslides
Gravity-driven material movements. Causes: natural (slope, terrain, seismic activity, water saturation) and human-induced (slope changes, deforestation, urbanization). Types: rock falls, landslides, avalanches, flows. Prediction: slope observation. Prevention: containment measures, drainage, revegetation.
19. Climate and Weather Risks
Tropical Cyclone: Tropical storm rotating around a low-pressure area.
Hurricane: Tropical storm with winds over 118 km/h.
Typhoon: Hurricane in the Indian and Pacific Oceans.
Tornado: Rotating funnel cloud.
Prediction: Satellites.
19.1 Cold Drop
Weather situation in Spain with heavy rains and flooding.
19.2 Floods
Destructive hazard. Causes: heavy rain, sustained precipitation, river overflow, dam destruction, sea level rise, tsunamis, human activities. Danger depends on stream energy. Prediction: forecasting, risk mapping. Prevention: structural (dams, reforestation, channel capacity increase) and non-structural measures.
20. Cosmic Risk
Meteor, asteroid, or comet impact. Low probability but potentially catastrophic consequences.