Earth’s Resources and Pollution: A Comprehensive View
Natural Resources
Natural resources are materials found in the environment that are useful to humans. There are two main types:
- Non-renewable resources: These resources have geological origins and take thousands of years to regenerate, making them limited. Examples include land, fossil fuels, and minerals.
- Renewable resources: These resources are generated continuously and are not limited. Examples include solar energy, wind energy, and resources obtained from animals and plants.
Water Resources
Water is the most important natural resource for human beings; our existence depends on it. Fresh water, primarily from the evaporation of seawater, represents only 2.5% of the total water on Earth. The water cycle allows for its reuse. Contaminating water sources leads to significant water loss.
Water Contamination
Water is polluted when it contains toxic waste that endangers human health. There are three main sources of water contamination:
- Domestic: From personal care and household cleaning.
- Agricultural and livestock: Contamination from fertilizers and pesticides.
- Industrial: Alteration by waste from various sources, such as heavy metals.
Water Purification
To make water drinkable, it undergoes processes in treatment plants. There are two main types of processes:
- Physical processes: Such as sedimentation, filtering, or decanting to remove organic matter and particles that cause the dark color of untreated water.
- Chemical processes: Eliminate other elements from the water using mineral salts that precipitate when combined with these elements. Microorganisms are then removed by subjecting the water to ozone or ultraviolet radiation. Chlorination is a cheap and effective method, but it leaves the water with a chlorine taste.
Wastewater Treatment
Water used in households, industries, and other applications should be treated to remove spills and contaminants. There are four main steps:
- Pretreatment: Removes large solids in suspension or floating (sticks, plastic, leaves).
- Primary treatment: Separation of solids not removed during pretreatment by physicochemical processes such as flotation, sedimentation, and coagulation. This takes place in a decanting tank with chemicals.
- Secondary treatment: Settling and biological processes. The water is placed in large tanks under aerobic conditions, forming a mass of sludge that is removed by decanting.
- Tertiary treatment: Elimination of minerals, viruses, heavy metals, and organic matter, often combining the previous three processes.
Pollution
Pollution is the increase or appearance of harmful substances, affecting the activity and survival of organisms and human beings. There are two main types:
- Chemical pollution: The presence of unusual chemical compounds, such as non-degradable pesticides, or common compounds in excessive amounts, such as CO2.
- Physical contamination: Changes in the physical characteristics of the atmosphere, soil, or water, including noise, thermal, or radioactive pollution.
The Greenhouse Effect
The greenhouse effect is the atmosphere’s role in warming the Earth’s surface. Gases like CO2 allow sunlight to pass through but retain heat radiation, preventing the Earth from cooling. The increasing concentration of CO2, a major greenhouse gas, is due to:
- Increased industrialization.
- Heating systems, vehicles, and power plants that use fossil fuels.
- Deforestation.
Climate Change
Several forecasts regarding climate change include:
- Sea level rise due to melting ice and disappearing glaciers.
- Disappearance of farmland near coastlines.
- Changes in rainfall patterns, with increased rainfall on the coast and decreased rainfall on islands.
- Changes in vegetation distribution, decreasing arable areas due to drought and desertification.
- Emergence of tropical diseases, such as malaria and cholera, in areas where they don’t currently exist, like Europe.