evr 1001- key themes of environmental science

pop a perc and a black out

6 Themes of Environmental Science

1. Human Population Growth

2. Sustainability and Carrying Capacity

3. A Global Perspective

4. An Urban World

5. People and Nature

6. Science and Values

1 billion; 13

We are currently increasing at a rate of ___ people every ___ years

Malthusian (Exponential Population Growth)

Population growth in the absence of resource limitations; growth is proportional to population

True

T/F: Exponential population growth is equal to doubling at fixed intervals

Carrying Capacity

Exponential population growth keeps growing until they reach the ____ of their environment

Carrying Capacity (in Human Population Growth)

The number of people, other than living organisms or crops that region can support

1. Population Stabilizes

2. Overshoot and Crash

3. Export emigrants

What 3 options can happen when a population reaches the Carrying Capacity?

Population Stabilizes; After a steady increase in population, once it reaches the Carrying Capacity, the growth stabilizes

_{What does this graph represent in relation to Carrying Capacity?}

Overshoot and Crash; Results in degrading the environment, increase massively then decline due to lack of resources and overpopulation

_{What does this graph represent in relation to Carrying Capacity?}

Export Emigrants; people leave

What is the third option for when the population reaches Carrying Capacity?

Carrying Capacity (in Sustainability)

The max number of plants, animals, bacteria, etc. that an environment can sustain

Depends on health of ecosystem, per capita resource utilization (how many resources each individual uses), quality of life, technology

Why is Carrying Capacity not constant?

1. Sustainability of a Resource

2. Sustainability of an Ecosystem

2 Types of Sustainability

Sustainability of a Resource

Harvest/take no more than is replaced

1. Human stressors 

2. Natural disturbances/disasters

3. Ecosystem resilience

4. Biodiversity

Sustainability of an Ecosystem depends on (4)

Populations without conflict, clean energy, planned use of renewable resources, using nonrenewable resources sparingly, political system that priotizes long-term prosperity > short-term gain

Achieving sustainability would include

A Global Perspective

A recent idea that Includes climate change and how humans significantly affect the environment; remote regions are connected by atmosphere and water

Exposed the chemical “DDT“

What is the significance of “Silent Spring” by Rachel Carson (1962)?

DDT

an industrial pesticide that has a long-half life in soils and is transported by runoff and rivers where it bioaccumulates, becoming more concentrated as more animals were exposed by consuming each other, linked to declines in wildlife and is representative of human toxicity in the environment

O3 protects life from harmful UV rays

What part of the atmosphere protects life from harmful UV rays?

O3 destroyed by halogens which are common in refrigerants used by humans

What caused the Ozone hole?

The Ozone Hole is above Antarctica despite refrigerants not being used. The atmosphere current moved the refrigerant to Antarctica, supporting the issue of a global perspective

What does the ozone hole above Antarctica signify about the movement of the atmosphere currents?

An Urban World

Urbanization is both positive and negative for the environment

Positive and Negatives of Urbanization

Positive: Reduced transportation distances and cost, less land per person

Negative: Reshapes landscape

We need SUSTAINABLE cities as the middle ground

What is the common ground for urbanization?

People and Nature

Human vs Nature is a false concept, a construct of our society; humans are part of nature

Humans driving species to extinction and agriculture is still natural; the issue is the rate at which they happen

How are humans still a part of the “natural world“?

There is no single natural state of the ecosystem because change is natural; Human influence is a gradient, from heavy to less, but there is no such thing as “no human influence” and evolution is always proceeding with or without humans

Why is the concept of the “natural world“ subjective?

Values, Science

Decision-making relies on

• Human equality

• Economic progress

• Future generations

• Protection of ecosystems and species

What values does decision-making rely on?

• Determine likely outcomes of different scenarios

• Assess uncertainty of outcomes

What science is part of decision-making?

• Always challenged by scientists

• Theories can be disproven, but never proven

• Rely on the scientific method

Why is scientific knowledge NOT absolute?

The Precautionary Principle

States when there is a threat of serious, irreversible environmental damage we should not wait for proof before taking precautionary actions

Prove it Before We Take Action vs Let’s be Cautious and Take Action

Burden of Proof vs The Precautionary Principle

1. The Utilitarian Justification

2. The Ecological Justification

3. The Aesthetic and Recreational Justifications

4. The Moral Justification

5. The Cultural Justifications

5 Justifications for Valuing the Environment

The Utilitarian Justification

The environment has quantifiable value to humans or provides necessary services (viewing what nature has to offer as equivalent to its worldly value); justification by economics

The Ecological Justification

Ecosystems are interconnected and healthy ecosystems may be required for the perseverance of many different species

The Aesthetic and Recreational Justifications

Based around the beauty of nature and joy derived from being in wilderness; spiritual, creative, emotional value of nature

The Moral Justification

Do non-humans have rights? Certain species? Ecosystems? Future generations?

The Cultural Justifications

Thousands of cultures with diverse beliefs related to the environment, nature, and treatment of animals