ESS Notes PDF

Unit 1 Foundations of environmental systems and societies VOCABULARY: Environmental Value System (EVS) = a worldview or paradigm that shapes how an individual, or a group of individuals, perceives and evaluates environmental issues. Cultural, religious, economic, and socio-...

Unit 1 Foundations of environmental systems and societies VOCABULARY: Environmental Value System (EVS) = a worldview or paradigm that shapes how an individual, or a group of individuals, perceives and evaluates environmental issues. Cultural, religious, economic, and socio-political contexts often influence an EVS. System = a collection of connected pieces that form a sophisticated whole. Transfers = occur when energy or matter flows and changes location, but does not change its state. Transformations = occur when energy or matter flows and changes its state. First law thermodynamics = the principle of conservation of energy which states that energy in an isolated system can be transformed, but cannot be created or destroyed. The second law of thermodynamics = as energy is transferred or transformed, more and more of it is wasted. Entropy = the measure of the amount of disorder in a system. Efficiency = the useful energy, the work or output produced by the process divided by the amount of energy consumed. Negative feedback loops = are stabilizing and occur when the output of a process inhibits or reverses the operation of the same processes to produce energy and counteract deviation. Steady-state equilibrium = a feature of open systems in which matter and energy are continuously inputted and outputted, yet the system as a whole stays in a constant state. Feedback loop = the way that changes in one area of an ecosystem impact another, and how those changes influence the source of the changes that caused them, either more or less. Positive feedback loops = tend to increase changes and drive the system towards a tipping point where the new equilibrium is adopted. Sustainability = the use and management of resources that allow full natural replacements of the resources exploited and full recovery of the ecosystems affected by the extraction and use. Sustainable development = development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Natural capital = a term used for natural resources that can produce sustainable natural income of goods and services.  Ecological footprint (EF) = the area of land and water required to sustainably provide all resources at the rate at which they are being consumed by a given population. Pollution = Pollution is the term used to describe the addition of a substance to an environment by human activity at a pace higher than the rate at which the environment can naturally make it harmless. SUMMARY OF THE UNIT Who is involved in the environmental movement: Influencers/influential individuals Independent pressure groups Corporate business Governments Intergovernmental bodies DDT —> dichloro-diphenyl-trichloroethane Types of EVS Ecocentric = considers nature and ecology to be fundamental to humans - Deep ecologist - Soft ecologists - Anthropocentric = belief that people should effectively run the world economy - Technocentric = belief that improvements in technology may address environmental issues. - Supervisors of the environment - Cornucopians (deny the idea that resources on earth are limited.) Systems 1. Inputs, Outputs, and Flows: After receiving inputs from their surroundings, systems internally process them to create outputs. The flow of matter, energy, or information both within and between systems is referred to as a flow. 2. Feedback Mechanisms: Feedback loops affect the dynamics and behavior of systems and can be either positive (amplifying) or negative (stabilizing). Negative feedback loops typically preserve stability or equilibrium, while positive feedback loops can cause rapid growth or collapse. 3. Resilience and Stability: Systems can tolerate disturbances and bounce back, as well as an ability to stay in a stable state over an extended period. Sustainable management of environmental systems requires an understanding of the factors that affect resilience and stability. 