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17 limits to growth of human populations
The document discusses several topics related to limits on human population growth and ecological footprints, including: 1) Calculating ecological footprints can quantify the environmental demands of human populations. Developed countries typically have much larger footprints than developing countries. 2) Technology, affluence, and population size all contribute to a population's environmental impact. Reducing waste, reusing materials, recycling, and improving efficiency can help reduce footprints. 3) Policies around development, education, family planning and economic growth can influence population dynamics and waste generation. Environmental impact assessments also aim to evaluate development projects' effects on the environment.
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17 limits to growth of human populations
- 1. Limits to HumanPopulationLimits to Human Population Growth and EcologicalGrowth and Ecological FootprintsFootprints IB syllabus: 3.7.1-3.7.2IB syllabus: 3.7.1-3.7.2 3.8.1-3.8.53.8.1-3.8.5 Calculate your ecological footprintCalculate your ecological footprint Video – The Human FootprintVideo – The Human Footprint
- 2. Syllabus StatementsSyllabus Statements •2.7.3: Describe and evaluate the use of environmental impact assessments
- 3. Syllabus StatementsSyllabus Statements •3.7.1: Explain the difficulties in applying the concept of carrying capacity to local human populations • 3.7.2: Explain how reuse, recycling, remanufacturing and absolute reductions and material use can affect human carrying capacity
- 4. Syllabus StatementsSyllabus Statements •3.8.1: Explain the concept of an ecological footprint as a model for assessing the demands that human populations make on their environment • 3.8.2: Calculate from appropriate data the ecol,ogical footprint of a given population, stating the approximations and assumptions involved • 3.8.3: Describe and explain the differences between the ecological footprints of two human populations, one from an LEDC one from an MEDC • 3.8.4: Discuss how national and international development policies and cultural influences can affect human population dynamics and growth • 3.8.5: Describe and explain the relationship between population, resource consumption and technological development, and their influence on carrying capacity and material economic growth.
- 5. vocabularyvocabulary • Ecological footprint •Environmental Impact Assessment
- 6. Carrying CapacityCarrying Capacity •Environmental resistance = all factors which limit the growth of populations • Population size depends on interaction between biotic potential and environmental resistance • Carrying capacity (K) = # of individuals of a given population which can be sustained infinitely in a given area • Should be able to estimate this by examining the requirements of a species and the
- 7. Forms of GrowthFormsof Growth • Exponential growth starts slow and proceeds with increasing speed – J curve results – Occurs with few or no resource limitations • Logistic growth (1) exponential growth, (2) slower growth (3) then plateau at carrying capacity – S curve results – Population will fluctuate around carrying capacity
- 8. © 2004 Brooks/Cole– Thomson Learning Time (t) Time (t) Populationsize(N) Populationsize(N) K Exponential Growth Logistic Growth Population Growth CurvesPopulation Growth Curves
- 9. Carrying capacity isDifficult forCarrying capacity is Difficult for HumansHumans 1. Use a wide range of resources 2. If a resource becomes limiting humans readily substitute others 3. Requirements vary according to lifestyle • Differ in time, by populations, by areas 1. Technology impacts resources used and available 2. Import and export moves resources beyond local boundaries -Import and export change K for an area but have no impact on its global level
- 10. • Human carryingcapacity determined by – Rate of energy and material consumption – Extent of human interference in global life support systems – environmental degradation – Levels of pollution created • Recycling, Reuse and Remanufacturing – Reduce these impacts – BUT can increase carrying capacity as well
- 11. WasteWaste • U.S. 4.6% world population & 33% of the worlds solid waste production • Only 1.5% is municipal solid waste, MSW from homes & businesses (garbage) • 200 million metric tons MSW produced per year • Average 1700 lbs per person yearly • Timeline of US waste stream • http://www.tufts.edu/tuftsrecycles/usstats.html
- 12. Municipal 1.5% Sewage sludge 1% Mining andoil and gas production 75% Industry 9.5% Agriculture 13% Sources of Solid Waste in the US
- 13. We throw away…Wethrow away… • Enough aluminum to rebuild the country’s entire commercial airline fleet in 3 months • 18 billion disposable diapers yearly • 30 million cell phones per year • 2.5 million nonreturnable plastic bottles per hour • 1.5 billion pounds of edible food per year • EPA names electronic wastes as the fastest growing environmental concern
- 14. Ever think aboutKleenex?Ever think about Kleenex? • http://www.kleercut.net/en/ • http://www.greenpeace.org/usa/assets/bin aries/tissue-guide-view-at-a-glance
- 15. What are ouroptionsWhat are our options • 2 methods of dealing with our solid & hazardous wastes 1. Waste management = a high waste approach – waste production is unavoidable product of growth 2. Waste & pollution prevention = a low waste approach recognizing that recycling or reducing use of materials
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- 17. High-quality energy Matter Pollution prevention by reducing matter throughput Sustainable low-waste economy Recycle and reuse Pollution control by cleaning up some pollutants Matter output Low-quality energy (heat) Waste matter and pollution Matter Feedback Energy Feedback Inputs (fromenvironment) System Throughputs Outputs (from environment)
- 18. We do haveoptions.We do have options.
