ch01

Introducing Environmental Science and Sustainability

  • Importance of understanding environmental science in relation to sustainability.

Overview of Chapter 1

  • Key topics:

    • Human Impacts on The Environment

    • Population, Resources and the Environment

    • Sustainability

    • Environmental Science

    • Addressing Environmental Problems

Food as a Lens for Our Relationship to the Environment

  • A food item like a chicken sandwich requires various inputs:

    • Wheat, chicken, other ingredients

    • Pesticides and fertilizers for agriculture

    • Energy (petroleum) for production, transport, and waste treatment

    • Packaging and landfill contributions

  • Individual food choices have significant environmental impacts.

  • Need for adapting food-production practices for sustainability.

The Environment (Earth)

  • Life has persisted on Earth for approximately 3.8 billion years.

  • Earth’s suitability for life:

    • Water covers over 75% of the planet.

    • Habitable temperature ranges with moderate sunlight.

    • Atmosphere provides necessary oxygen and carbon dioxide.

    • Fertile soil contains essential minerals for plant growth.

  • Modern humans have been around for only about 100,000 years.

Increasing Human Numbers

  • Population changes from 1950 to 2016:

    • In 1950, eight cities had populations over 5 million; NYC at 12.3 million.

    • In 2016, major urban areas had 10 largest areas totaling around 200 million.

    • Tokyo has a population of 17.8 million, greater metropolitan area 38.1 million.

Human Population Growth

  • Estimated global population could reach 9.3 - 10.5 billion by the end of the 21st century.

  • By 2017, the population was approximately 7.5 billion, having surpassed 7 billion in 2011.

  • Fast-growing population areas may experience worsening quality of life.

  • Population growth is exponential.

Population and Extreme Poverty

  • Over 50% of the global population lives in extreme poverty with basic needs unmet (food, shelter, healthcare).

  • Fertility rates globally are around 3 children per family, expected to decline by century's end.

  • Meeting population demands without exploiting resources poses significant challenges.

Countries Differentiated Based on Wealth

  • Highly Developed Countries (HDC)

    • Features: Complex industrial bases, low population growth, high per capita incomes.

    • Examples: U.S., Canada, Japan.

  • Less Developed Countries (LDC)

    • Features: Low development, high fertility rates, high infant mortality, low per capita income.

    • Examples: Bangladesh, Kenya, Nicaragua.

Income Disparity Between Rich and Poor

  • Increasing income disparity in many nations.

    • Significant gaps exist between wealthy and poor citizens with unequal access to resources.

    • Growing disparities noted between urban and rural populations, especially in LDCs.

  • Total national wealth does not always accurately reflect citizens' well-being.

Population, Resources, and Environment: Needs for Survival

  • Generalizations about survival resources:

    • Essential resources for survival are limited.

    • Rapidly increasing populations can lead to local resource depletion.

Individual Resource Consumption

  • Individual resource consumption can vastly exceed survival needs.

    • Wealthier nations consume disproportionately, risking global resource exhaustion.

Types of Natural Resources

  • Natural Resources:

    • Renewable Natural Resources:

      • Direct solar energy, wind, tides, clean air, fresh water, biological diversity.

    • Nonrenewable Natural Resources:

      • Minerals (gold, salt), fossil fuels (coal, oil, natural gas).

Resource Consumption

  • Human use of materials and energy is both an economic and social undertaking.

  • Populations in HDCs are the largest consumers.

  • Unsustainable resource consumption arises when demand depletes resources, undermining future quality of life.

Ecological Footprint

  • Represents land and water necessary for an individual's consumption.

    • Earth's productive area is 11.4 billion hectares; each person is allotted approximately 1.5 hectares.

    • Current global average footprint is approximately 2.7 hectares, indicating overshoot.

Ecological Overshoot

  • Humanity has surpassed Earth's biocapacity, requiring 2 Earths worth of resources for current consumption levels.

Ecological Footprint Comparison

  • There is significant variation in ecological footprints among different countries and regions.

IPAT Model

  • Represents environmental impacts as a product of:

    1. I (Environmental Impact)

    2. P (Population)

    3. A (Affluence per person)

    4. T (Environmental effects of technologies)

Average Fuel Efficiency in U.S.

  • Vehicle fuel efficiency trends from 1988 to 2015, showing increases and shifts like hybrid popularity.

    • Average fuel economy of passenger cars has improved by ~50% since 1980.

Sustainability Requirements

  • Necessitates a long-term perspective to meet present needs without compromising future support.

Challenges in Achieving Sustainability

  • Current behaviors lead to:

    • Rapid resource consumption and pollution.

    • Population growth despite finite resources.

    • Non-sustainable practices leading to resource extraction.

Tragedy of the Commons

  • Concept introduced by Garrett Hardin illustrating the tension between short-term benefits and long-term sustainability.

  • Emphasizes common-pool resource challenges.

  • Collaborative stewardship enhances sustainability efforts.

Sustainable Development - Systems Concept

  • Defined as economic development that fulfills present needs without hindering future generations' needs.

  • International summits are addressing these issues collaboratively.

Environmental Science

  • An interdisciplinary field examining humanity's relationship with both living and non-living elements of nature.

    • Draws on biology, ecology, geography, chemistry, geology, physics, economics, sociology, demography, and politics.

Earth’s System and Environmental Science

  • Definition of a system as interacting components functioning as a whole.

  • Global Earth systems include climate, atmosphere, land, oceans, etc.

  • Ecosystems are natural systems comprising communities of organisms and their environments.

  • These systems are in dynamic equilibrium, involving feedback processes.

Feedback Mechanisms

  • Negative Feedback:

    • A change that triggers a counteracting response.

  • Positive Feedback:

    • A change that triggers an intensifying response, e.g., ice melt leading to accelerated warming.

The Nature of Science

  • Science operates as a dynamic process to understand the natural world through observation and experimentation.

  • Peer review serves to validate or reject findings, allowing for error correction in scientific research.

The Scientific Method

  • A systematic approach for problem-solving involving hypothesis formulation and experimentation to test those hypotheses.

Experimental Design and Variables

  • Variable: A factor that can influence a process, altered to assess its effects.

  • Experimental Group: The group where the chosen variable is altered.

  • Control Group: A baseline group where no variables are altered for comparison.

Scientific Knowledge and Theory

  • A theory integrates multiple hypotheses supported by extensive evidence and peer review.

  • Acknowledges scientific knowledge evolves with new findings and that absolute truths are unattainable.

Climate Change: Hypotheses and Theory

  • Investigates the impact of gases like CO2 from fossil fuels on climate, emphasizing the need for extensive data collection to adapt hypotheses.

Addressing Environmental Problems

  • Ideal approach involves:

    1. Scientific assessment

    2. Risk analysis

    3. Public engagement

    4. Political action

    5. Long-term evaluation

  • Recognizes complexity in reality and necessitates public pressure for solutions.

Environmental Science in Practice: Lake Washington

  • A case study demonstrating poor urban sprawl and its impact on Lake Washington's health due to nutrient-rich sewage inputs.

  • The study conducted by University of Washington identified the key pollutants and their effects on local ecosystems.

Recovery Plan for Lake Washington

  • Despite political challenges, an extensive pollution control project was implemented, which successfully restored the lake's health by managing waste outputs.

Data on Recovery of Lake Washington

  • Presented graphs show the improvement in lake conditions, indicating reduction in phosphorus and chlorophyll levels post-remediation efforts.