Environmental Studies Chapters 4-7 PDF

Environmental Studies Chapters 4-7 4.0 Food Security ================= - Many people in less-developed countries have health problems from not getting enough food, while many people in more-developed countries suffer health problems from eating too much. - **Food security:** all or mo...

Environmental Studies Chapters 4-7 4.0 Food Security ================= - Many people in less-developed countries have health problems from not getting enough food, while many people in more-developed countries suffer health problems from eating too much. - **Food security:** all or most people in a country have daily access to enough nutritious food to lead active and healthy lives - **Food insecurity:** chronic hunger and poor nutrition - **Causes**: political upheaval, war, corruption, and bad weather - Many people suffer from chronic hunger and malnutrition - **Macronutrients** - Carbohydrates - Proteins - Fats - **Micronutrients** - Vitamins - Minerals - **Chronic undernutrition:** not enough food to meet basic energy needs - **Chronic malnutrition:** not enough protein or other key nutrients - **Famine:** severe shortage of food - Result in mass starvation, many deaths, economic chaos, and social disruption - Many people do not get enough vitamins and minerals - Most often vitamins and mineral deficiencies in people in less-developed countries - **Iron** - Anemia - **Iodine** - Essential for thyroid function - Goiters - Many people have health problems from eating too much **(overnutrition)** - Similar health problems to those who are underfed - Lower life expectancy - Greater susceptibility to disease and illness - Lower productivity and life quality **Key Trends** 1. **Larger farms, fewer and older farmers** 2. **Changing biotechnology** 3. **Depopulation and demise of rural towns** 4. **Marketing of grain by farmers with the demise of the Canadian Wheat Board** - From 1935-2011, Prairie wheat farmers could only sell crops to the Canadian Wheat Board (CWB) - Some argue that farmers can get better prices on open markets; others believe they will be at mercy of railways and international grain companies - Prairies are on the northern margin of crop agriculture where growing season is short - Risk of prairie farmer is high compared to that of the southern Ontario farmer - **Agricultural regions:** 1. **Fertile Belt** (grasses are higher, organic) 2. **Dry Belt** (grasses are shorter, prone to draught) 3. **Agricultural Fringe** (shorter growing seasons, higher latitudes) 4. **Peace River Country** **Canada: Agricultural Soil** - Southern Ontario is not blessed with an abundance of natural resources. - Its main primary industry takes advantage of the region's two main environmental attributes: **its fertile soils and its favorable climate.** - **Southern Ontario** has over half of the highest quality agricultural land **(Class 1)**. - **Urban Sprawl --** between 1976 to 2006, nearly 200,000 acres have been lost. - Land for growing vegetables or raising cattle might fetch \$2,000 an acre, developers are ready to offer farmers \$40,000 an acre, knowing they can flip it for twice that when the property becomes part of a new subdivision. - **Agribusiness** - Average farmer (America) feeds 129 people - Annual sales greater than auto, steel, and housing combined - **Food production -- very efficient** - Americans spend 10% of income on food - **Hidden costs of subsidies and costs of pollution and environmental degradation** - Industrialized food production requires huge inputs of energy - Agriculture uses 20% of all energy use - **Mostly nonrenewable energy** -- oil and natural gas - **(Dr. Norman E. Borlaug) Green Revolution**: increased crop yields, decreases poverty and malnutrition 1. **Monocultures of high-yield key crops** 2. **Large amounts of fertilizers, pesticides, and water** 3. **Multiple cropping** - **Second Green Revolution** - Fast growing dwarf varieties - World grain has tripled in production - There are limits to the expansion of the **Green Revolution** - **Usually requires large inputs of fertilizers, pesticides, and water** - **Often too expensive for many farmers** - Crossbreeding/genetic engineering produce new varieties of crops/livestock - **First gene revolution** - **Crossbreeding through artificial selection** - **Slow process** - **Amazing results** - **Genetic engineering -- second gene revolution** - **Alter organism's DNA** - **Genetically Modified Organisms (GMOs) - transgenic organisms** - **Reduces the amount of biodiversity** - Animals for meat are raised in: - **Pastures and rangelands** - **Feedlots** - Meat production increased more than sixfold between 1950 and 2010 - **Increased demand for grain** - **Demand is expected to go higher** - Industrialized meat production has harmful environmental consequences - **Pros:** - **Increased meat supply** - **Reduced overgrazing** - **Kept food prices down** - **Cons:** - **Uses large amounts of water** - **Harmful environmental costs** - Fish and shellfish production has increased dramatically - **Fishery:** - **The concentration of a particular species suitable for commercial harvesting** - 30% are overfished - 57% harvested at full capacity - **Aquaculture, blue revolution:** - World\'s fastest-growing type of food production - Dominated by operations that raise herbivorous species - Aquaculture can harm aquatic ecosystems - Several environmental problems - Fish are caught to feed to other fish - **Inefficient process** - **Environmental toxins** - Spread invasive plant species - Fish farms produce waste **Biodiversity Loss** - Loss and degradation of grasslands, forests, and wetlands in cultivated areas - Fish kills from pesticide runoff - Killing wild predators to protect livestock - Loss of