Introduction to Environmental Science: Natural Systems, Sustainability, and Ecosystem Services

Natural Environment:
- Definition: This encompasses all living and non-living things that occur naturally on Earth.
- Components:
  - Biotic Factors: All living elements, including plants, animals, and microorganisms.
  - Abiotic Factors: All non-living elements, including minerals, rocks, magma, water bodies, and layers of the atmosphere.
Built Environment:
- Definition: This refers to the part of the physical environment constructed by humans through the application of science, technology, culture, and other human activities.
- Attributes: Includes places and spaces created or modified by people, such as buildings, parks, and transportation systems.

Etymology of "Environment":
- The term is derived from the French word "Envirormer," which means to encircle or surround.
Formal Definitions of Environment:
1. The circumstances and conditions that surround an organism or a group of organisms.
2. The social and cultural conditions that affect an individual or a community.
Definition of Science:
- A systematically organized body of knowledge on a particular subject.
The Scope of Environmental Science:
- It is an interdisciplinary field that seeks to understand:
  - How the Earth works.
  - How life on Earth is sustained.
  - What leads to environmental problems.
  - How these problems can be solved.

Holistic Approach: Environmental science utilizes a multidisciplinary framework to identify and solve problems comprehensively.
Case Study: Achieving a Clean Energy Future via Electric Vehicles:
- Solving this single goal requires integration across numerous disciplines:
  - Political Science: Determining which policies lead to sustainable solutions.
  - Engineering: Designing better vehicles and improving mechanical efficacy.
  - Urban Planning: Creating urban designs that reduce energy use.
  - Chemistry: Developing better battery technology.
  - Economics: Assessing the benefits and costs of various energy sources.
  - Sociology: Understanding how people adopt new ideas and technologies.
  - Ecology: Evaluating how energy production affects biological populations.
  - History and Psychology: Understanding past trends and human behavior to drive future change.

Sustainability is achieved at the intersection of three primary domains, as adopted from the $2002$ University of Michigan Sustainability Assessment:

Environmental Sphere:
- Focuses on natural resource use, environmental management, and pollution prevention (air, water, land, waste).
Social Sphere:
- Focuses on standard of living, education, community, and equal opportunity.
Economic Sphere:
- Focuses on profit, cost savings, economic growth, and research and development ( $R\&D$ ).
Intersectional Sustainability Domains:
- Social-Environmental: Environmental justice and natural resources stewardship (locally and globally).
- Environmental-Economic: Energy efficiency and subsidies/incentives for the use of natural resources.
- Economic-Social: Business ethics, fair trade, and worker's rights.

Direct Use Value:
- Definition: Tangible benefits or products that can be used directly from nature.
- Examples: Wood, fodder, and fuel.
Indirect Use Value:
- Definition: Intangible benefits or services provided by nature.
- Example: Flood control.

Ecosystem services are the benefits humans obtain from ecosystems, categorized into three functional groups:

Provisioning Services (Goods provided by ecosystems):
- Food: Crops, livestock, capture fisheries, aquaculture, and wild foods.
- Fiber: Timber, cotton, hemp, silk, and wood fuel.
- Energy: Biological sources for power.
- Genetic Resources: Biological diversity for breeding and medicine.
Regulating Services (Regulation of ecosystem processes):
- Climate Regulation: Includes global levels, such as $CO_2$ sequestration, as well as regional and local climate control.
- Water and Soil: Erosion regulation, nutrient regulation, and water purification.
- Biological Regulation: Disease regulation, pest regulation, and pollination.
- Safety: Natural hazard regulation and air quality regulation.
Cultural Services (Non-material benefits):
- Values: Spiritual and religious values, aesthetic values, and educational values.
- Personal and Social: Knowledge systems, inspiration, social relations, and a "sense of place."
- Activity: Recreation and ecotourism.

World Environment Day: Observed annually on June 5.
Summary of Critical Issues:
- Pollution (Air, water, and soil).
- Waste disposal and management.
- Climate change and global warming.
- Sea-level rise.
- Acid rain and ocean acidification.
- Biodiversity loss and deforestation.
- Over-population.

Current Status: The global population has doubled in the last $40 \text{ years}$ and currently exceeds $8 \text{ billion}$ .
Projections: At the current rate of growth, the population may reach $9 \text{ billion}$ by $2040$ .
Historical Context:
- It took the entirety of human history until the early $1800\text{s}$ to reach the first $1 \text{ billion}$ people.
- The population reached $3 \text{ billion}$ in $1960$ .
- Current Rate of Increase: The world currently gains $1 \text{ billion}$ people approximately every $11 \text{ years}$ .