Environmental Issues and Sustainability
What is Pollution?
Pollution is a disturbance of the environment caused by physical agents (such as temperature), chemical agents (like heavy metals in water), or biological agents (e.g., sewage), present in sufficient concentrations and in specific locations. It stems from human actions such as increased waste, biodiversity loss, desertification, and climate change. Pollution can be natural or anthropogenic (caused by humans).
Explain the Phrase “Polluter Pays”
This principle means that the polluter should bear the costs of implementing appropriate technologies to reduce pollution. However, some polluters currently prefer to pay fines due to their lower cost.
Why Do Multinationals Choose Countries with Minimal Environmental Regulations?
Multinationals often choose countries with lax environmental regulations to reduce costs and increase profits. These locations not only offer cheap labor but also minimal or no environmental costs associated with waste treatment, depending on the stringency of the regulations.
What is the Atmosphere?
The atmosphere is a thin gaseous envelope surrounding Earth. Its composition varies with altitude and consists of several layers. The troposphere, extending approximately 10km, is the lowest layer. The atmosphere protects us by absorbing ultraviolet radiation, reducing temperature differences between day and night, and acting as a shield against meteorites. The largest source of air pollution is the use of fossil fuels like petroleum, coal, and natural gas.
What are the Major Types of Air Pollution?
Major air pollutants include:
- CO (carbon monoxide) from hydrocarbon and biomass combustion
- CO2 (carbon dioxide)
- SO2 (sulfur dioxide)
- NH3 (ammonia)
- Oxides of N2 (nitrogen oxides) from hydrocarbon combustion
- CH4 (methane) from fuel extraction and waste emissions
- SH2 (hydrogen sulfide) from paper industries and refineries
- CH3Br (methyl bromide) from fumigation
- HCl (hydrogen chloride) from coal and plastic combustion
Explain the Consequences of Air Pollution, Acid Rain, and Photochemical Smog
Burning fossil fuels generates large amounts of sulfur and nitrogen oxides. These emissions contribute to chemical processes that produce acidic compounds, which precipitate as acid rain. Photochemical smog (a mix of smoke and fog) occurs in urban areas, which often act as heat islands, trapping pollutants and preventing their dilution.
What is Ozone?
The ozone layer is located in the upper atmosphere, between 30 and 50km altitude, and is rich in ozone. It protects the planet from harmful ultraviolet (UV) radiation, which can cause skin cancer and alter cellular DNA. Substances like CFCs (chlorofluorocarbons), used in refrigerants and aerosol cans, damage the ozone layer and contribute to the greenhouse effect by trapping heat.
Where Does Water Pollution Come From?
Water pollution originates from organic and chemical waste (including livestock and agricultural waste), sewage, and industrial discharge.
List and Explain the Types of Water Pollutants
- Nutrients (organic matter): Essential for aquatic plant growth, but excessive amounts can lead to oxygen depletion.
- Waste with oxygen requirement: Substances that consume oxygen during oxidation, depriving the water of it.
- Pathogens (bacteria, viruses): Can enter water through organic waste.
- Heavy metals: Highly toxic in large quantities and can enter the food chain.
- Organic compounds (pesticides, plastics, VOCs):
- Thermal pollution: Water used as a coolant in industrial processes increases water temperature, reducing oxygen levels.
- Sediment or suspended matter: Insoluble particles from erosion that reduce light penetration.
Difference Between Desert and Desertification
A desert is infertile land. Desertification is the process of ecological degradation by which soil becomes unproductive, loses its properties, and develops desert-like conditions. Desertification is driven by human activities like fires and logging, as well as factors such as overgrazing, chemical degradation, inappropriate agricultural practices, deforestation, soil compaction, water overexploitation, and urbanization.
Where is Desertification Most Prevalent? What are its Consequences?
The African continent has the highest incidence and risk of desertification. Consequences include water shortages, increased fire risk, epidemics, poverty, famine, and social unrest.
What are the Causes of Modern Extinctions?