- 19. 1st Priority 2ndPriority Last Priority Primary Pollution and Waste Prevention • Change industrial process to eliminate use of harmful chemicals • Purchase different products • Use less of a harmful product • Reduce packaging and materials in products • Make products that last longer and are recyclable, reusable or easy to repair Secondary Pollution and Waste Prevention • Reduce products • Repair products • Recycle • Compost • Buy reusable and recyclable products Waste Management • Treat waste to reduce toxicity • Incinerate waste • Bury waste in landfill • Release waste into environment for dispersal or dilution
- 20. Landfill Produce Less Waste Convertto Less Hazardous or Nonhazardous Substances Put in Perpetual Storage Manipulate processes to eliminate or reduce production Recycle and reuse Land treatment Incineration Thermal treatment Chemical physical, and biological treatment Ocean and atmospheric assimilation Underground injection Waste piles Surface impoundments Salt formations Arid region unsaturated zone
- 21. The Ecoindustrial revolutionTheEcoindustrial revolution • Combine interests to achieve economic, environmental & industrial sustainability • Clean production or industrial ecology • Create closed systems of material flow • My waste your raw material • Many benefits incl. reduced waste material, less pollution, stimulate production of cleaner products
- 22. Pharmaceutical plant Local farmers Fish farming Cement manufacturer Areahomes Wallboard factory Greenhouses Oil refinery Sulfuric acid producer Electric power plant Sludge Sludge Waste Heat W aste Heat Waste Heat W aste Heat Waste Heat Surplus Natural gas Surplus Sulfur Surplus Naturalgas Waste Calciumsulfate
- 23. Strategies: 1. ReuseStrategies:1. Reuse • Good form of waste reduction • Conserves energy & raw materials • But we live in a disposable society – paper towels, paper plates, plastic utensils … • Examples – Refillable glass or PET plastic bottles – Tool libraries – Cloth shopping bags
- 24. Aluminum can, usedonce Steel can used once Recycled steel can Glass drink bottle used once Recycled aluminum can Recycled glass drink bottle Refillable drink bottle, used 10 times 0 8 16 24 32 Energy Consumption (thousands of kilocalories)
- 25. Strategies: 2. RecyclingStrategies:2. Recycling 1. Primary (closed loop) recycling • Post consumer wastes are recycled to produce new products • Reduce pollution, energy use, resource use 1. Secondary (downcycling) • Waste materials converted into different & usually lower quality products 1. If items are recyclable that doesn’t mean it necessarily is being recycled
- 26. Reduces global warming Reduces acid deposition Reducesurban air pollution Make fuel supplies last longer Reduces air pollution Saves energy Reduces energy demand Reduces water pollution Recycling Reduces solid waste disposal Reduces mineral demand Protects species Reduces habitat destruction Benefits of Recycling
- 27. Recycling IIRecycling II •60 – 80% of MSW could be recycled & composted • Large scale recycling requires centralized materials recovery facilities • Financial aspect often hampers recycling programs • We still lack (1) goverment support for recycling, (2) demand for recycled products, (3) proper pricing to goods to account for environmental impact
- 28. Outside users Pipeline Shredder Energy recovery (steam and electricity) Incinerator (paper,plastics, rubber, food, yard waste) Food, grass, leaves Separator Metals Rubber Glass Plastics Paper Residue Compost Recycled to primary manufacturers Landfill and reclaiming disturbed land Fertilizer Consumer (user)
- 29. Removing toxic materialsRemovingtoxic materials 1. Bioremediation use microorganisms to remove toxins 2. Phytoremediation plants soak up pollutants in the soil 3. Chemical methods of detoxification cyclodextrin attracts & binds chemicals 4. Plasma torch extreme high temperatures decompose hazardous materials
- 30. How can wequantify the impactHow can we quantify the impact we have?we have? • Calculate an Ecological Footprint • Model for quantifying the demands that human populations make on their environment • The area of land in the same vicinity as the population that would be required to provide for all of the population’s resources and assimilate all of it’s wastes • It is the inverse of the carrying capacity
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- 32. Different Populations, DifferentDifferentPopulations, Different ProblemsProblems • Human pressure on the environment caused by three factors • I = P x A x T – Population size – Affluence – Technology
- 33. Ecological Footprints byWorld RegionEcological Footprints by World Region • The average American places at least 20 times the demand on Earth’s resources as does an average person in Bangladesh Fig. 5.7 here
- 34. Affluence in theUnitedAffluence in the United StatesStates • Consume the largest share of 11 of 20 major commodities • Eat more than three times the global average in meat • Lead the world in paper consumption • Environment improves with increasing affluence • Enables wealthy to clean up immediate environment by transferring waste to more distant locations. • Affluent isolate themselves and unaware of the environmental stresses caused by their consumptive lifestyles.
