Environmental Science: Key Concepts and Definitions

Frontier Ethics vs. Environmental Ethics

Understanding the difference between frontier ethics and environmental ethics is crucial for evaluating human interactions with natural resources.

• Frontier Ethics: The view that natural resources are unlimited and humans should use them however they want.

• Environmental Ethics: The belief that people must care for the environment and use resources in a sustainable way.

• Shift in Ethics: The shift from frontier ethics to environmental ethics occurred because of damage caused by overusing resources, pollution, and habitat loss. Environmental ethics emphasizes the need to protect ecosystems for future generations.

Scientific Method and Related Terms

The scientific method is a systematic approach to research and experimentation in science.

• Scientific Method: A method of research with defined steps that include experiments and careful observation.

• Hypothesis: A proposed explanatory statement for a given natural phenomenon, that can be tested.

• Scientific Theory: A widely accepted, thoroughly tested and confirmed explanation for a set of observations or phenomena.

• Scientific Laws: Often in formulas, describe how elements of nature will behave under certain specific conditions, but they do not offer explanation for why they occur.

• Variables: The factors that can change in an experiment.

• Controls: Parts of the experiment that are kept constant to make results fair.

Global Environmental Issues

Several factors impact global environmental processes, including population growth, loss of biodiversity, deforestation, climate change, and resource depletion.

• Key Issues: Population growth, loss of biodiversity, deforestation, climate change, and resource depletion.

Elements, Compounds, and Building Blocks of Life

Understanding the basic units of matter is essential in environmental science.

• Elements: Pure substances made of one kind of atom. There are about 118 known elements.

• Compounds: Substances formed when two or more elements bond together. There are millions of known compounds.

• Building Blocks of Life: Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur are the main elements that make up living organisms.

Water and Its Importance

Water is a critical resource for life and environmental processes.

• Global Water Distribution: Only about 2.5% of Earth's water is freshwater, and less than 1% is accessible for human use.

• Water Scarcity: 25% of the world lacks safe drinking water, and about 40% lack proper sanitation.

Deforestation and Its Effects

Deforestation is the clearing of forests, often for human use, and has significant environmental impacts.

• Primary Reason: In the tropics, the main reason is clearing land for agriculture (especially cattle ranching and crops like soy or palm oil).

Energy Flow in Ecosystems

Energy flows through ecosystems via producers, consumers, and decomposers.

• Producers: Organisms (like plants) that make their own food from sunlight.

• Consumers: Organisms that eat other organisms for energy.

• Decomposers: Organisms (like fungi and bacteria) that break down dead matter.

• Energy Transfer: Only about 10% of energy passes from one level to the next.

Ocean Zones and Life

The ocean is divided into zones based on light, temperature, and nutrient availability.

• Photic Zone: Area near the surface with sunlight.

• Aphotic Zone: Deeper water with little or no light.

• Oceanic Zone: Open ocean, away from coast.

• Abyssal Zone: Very deep part of the ocean, dark and cold.

Biotic and Abiotic Factors

Biotic and abiotic factors influence ecosystems.

• Biotic Factors: Living parts of an environment (plants, animals, bacteria).

• Abiotic Factors: Nonliving parts of an environment (sunlight, soil, temperature, water).

Biodiversity and Conservation

Biodiversity refers to the variety of life in an area and is essential for ecosystem health.

• Preserving Biodiversity: Protect habitats, reduce pollution, recycle, support conservation programs, and practice sustainable resource use.

• Distinguishing Biomes: By climate (temperature, rainfall) and the types of plants and animals found there.

• Carrying Capacity: The maximum population size that an environment can sustain.

Survivorship Curves

Survivorship curves show how populations grow or decline over time and how survival rates differ among species.

• Type 1: Most individuals survive until old age (humans).

• Type 2: Constant death rates at all ages (birds).

• Type 3: High death rate early, but survivors live long (fish, plants).

Urbanization and Its Effects

Urbanization is the spread of cities into rural land, causing more traffic, pollution, habitat loss, and higher costs for infrastructure.

• Potential Consequences: Overcrowding, pollution, poor housing, unemployment, and increased demand for resources.

• Urban Blight: The decay of parts of a city, often characterized by abandoned buildings, crime, and poor infrastructure.

• Addressing Urban Blight: Redevelopment, community programs, and better public services.

Renewable and Nonrenewable Energy

Energy sources are classified as renewable or nonrenewable based on their availability and rate of replenishment.

• Renewable Energy: Comes from sources that can be replaced quickly. Examples: solar, wind, hydro, geothermal.

• Nonrenewable Energy: Limited resources that take millions of years to form. Examples: coal, oil, natural gas.

Nutrient Cycles

Nutrient cycles describe how elements move through the environment.

• Nitrogen Cycle: Nitrogen cycles in how bacteria convert nitrogen into forms plants can use.

• Carbon Cycle: Involves the burning of fossil fuels and ultimately causes climate change.

Species Interactions

Species interact in various ways, including mutualism, parasitism, and commensalism.

• Mutualism: Both benefit (bees and flowers).

• Parasitism: One benefits, the other is harmed (fleas on dogs).

• Commensalism: One benefits, the other is unaffected (barnacles on whales).

Population Growth and Curves

Population growth can be described by different curves and models.

• Exponential Growth: U-shaped curve, rapid increase in population.

• Logistic Growth: S-shaped curve, population growth slows as resources become limited.

• Pyramid Shape: Population profile of a developing country, wide base, narrow top.

• Doubling Time Formula: The "Rule of 70" estimates the number of years for a population to double.

Formula:

Additional info:

• Some content inferred from context and standard environmental science curriculum.