Global Environmental Challenges: Pollution, Resources, and Biodiversity Loss

Posted on Sep 28, 2025 in Geology

Environmental Impacts of Resource Use

Living Resources and Their Exploitation

Livestock and Intensive Farming Impacts

Intensive livestock farming presents major environmental problems, including the use of treated feed, reduction in biodiversity, and significant pollution caused by slurry (manure and excrements).

Marine Resources and Fishing Challenges

Environmental problems related to fishing include:

  • Fishing overexploitation.
  • Use of non-selective nets and drag fishing techniques.
  • Impacts from climate change.
  • Significant reduction in biodiversity.

Solutions for Sustainable Fishing

Potential solutions include:

  • Reconversion of the fishing fleet.
  • Restrictive regulations.
  • Biological rest periods and creation of marine reserves.
  • Preventing the consumption of juvenile fish (fry).
  • Promoting aquaculture.

Understanding Environmental Pollution

Air Pollution: Definition and Types

Air pollution is the presence of substances and forms of energy in the air that alter its quality, posing risk, damage, or serious nuisance to people and the wider community. Air pollution is often caused by a combined force of several pollutants, not just a single source.

Primary and Secondary Pollutants

  • Primary Pollutants: Released directly from the source into the atmosphere (e.g., volcanic emissions).
  • Secondary Pollutants: Formed when primary pollutants evolve and react chemically in the atmosphere.

Consequences of Air Pollution

Acid Rain Formation and Effects

Oxides of nitrogen and sulfur produce sulfuric and nitric acid, which precipitate as rain. This causes environmental surface damage, including forest loss and lake acidification.

Photochemical Smog in Urban Areas

Photochemical smog occurs in urban areas where heat accumulation traps contaminants. Generated contaminants do not escape easily. Hydrocarbon oxides react with atmospheric oxygen and solar energy to produce ozone and other harmful products.

Ozone Layer Depletion and UV Radiation

The ozone layer acts as a shield against harmful ultraviolet (UV) radiation. CFCs (chlorofluorocarbons) destroy the ozone layer, allowing increased UV radiation to reach the surface, which leads to higher rates of skin cancer.

Note: CFCs, used in refrigerants and aerosol propellants, also contribute to the greenhouse effect and are controlled in many countries.

Water Pollution: Sources and Contaminants

Major Sources of Water Contamination

Sources of water pollution include:

  • Agricultural and livestock waste.
  • Sewage.
  • By-products from various types of industry.

Key Water Pollutants and Effects

Water pollutants include:

  • Nutrients (Eutrophication): Excessive nutrients cause aquatic plants (algae) to grow excessively. When they die due to lack of resources, they decompose, consuming oxygen and severely degrading water quality.
  • Waste requiring oxygen (BOD/COD).
  • Pathogens.
  • Salinity.
  • Heavy metals, leading to bioaccumulation and biomagnification.
  • Thermal pollution.
  • Organic compounds (e.g., oil spills).
  • Sediment or suspended matter.