4. Boundaries and Interactions: The boundaries of a system define how big it is and how it interacts with other systems. To assess complicated environmental problems and create practical solutions, it is essential to understand these boundaries and interactions. - They can be open, closed, isolated, or living. - Open system: interacts with its environment by exchanging matter and energy. - Closed system: exchanges only energy with its environment. - Isolated system: doesn't exchange any energy or matter with its surroundings. Models of systems A model can be either physical, software-based, mathematical or a diagram; it is a simplified version of the real thing. Strengths: simplicity of usage, used to predict, can be applied to similar situations. Weaknesses: loss of precision, assumptions can be wrong which makes the conclusions wrong, and potentially inaccurate predictions. Energy = work + heat Equilibriums in the system Steady-State Equilibrium: Although there is constant change in the system, the general trend or average remains constant over time. On average, inputs and outputs are balanced. Static equilibrium: There is no net movement or change in the system's elements over time. When inputs and outputs are precisely balanced, the system enters a steady state where it stays steady and unchanged. Stable Equilibrium: after a disturbance, the system goes back to its initial state. It symbolizes an adaptive circumstance in which the system can withstand disturbances and revert to its initial equilibrium position. Unstable Equilibrium: A disturbance pushes the system away from its starting state and prevents it from going back there. The system either experiences a major transition or advances in the direction of a new equilibrium state.  Feedback loops Positive: As a system is altered to a new state, it becomes more unstable. Negative: stabilize as they reduce change and return to their initial state. The ability of a system to recover to its initial state after a disturbance is known as resilience, and it indicates how well-equipped it is to handle larger disturbances. When an ecosystem transitions to a new state where its biodiversity and the services it offers are significantly changed this is known as a tipping point. While natural income includes long-term benefits and services obtained from ecosystems through time, natural result refers to actual things extracted from ecosystems. An environmental impact assessment, or EIA, is a study that is created before a development project that changes the use of land. Therefore, it is essential to determine how the development plan would affect the biotic community and abiotic environment. It will make an effort to measure societal, economic, and environmental changes. Pollution - Primary pollutants: are active in emission - Secondary pollutants: result from the physical or chemical transformation of the primary pollutants - Nonpoint source pollution: is the release of pollutants from numerous and dispersed origins due to which it is difficult to detect where it’s coming from. - Point source pollution: the release of pollutants from a single identifiable site so it is easier to see what is polluting. - Persistent organic pollutants: Are resistant to breaking down and remain active in the environment for a long time. - Biodegradable pollutants: do not persist in the environment and break down quickly. - Acute pollution: large amounts of pollutants are released, causing a lot of harm. - Chronic pollution: results from the long-term release of a pollutant, but in small amounts.  Unit 2 Ecosystems and ecology VOCABULARY: Species: A group of organisms with common characteristics that can interbreed and produce fertile offspring. Population: A group of organisms of the same species living in the same area simultaneously, capable of interbreeding. Habitat: The environment in which a species normally lives. Abiotic Factors: Nonliving physical factors such as temperature influence organisms and the ecosystem. Biotic Factors: The living components of an ecosystem that affect other organisms. Niche: The specific set of biotic and abiotic conditions and resources to which an organism or population responds. Fundamental Niche: The full range of conditions and resources in which a species could survive and reproduce. Realized Niche: The actual conditions and resources in which a species exists due to biotic interactions. Limiting Factors: Factors that slow down the growth of a population. Carrying Capacity: The maximum number of species that can be sustainably supported by a given area. Population Dynamics: The study of factors that cause changes in population sizes. Community: A group of populations living and interacting with each other in a common habitat. Ecosystem: A community and the physical environment it interacts with. Respiration: The conversion of organic matter into carbon dioxide and water in all living organisms, releasing energy. Photosynthesis: The process by which green plants make their own food from water and carbon dioxide, using energy from sunlight. Trophic Level: The position an organism occupies in the food chain, or a group of organisms in a community that occupy the same position in food chains. Ecological Pyramids: Quantitative models usually measured for a given area and time. Productivity: The conversion of energy into biomass over a given period (m^-2 yr^-1).  