Question 1: With reference to our planet (Earth), what is the meaning of the word “environment”?
Answer: Environment is the totality of surroundings (or global ecosystem) which consists of all living and non-living things (soil, rocks, rivers, seas, air, gases, plants, trees, animals, etc.)—or, as the famous physicist Albert Einstein defined it, “The environment is everything that isn’t me [or us: the people]”.
Question 2: What are the main objectives of environmental science?
Answer: The main objectives of environmental science are:
- to learn how nature works
- to understand how people interact with the environment
- to find ways to handle environmental problems so that people can live more sustainably.
Question 3: What is ecology?
Answer: Ecology can be defined as a branch of science that studies how organisms or living things interact with one another and their environment. It can also be defined as the totality of the patterns of relationships between organisms and their environment.
Question 4: What is an ecosystem?
Answer: An ecosystem is a set of living organisms within a particular area that interact with each other and their environment which contains non-living things, matter and energy. Typically, all living organisms in an ecosystem interact with one another, with solar energy, and with all non-living things within their ecosystem’s land, water and air.
Question 5: What is environmentalism?
Answer: Environmentalism can be defined as an activity or movement committed to protecting all life-supporting systems from pollution and destruction. Environmentalism is mainly practiced in political and ethical spheres more than it is practiced in science.
Question 6: What are the 3 major things that the Earth’s long-term environmental sustainability depend on?
Answer: The Earth’s long-term environmental sustainability depends on the following:
- Solar energy: this is the energy from the sun which the Earth uses to support photosynthesis for plants to grow and provide nutrients needed by living organisms to stay alive and reproduce. Without solar energy, there wouldn’t be any plants, food and animals
- Chemical cycling: also known as nutrient cycling, refers to recycling and circulation of nutrients within the environment (land, air and water) for growth and sustenance of all forms of life. Without chemical cycling, there wouldn’t be fresh air, fresh water and renewed soil—implying that there wouldn’t be any food, and any life
- Biodiversity: also known as “biological diversity”, refers to the wide variety of organisms, the natural systems (land, air and water bodies) in which they live and the free services they provide, such as purification of water and air, and renewal of topsoil. Without biodiversity, most forms of life wouldn’t exist.
Question 7: What are natural resources?
Answer: Natural resources are mineral deposits, materials, waterpower, resources or energy supplied by nature.
Question 8: What are natural services?
Answer: Natural services are processes (such as purification of air, renewal of water and topsoil, etc., in nature) that efficiently renew all natural resources and support all forms of life.
Question 9: What is natural capital?
Answer: Natural capital is the totality of natural resources and natural services that keep human beings, animals, plants and other forms of life alive and supports their existence. Natural capital can sustainably and continuously support the wide diversity of species, populations and nations if managed properly and not spent too quickly.
Question 10: What are renewable resources?
Answer: Renewable resources are natural resources that are replenished by natural processes at a rate comparable to their rates of consumption or usage by humans, animals and natural processes. They can also be defined as resources that take anywhere from several days to a few hundred years to be replenished through natural processes, as long as they aren’t used up faster than nature can renew them.
Question 11: List some examples of renewable resources.
Answer: Examples of renewable resources include forests, plants, grasslands, populations of fishes, freshwater, fresh air, fertile topsoil, etc.
Question 12: What are non-renewable resources?
Answer: Non-renewable resources are natural resources that can’t be replenished in our lifetimes, or in very many lifetimes. They can also be defined as natural resources that can be renewed by geological processes after tens of thousands, millions or billions of years.
Question 13: List some examples of non-renewable resources.
Answer: Examples of non-renewable resources include fossil fuels: coal, petroleum, and natural gas; minerals and metals that lie deep in the Earth: iron, silver and gold, silver, and iron, fossil fuel, aluminium, etc.; nuclear materials such as Uranium, etc.
Question 14: Under which conditions would human activities deplete natural capital beyond sustainable limits?
Answer: Human activities would deplete natural capital beyond sustainable limits if human activities use up resources faster than nature can restore them; also, when natural components/systems (water, water flow, air, air flow, land, etc.) are overloaded with pollution and wastes beyond nature’s capacity to purify and renew them.
Question 15: Give examples of human activities that deplete natural capital beyond sustainable limits.
Answer: Examples of human activities that deplete natural capital beyond sustainable limits or make natural capital unsustainable, include:
- Cutting down of trees and clearing of matured forests much faster than nature can regrow them
- Eroding of topsoil much faster than nature can renew it through nutrient cycling (or recycling)
- Removal of groundwater much faster than nature can replenish it
- Disposal of polluted wastewater, chemicals, solid and animal wastes into oceans, rivers and lakes much faster than nature can purify these bodies of water.
Question 16: Give examples of renewable resources that could be used much more in order to reduce dependence on non-renewable resources like fossil fuel and coal which are rapidly diminishing day after day.
Answer: Examples of renewable resources that could be used in order to reduce dependence on fossil fuel and coal include wind, solar energy, flowing water, and heat in the interior part of the earth.
Question 17: What is recycling?
Answer: Recycling is the act of processing used, discarded or abandoned waste materials into new materials or products. For example, pieces of steel and aluminium can be melted to form new cans or products. On the other hand, resources such as fossil fuel and coal cannot be recycled once they undergo combustion.
Question 18: Define pollution.
Answer: Pollution can be defined as any undesirable, unattractive and unwanted state in which the natural environment is contaminated with harmful substances as a result of human and animal activities.
Question 19: What are point sources (PS) of pollution?
Answer: Point sources of pollution are individual, single and easily identifiable sources of pollution, or any sources of pollution that originate from concentrated areas or identifiable points such as discharge points on septic tanks, open ends of wastewater discharge pipes from breweries, chimneys of incinerators, effluent wastewater pipes of abattoirs, and exhaust pipes of automobiles.
Question 20: What are non-point sources (NPS) of pollution?
Answer: Non-point sources of pollution are sources of pollution that do not originate from a single source, an identifiable point, or concentrated area. Non-point sources of pollution are often called “diffuse” pollution because they cover a wide area and cannot be traced to a specific point or concentrated area. Examples of non-point sources of pollution include areas containing pesticides blown from land into air, runoff of fertilizers/chemicals used on farms, and trash carried by stormwater from land into streams and lakes.