Modern extinctions are primarily caused by habitat loss or degradation (deforestation, pollution, climate change) and predation by invasive species.
What Does the Word Biodiversity Mean?
Biodiversity encompasses the variety of life on Earth, including the number of species (around 1.5 million described), the diversity of ecosystems, the number of individuals within each species, and the genetic diversity within species. The Convention on Biological Diversity was established at the 1992 UN Conference on Environment and Development in Rio de Janeiro.
How Many Species Have Been Described? Extinction Rates?
Approximately 1.5 million species have been described. Over 150 species go extinct every day, and between 18,000 and 55,000 species go extinct annually.
What are the Benefits of Wild Plants and Algae?
Around 25% of drugs contain derivatives of wild plants. Algae are a potential food source for humans due to their low fat content and high protein, vitamin, and mineral content, which is particularly relevant given the increasing global population.
What is the Importance of Tropical Forests for Biodiversity?
Tropical forests are crucial for biodiversity, as they are estimated to house half of the Earth’s species. The biggest threat to these forests is uncontrolled deforestation driven by agricultural expansion, timber harvesting, livestock grazing, mining, housing development, and road construction.
Explain the State of Biodiversity in Spain
Spain has the greatest biodiversity in Europe, with approximately 55,000 species of fauna in the Iberian Peninsula, representing over 50% of the species in the European Union. The Canary Islands are particularly important for biodiversity. However, several endangered species exist in Spain, including the Iberian lynx, giant lizard, and monk seal. Spain also has the highest number of threatened vertebrates in Europe.
What is Waste? Explain the Types
Waste is any substance or object that the holder discards or intends to discard. Types of waste include agricultural and forestry waste (plants, leaves, twigs, sawdust), municipal solid waste, healthcare waste (medicines, plastics), industrial waste (often toxic), and radioactive waste (classified as high, medium, or low activity based on hazardousness).
Cite Two Reasons for the Increase in Waste. What is the Impact?
Two reasons for the increase in waste are the consumption habits of wealthy nations and the desire of developing nations to achieve similar lifestyles. Waste management is expensive and sometimes non-existent, leading some industrialized countries to export waste to developing countries, exploiting their needs and often weak environmental policies.
Explain the Difference Between Rich and Poor Countries in Relation to Waste Generation. Is Exporting Waste Ethical and Legal?
Rich countries’ societies promote overconsumption and a throwaway culture, generating vast amounts of waste. They often export waste to poorer countries to minimize management costs, taking advantage of their needs and often less stringent regulations. This practice is neither ethical nor legal.
Is the Global Climate Changing? What Facts Justify This?
Yes, the global climate is changing. Evidence includes more frequent extreme weather events like floods, heat waves, record temperatures, droughts, hurricanes, etc.
What is the Greenhouse Effect?
The greenhouse effect occurs when solar radiation penetrates the atmosphere and reaches the Earth’s surface. The Earth absorbs this radiation and emits some of it back as infrared radiation. Greenhouse gases trap this outgoing radiation, returning it to the Earth’s surface and causing warming. Human activities increase the concentration of these gases (primarily carbon dioxide, water vapor, methane, chlorofluorocarbons, and nitrous oxide), intensifying the greenhouse effect and disrupting the planet’s energy balance.
List Data Proving Global Warming. What are the Consequences?
Evidence for global warming includes:
- Eleven of the past twelve years are among the warmest on record.
- Projected temperature increases this century range from 1.8 to 4 degrees Celsius.
- Accelerated sea level rise.
- Shrinking glaciers in both hemispheres.
Consequences include increased drought and desertification, heavier rainfall leading to erosion and flooding, longer and more frequent heat waves, rising sea levels causing coastal flooding, more frequent extreme weather events, and negative impacts on human health.
What is the Kyoto Protocol?
The Kyoto Protocol is a UN agreement signed in Kyoto, Japan, in 1997. It aimed to reduce greenhouse gas emissions by 5.2% between 2008 and 2012 compared to 1990 levels. Spain is the EU country that deviates most from its commitment.