GP/Gross Productivity: The total gain in energy or biomass per unit area per unit time, the biomass that could be gained by an organism before any deductions. NP/Net Productivity: The gain in energy or biomass per unit area per unit time that remains after deductions due to respiration. GPP/Gross Primary Productivity: The total gain in energy or biomass per unit area per unit time by green plants. NPP/Net Primary Productivity: The total gain in energy or biomass per unit area per unit time by green plants after allowing for losses to respiration (NPP = GPP - R). GSP/Gross Secondary Productivity: The total energy and biomass accumulated by consumers. NSP/Net Secondary Productivity: The total gain in energy or biomass per unit area per unit time by consumers after allowing for losses to respiration. MSY/Maximum Sustainable Yield: The largest crop or catch that can be taken from the stock of a species without depleting the stock. Biome: A collection of ecosystems sharing similar climatic conditions. Biosphere: The part of the Earth inhabited by organisms. Zonation: The change in community along an environmental gradient due to factors such as changes in altitude, latitude, etc. Succession: The process of change over time in an ecosystem involving pioneer, intermediate, and climax communities. Quadrat: A frame of specific size which may be divided into subsections for sampling purposes. Transect: A sample path along which you record the occurrence and distribution of plants and animals in a particular study area. Salinity: The concentration of salt expressed in parts per thousand. Turbidity: The cloudiness of a body of freshwater. Factors that affect population size: Natality Mortality Migration Interactions between populations: Predation: when one animal feeds on another, it lowers carrying capacity. Competition: intraspecific (within the same species) and interspecific (between different species) compete for the same resource.  Herbivory: the consumption of green plants by animals. Parasitism: the relationship of two species in which one feeds on the other without killing its host in order to survive. Mutualism: a type of symbiosis in which there is mutual gain and no suffering between two or more species. Population changes are represented in S and J population curves that describe a generalized response of populations to particular conditions. Respiration: Releases energy Universal process Produces carbon dioxide Photosynthesis: Converts light energy Releases oxygen Drives carbon fixation Food Chain: Linear sequence: Transfer of energy and nutrients from one organism to another in a straight, linear sequence. Trophic levels: Producers Primary consumers Secondary consumers Tertiary consumers Decomposers Energy flow: Energy decreases as it moves up the food chain due to inefficiencies in energy transfer and metabolic processes. Trophic Levels: Hierarchical structure: Position of organisms in a food chain or food web based on their feeding relationships and energy transfer. Producers: First trophic level, e.g., plants. Consumers: Higher trophic levels, including: Primary consumers (herbivores) Secondary consumers (carnivores) Tertiary consumers (top carnivores) Omnivores Decomposers: Final trophic level, consisting of organisms that break down organic matter. Pyramid of Energy: Represents the flow of energy through trophic levels in an ecosystem. Typically pyramid-shaped, with energy decreasing at higher trophic levels due to energy loss through metabolic processes. Provides a visual representation of the inefficiencies in energy transfer between trophic levels. Pyramid of Biomass: Illustrates the total biomass (organic matter) present at each trophic level in an ecosystem. Pyramid of Numbers: Depicts the number of individual organisms at each trophic level in an ecosystem. Can be upright, inverted, or irregularly shaped depending on the population sizes of organisms at each trophic level. The Carbon Cycle: A natural process describing the movement of carbon through the Earth's atmosphere, oceans, soil, and living organisms. Key processes include: 1. Carbon Fixation: Atmospheric carbon dioxide (CO2) is absorbed by plants during photosynthesis, where it is converted into organic carbon compounds, primarily glucose. 