- 35. Calculate a Footprintfor a given groupCalculate a Footprint for a given group • Calculations are approximations • Total area required is the sum of these two per capita requirements multiplied by total population
- 36. Footprint Calculation IgnoresFootprintCalculation Ignores • land and water needed – for aquatic and atmospheric resources – for the assimilation of waste other than CO2 – For production of energy or materials needed to support arable land in an area – To replace productive land lost by urbanization and so on
- 37. Calculate your FootprintCalculateyour Footprint • http://www.myfootprint.org/ • Did you know that the planet takes 1 year and 4 months to regenerate the material that we consume in 1 year • We are in an overshoot liquidating the earth’s assets
- 38. Country ComparisonCountry Comparison •LEDC – less economically developed country: a country with low to moderate industrialization and low to moderate average GNP per capita • MEDC – more economically developed country: a highly industrialized country with high average GNP per capita
- 39. Key Nations forthe futureKey Nations for the future • China footprint has quadrupled in the last four decades – second only to US • African Nations individuals consume little but population growth is causing them to approach their capacity • Canada if everyone consumed like them, we would need 4.3 earths • Canada is 7.4 global hectares per person but the US is 9.2!
- 40. Figure 1 tracks,in absolute terms, the average per person resource demand (Ecological Footprint) and per person resource supply (Biocapacity) in United States of America since 1961. Biocapacity varies each year with ecosystem management, agricultural practices (such as fertilizer use and irrigation), ecosystem degradation, and weather.
- 41. Figure 2 showsthe components of the average per person Ecological Footprint in United States of America since 1961.
- 42. Table 1 outlinessome basic data about United States of America in 2005. Ecological Footprint and Biocapacity are calculated by Global Footprint Network. The Human Development Index is calculated by the United Nations Development Programme.
- 43. Figure 1 tracks,in absolute terms, the average per person resource demand (Ecological Footprint) and per person resource supply (Biocapacity) in Congo DR since 1961. Biocapacity varies each year with ecosystem management, agricultural practices (such as fertilizer use and irrigation), ecosystem degradation, and weather.
- 44. Figure 2 showsthe components of the average per person Ecological Footprint in Congo DR since 1961.
- 45. Table 1 outlinessome basic data about Congo DR in 2005. Ecological Footprint and Biocapacity are calculated by Global Footprint Network. The Human Development Index is calculated by the United Nations Development Programme.
- 46. Effects of Policyon PopulationsEffects of Policy on Populations • Domestic & International Policy Effects • Policies target death rates Stimulate rapid growth – Agricultural development – Improving public health and sanitation – Improved service infrastructure • These policies lower mortality without significant effects on fertility • http://www.globalgiving.com/dy/v2/content/themes.html? themeName=Economic+Development • Examples = Oxfam, UNICEF
- 47. Effects of Policyon PopulationsEffects of Policy on Populations • Policies targeting birth rates – Economic growth itself may lead to decreasing birth rates (Demographic Transition Hypothesis) – Education about birth control – Family planning service development – Increasing women’s education more economic & personal freedoms – Removing parental dependence on children in old age
- 48. Policy & WasteReductionPolicy & Waste Reduction • Resource Conservation & Recovery Act 1976 • Superfund Act – 1980 – Identify hazardous waste dump sites – Protect groundwater in those areas – Clean up the sites – Find parties responsible & hold accountable – $750 billion bill for total project
- 49. Role of TechnologyRoleof Technology • Carrying capacity may be expanded through continuous technological innovation • Increase efficiency of energy & material use 2X double use or population without increasing impact • But with population growth predictions and necessary economic growth efficiency will have to increase 4X to 10X to compensate • Remember that sometimes technology itself can tax carrying capacity too
- 50. So how dowe assess the actualSo how do we assess the actual impact?impact? • Complete an Environmental Impact Assessment – A method of detailed survey required in some countries before initiating a major development – Independent of but paid for by the developer – Should include baseline study to measure environmental conditions before development begins – Identify areas of and species of conservation importance – Report produced is an environmental impact statement (EIS) called environmental management review in some countries – Monitoring then should continue after the development
- 51. Evaluate the useof EIS / EIAEvaluate the use of EIS / EIA • Advantages • Makes developer accountable for environmental effects • Makes efforts to mitigate / conserve habitats and species • Another hurdle to slow down development • Disadvantages • Subject to bias if funded by developer • Even with considerations it will never completely eliminate the impact
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