2. Respiration: Organisms release carbon dioxide back into the atmosphere through cellular respiration, where organic carbon compounds are broken down to release energy for cellular activities.  3. Decomposition: Dead organic matter, such as plant material and animal remains, is broken down by decomposers (bacteria and fungi), releasing carbon dioxide into the soil and atmosphere. 4. Combustion: Human activities, such as burning fossil fuels (coal, oil, and natural gas) and deforestation, release large amounts of carbon dioxide into the atmosphere, contributing to global warming and climate change. 5. Diffusion and Dissolution: Carbon dioxide dissolves in ocean water, where it can be used by marine organisms for photosynthesis or released back into the atmosphere through diffusion. The Nitrogen Cycle: A vital biogeochemical process describing the movement of nitrogen through various forms in the environment. Key processes include: 1. Nitrogen Fixation: Certain bacteria, such as Rhizobium and cyanobacteria, convert atmospheric nitrogen (N2) into ammonia (NH3) or nitrate (NO3-) ions through biological nitrogen fixation or lightning strikes through atmospheric nitrogen fixation. 2. Nitrification: Ammonia (NH3) produced through nitrogen fixation is converted into nitrite (NO2-) and then into nitrate (NO3-) ions by nitrifying bacteria in the soil. 3. Assimilation: Plants and other organisms take up nitrate (NO3-) and ammonia (NH3) from the soil and incorporate nitrogen into organic compounds, such as proteins and nucleic acids. 4. Ammonification: Decomposers, such as bacteria and fungi, break down organic nitrogen compounds in dead organisms and waste materials, releasing ammonia (NH3) back into the soil. 5. Denitrification: Denitrifying bacteria in anaerobic conditions convert nitrate (NO3-) and nitrite (NO2-) ions into nitrogen gas (N2), which returns to the atmosphere, completing the nitrogen cycle. Human Activity in the Ecosystem: Anthropogenic Biomes: Aquatic: Diverse ecosystems High biodiversity  Important ecosystem services Desert: Extreme conditions Adaptations for survival Fragile ecosystems Forest: Biodiversity hotspots Carbon sequestration Ecosystem services Grassland: Dominant vegetation Biodiversity Human impacts Tundra: Cold climate Low biodiversity Vulnerability to climate change K-strategists and R-strategists: K-strategists: Few offspring Long lifespan Stable environments Examples: Elephants, whales, humans, and large mammals. R-strategists: Many offspring Short lifespan Unstable environments Examples: Insects, rodents, bacteria, and small mammals.  Unit 3 Biodiversity and Conservation VOCABULARY: Species Diversity: The variety of species within a given ecosystem and their relative abundance. Genetic Diversity: The range of genetic material present in a gene pool or population of a species. Habitat Diversity: The variety of different habitats found within a particular ecosystem or biome. Hotspot: A region with high levels of biodiversity that is under threat from human activities. Speciation: The process by which new species form, typically when two populations of the same species become separated and evolve independently. Conservation Biology: The sustainable use and management of natural resources. Preservation Biology: The protection of natural areas from human interference. Summary of the Unit Advantages of High Biodiversity in a Habitat: Greater resilience and stability due to a wide variety of plants Increased genetic diversity, enhancing disease resistance Disadvantages of High Biodiversity in a Habitat: Can result from habitat fragmentation or degradation Some stable and healthy communities have few plant species, which is an exception Unequal Distribution of Biodiversity: Examples of biodiversity hotspots include: Atlantic Forest, Brazil Caribbean islands California floristic province Himalaya Darwin's Theory of Evolution 1. Variation: Individuals in a population show differences in traits (e.g., size, color) due to genetic variation. 2. Competition: Limited resources lead to competition for survival and reproduction. 3. Natural Selection: Individuals with advantageous traits are more likely to survive and reproduce, passing those traits to their offspring. 4. Adaptation: Favorable traits accumulate over time, leading to adaptations that improve fitness in a particular environment. 5. Speciation: Over generations, accumulated differences can lead to the formation of new species. Plate Tectonics and Biodiversity Creation of New Habitats: Mountains and islands formed by plate tectonics provide new environments for species to inhabit. Isolation of Populations: Isolated populations evolve independently, potentially forming new species. Influence on Climate Patterns: Plate activity affects climate, which in turn impacts habitats and species distribution. Earth's Formation and Biodiversity Age of Earth: Approximately 4.6 billion years. Extinction Rate: 100 species per million species per year. Factors Influencing Biodiversity Factors Maintaining Biodiversity: Complexity of the ecosystem Stage of succession Limiting factors Inertia Factors Leading to Loss of Biodiversity: Natural hazards Habitat fragmentation Pollution and modern agricultural practices Overexploitation Spread of disease Characteristics Making Species Prone to Extinction: Narrow geographical range Small population size or declining numbers Low population densities and large territories Specific population dynamics Large body size Low reproductive potential Seasonal migration patterns Specialized niche requirements Edibility to humans Island habitats IUCN: International Union for the Conservation of Nature Importance of Conserving Biodiversity Values of Biodiversity: Sources of food and natural products Environmental services Scientific and educational value Human health benefits Conservation Efforts Types of Conservation Organizations: Intergovernmental organizations Governmental organizations Non-governmental organizations  Unit 4 Water, Food Production, Systems, and Society VOCABULARY: Water Budget: An estimate of the amount of water in storage and flows in the water cycle. Water Pollution: Contamination of water bodies by pollutants, directly or indirectly. Eutrophication: Excessive growth of plants and phytoplankton in water bodies due to nutrient inputs. Fishery: Harvesting fish in some manner. Aquaculture: Farming of aquatic organisms in coastal and inland areas to enhance production. Biochemical Oxygen Demand (BOD): Amount of dissolved oxygen needed to break down organic material in water by microorganisms. Indicator Species: Species that indicate the health of an environment by their presence, absence, abundance, or scarcity. Biotic Index: Measures pollution by assessing its impact on species within a community based on their tolerance, diversity, and abundance. Summary of the Unit: The Water Hydrological Cycle: 1. Evaporation: Water evaporates from oceans, rivers, lakes, and soil into the atmosphere. 2. Condensation: Water vapor cools and condenses into clouds or dew, releasing heat energy. 3. Precipitation: Water droplets combine to form rain, snow, sleet, or hail, falling back to Earth. 4. Infiltration: Precipitated water enters the ground, replenishing groundwater. 5. Runoff: Excess water flows over the land surface, forming streams and rivers, returning to oceans. Human Impact on the Water Cycle: 1. Withdrawals 2. Discharges 3. Diverting water sources Uses of Freshwater: 1. Domestic purposes 2. Agriculture 3. Industry 4. Hydroelectric power generation 5. Transportation 6. Marking boundaries between states Solutions to Freshwater Issues: Reservoirs Redistribution Desalination Artificially recharging aquifers Continental Shelf: The extension of continents under seas and oceans. Fishery Threats: 75% of fisheries are under threat of over-exploitation. Factors affecting carrying capacity include reproductive strategy, longevity, and habitat resources. Water Pollution Types: 1. Anthropogenic 2. Point source or non-point source 3. Organic or inorganic 4. Direct or indirect Measuring Water Pollution: 1. BOD (Biochemical Oxygen Demand) 2. Indicator Species 3. Biotic Indices Eutrophication Process: 1. Nutrient input from fertilizers 2. Phosphate promotes algae growth 3. Algal bloom blocks light, killing plants below 4. Increased microorganisms decompose algae 5. Oxygen depletion causes ecosystem collapse  Unit 5 Soil Systems and Society VOCABULARY: LEDC: Less Economically Developed Countries. MEDC: More Economically Developed Countries. Agribusiness: Agricultural production business. Commercial Agriculture: Large-scale crop and livestock production for sale. Subsistence Agriculture: Farming for self-sufficiency, enough for a family. Summary of the Unit: Soil Definition: Soil is a complex mixture of minerals, organic matter, water, air, and organisms, forming the Earth's crust's upper layer, and supporting plant growth. Soil Storages: Nutrients Water Carbon Soil Structure: Consists of mineral particles Organized into horizons Porosity and Permeability: Porosity: Volume of pore spaces in soil, influencing water and air retention. Permeability: Rate of water and air movement through soil, influenced by pore spaces and soil texture. Soil pH: Measures acidity or alkalinity on a scale from 0 to 14, with 7 being neutral. Types of Farming Systems: 1. Subsistence 2. Commercial 3. Pastoral Farming’s Energy Budget: Refers to energy use and management in agriculture, including inputs like sunlight, machinery, and fertilizers, and outputs like crops and environmental impacts. Sustainable practices optimize energy use, reduce waste, and promote renewable sources. Terrestrial vs. Aquatic Food Production: Terrestrial: Advantages: 1. Land Use Efficiency 2. Control Over Environmental Conditions Disadvantages: 1. Water Scarcity 2. Soil Degradation Aquatic: Advantages: 1. High Yield Potential 2. Water Conservation Disadvantages: 1. Pollution and Environmental Impact 2. Habitat Destruction Increasing Sustainability for Food Supplies: Maximize yield Reduce food waste Monitor and control Change attitudes towards food Reduce processing, packaging, transport Soil Degradation: Definition: Deterioration of soil quality and fertility due to human activities. Causes: Erosion, compaction, salinization, nutrient depletion, pollution, loss of organic matter. Impacts: Reduces agricultural productivity, impairs water quality, contributes to desertification, and exacerbates climate change. Soil Erosion: Definition: Detachment, transport, and deposition of soil particles by wind, water, or human activities. Types: Water erosion (rill, gully, sheet), wind erosion, erosion by gravity (landslides). Causes: Deforestation, overgrazing, improper land use, intensive agriculture, construction, climate change. Soil Conservation: Addition of soil conditioners Wind Reduction Improved irrigation techniques Crop rotation  Unit 6 Atmospheric Systems and Society Summary of the Unit: Greenhouse Effect: Definition: Natural process where gases in Earth's atmosphere trap heat, warming the planet. Key Gases: Carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), water vapor. Enhanced Greenhouse Effect: Intensified by human activities, leading to global warming and climate change. Ozone Layer and Hole: Ozone Layer: Region of Earth's stratosphere with high ozone concentration, blocking UV radiation. Ozone Hole: Depleted ozone concentration over Antarctica, caused by ozone-depleting substances (ODS) like CFCs and halons. Impacts: Increased UV exposure, health risks, and marine ecosystem damage. ODS (Ozone-Depleting Substances): Definition: Synthetic compounds with chlorine or bromine, destroy ozone in the stratosphere. Examples: CFCs, halons, carbon tetrachloride, methyl chloroform. Regulation: The Montreal Protocol regulates ODS production and use to protect the ozone layer. Montreal Protocol: International Agreement: Treaty aimed at phasing out ODS. Goals: Reduce ODS emissions, protect the ozone layer, and safeguard health and the environment. Success: Significant reductions in ODS, and gradual recovery of the ozone layer. Air Pollution: Definition: Presence of harmful substances in the air from human activities like industrial emissions, vehicle exhaust, and agriculture. Health Impacts: Respiratory diseases, cardiovascular problems, health issues in vulnerable populations. Acid Deposition Pollutants and Sources: Pollutants: Sulfur dioxide (SO2), nitrogen oxides (NOx), particulate matter (PM). Sources: Industrial emissions, vehicle exhaust, fossil fuel combustion, agriculture. Pollution and Deposition Management: Prevention and Control: Emission controls, renewable energy, fuel efficiency, sustainable land management. International Cooperation: Collaboration among governments, industries, and stakeholders for effective mitigation.  Unit 7 Climate Change and Energy Production VOCABULARY: Energy Security: Ability to secure reliable, affordable energy supplies. GWP (Global Warming Potential): Measure of heat a mass of greenhouse gas traps compared to CO2. Mitigation: Reduction or stabilization of greenhouse gas emissions and their removal from the atmosphere. Adaptation: Adjustment in response to climate stimuli or effects. Adaptive Capacity: Ability to respond to climate variability and change. Summary of the Unit: Energy Sources and Choices: Factors Influencing Choices: Supply availability, technological developments, politics, economics, cultural attitudes, sustainability, and environmental considerations. Energy Conservation: Can limit growth in demand, contributing to energy security. Fossil Fuels: Stored solar energy, non-renewable, significant impact on atmospheric CO2 levels. Lifespan Estimates: Coal (230 years), gas (170 years), oil (100 years). Peak Oil: Decline in oil production after reaching peak. Energy Crisis and Alternatives: Hydrogen economy or nuclear fusion post-fossil fuels. Only 14% of energy is renewable. Climate and Weather: Climate: Long-term patterns, regional characteristics, stable and predictable. Weather: Short-term conditions, immediate phenomena, variable and unpredictable. Climate Change: Definition: Long-term shifts in climate patterns.  Causes: Human activities like burning fossil fuels, and deforestation. Impacts: Severe weather, rising sea levels, biodiversity loss, threats to food and water security. Global Climate Models: Definition: Simulations predicting future climate conditions. Purpose: Study climate variability, and project scenarios, and inform policy.  Unit 8 Human Systems and Resource Use VOCABULARY: Crude Birth Rate (CBR): Number of births per 1,000 individuals in a population per year. Crude Death Rate (CDR): Number of deaths per 1,000 individuals in a population per year. Natural Increase Rate (NIR): Rate of human population growth expressed as a percentage per year. Doubling Time (DT): The time in years it takes for a population to double in size. Total Fertility Rate (TFR): Average number of children each woman has over her lifetime. Renewable Natural Capital: Resources that can be regenerated or replaced as fast as they are used. Non-renewable Natural Capital: Resources that are irreplaceable or only replaceable over geological timescales. Carrying Capacity: Maximum number of species that can be sustainably supported by a given area. Summary of the Unit: Demographics Definition: The study of population change dynamics. Global Population Growth: Currently follows an exponential curve. Human Development Index (HDI): Classifies countries into MEDCs (More Economically Developed Countries) and LEDCs (Less Economically Developed Countries) based on well- being. Examples of MEDCs - South Africa - Most European countries Examples of LEDCs - Large areas of Asia - South America Population Dynamics More people require more resources. More people produce more waste. A higher population leads to greater environmental impact. Population stability occurs when birth and death rates are equal. 20% of the global population lives in MEDCs, while 80% lives in LEDCs. Overpopulation - Occurs in countries with high population densities and an inability to support a high standard of living. Reasons for Large Families 1. High infant and childhood mortality rates. 2. Security in old age. 3. Economic asset. 4. Status of women. 5. Lack of contraceptives. Strategies to Reduce Family Size 1. Provide education. 2. Improve health. 3. Make contraceptives available. 4. Enhance income. 5. Improve resource management. Demographic Transition Model (DTM) Definition: Describes the pattern of declining mortality and fertility rates in a country due to social and economic development. Stages: The model is divided into several stages. Natural Capital and Income Natural Capital: Resources with value to humans as goods and services. Natural Income: Rate of replacement of natural capital. Examples of Changing Value of Natural Capital 1. Cork Forests: Once essential, now replaced by plastics, reducing their value and leading to land use changes. 2. Lithium: Little known 30 years ago, now in high demand. Valuing Natural Capital 1. Use Valuation: Economic price. 2. Non-use Valuation: Intrinsic value. Solid Domestic Waste (SDW) Definition: Trash from residential and urban areas, including paper, organic materials, glass, metals, plastic, textiles, paints, old batteries, and electronic waste. Percentage: About 5% of total waste. Current Model: Linear (take, make, dump). Sustainable Model: Circular economy aims to: Restore the environment. Use renewable energy sources. Eliminate or reduce toxic waste. Eradicate waste through careful design. Waste Minimization Strategies (3Rs) 1. Reduce 2. Recycle 3. Reuse Waste Disposal Strategies Incinerators: Burn waste at high temperatures, causing air pollution. Anaerobic Digestion: Biodegradable matter broken down by microorganisms in the absence of oxygen, producing fertilizers. Domestic Organic Waste: Composted. Ecological Footprint (EF)  Definition: A model estimating the demand human populations place on the environment. Unsustainability Indicator: When EF exceeds the available area, indicating the population exceeds the area's carrying capacity. The inverse of Carrying Capacity: EF is essentially the inverse of carrying capacity.