genetic diversity of wild crop strains replaced by monoculture strains **Soil** - Erosion - Loss of fertility - Salinization - Waterlogging - Desertification - Increased acidity **Soil Erosion** - **Movement of soil by wind and water** - Natural causes and human causes **Two major harmful effects of soil erosion:** - **Loss of soil fertility** - **Water pollution** **Desertification** - Productive potential of topsoil falls by 10% or more - Prolonged drought, human activities - Human agriculture accelerates desertification - Dust bowl - **Severe wind erosion of topsoil** **Air Pollution** - Greenhouse gas emissions and pollutants from fossil fuel use - Pollution from pesticide sprays - Cleaning and burning of forests for croplands - One-fourth of all human-generates greenhouse gases - Livestock contributes 18% of gases - **Methane in cow belches** **Water** - Water waste - Aquifer depletion - Increased runoff, sediment pollution, and flooding from cleared land - Pollution from pesticides and fertilizers - Algal blooms and fish kill in lakes and rivers caused by runoff of fertilizers and agricultural wastes **Human health** - Nitrates in drinking water (blue baby) - Pesticide residues in drinking water, food, and air - Contamination of drinking and swimming water from livestock wastes - Bacterial contamination of meat **What options do we have to increase production?** - Modifying crop genetics - Expanding the green revolution - Changing land usage - Changing eating habits and food waste **We can produce food more sustainably by:** - Using resources more efficiently - Sharply decreasing the harmful environmental effects of industrialized food production - Eliminating government subsidies that promote such harmful impacts **What Can You Do?** - Eat less meat, no meat, or orga nically certified meat - Choose sustainably produced herbivorous fish - Use organic farming to grow your food - Buy certified organic food - Compost food wastes 5.0 extinctions =============== - The sudden loss of large numbers of species of plants and animals - Coincide with boundaries of geologic periods or epochs - Most hypotheses to explain mass extinctions involve rapid climate change caused by - **Plate tectonics** - Create new patterns of ocean circulation - **Volcanic activity** - Large eruptions release huge quantities of carbon dioxide, warming climate - Some eruptions release ash and Sulphur Dioxide, cooling climate - **Extraterrestrial impacts** - Release of dust blocks solar radiation - Geologists have documented five major mass extinctions during the past 550 million years 1. **The first extinction could have been caused by global cooling followed by rapid warming (446 million years ago)** 2. **The Late Devonian mass extinction (365 million years ago) Life in shallow seas were the worst affected.** 3. **The Permian mass extinction (250 million years ago) - The Great Dying.** **4. The fifth extinction (Triassic-Jurassic mass extinction) is linked to climate change and volcanism (200 million years ago)** **5. The fifth extinction coincides with the end of the Cretaceous Period and the K-T boundary** - 65 million years ago - Caused by the impact of a large asteroid - Brought an end to the large dinosaurs - The letter K is used because Cretaceous is spelled with a K in some languages **Anthropocene** - Species are becoming extinct 100 to 1,000 times faster than they were before modern humans arrived on earth - By the end of this century, the extinction rate is expected to be 10,000 times higher than that background rate - **The sixth major mass extinction is occurring today** **is occurring today due to increases in human population, deforestation, agriculture, overfishing, and pollution** - Extinctions are natural but sometimes they increase sharply - **Biological Extinction** - No species member alive - **Trophic Cascade** - Population declines or extinctions among connected species - **Mass Extinction** - Many species in a short amount of time **Extinct animals** - The Dodo, Baiji White Dolphin, Pyrenean Ibex, Passenger Pigeon, Steller's Sea Cow, West African Black Rhino, and Tasmanian Tiger - Endangered and threatened species are ecological smoke alarms - **Regionally extinct** - In areas a species is normally found - **Functionally extinct** - To the point at which species can no longer play a functional role in the ecosystem - **Endangered species** - So, few members that the species could soon become extinct - **Threatened species (vulnerable species)** - Still enough members to survive, but numbers declining - May soon be endangered - **The greatest threats to any species are:** 1. **Habitat destruction, degradation, and fragmentation** 2. **Invasive (nonnative) species** 3. **Population and resource use growth** 4. **Pollution** 5. **Climate change** 6. **Overexploitation** - Loss of habitat is the greatest threat to species (HIPPCO) - **Where have all the honeybees gone?** - Bees play a key role in pollination - Globally, about one third of the food supply comes from insect-pollinated plants - Currently, agriculture depends heavily on a single species of bee - Suffering from Colony Collapse Disorder - Each year, 30-50% of colonies in Europe and the U.S. - **Why should we care about the rising rate of species extinction?** - We should avoid speeding up the extinction of wild species because: - Of the ecosystem and economic services, they provide: 1. **Plants for food, fuel, lumber, and medicine** 2. **Ecotourism** - It can take millions of years for nature to recover from large-scale extinctions - **It will take 5-10 million years to regain species biodiversity after this century's extinctions** - Many people believe that species have a right to exist regardless of their usefulness to us - Illegal killing, capturing, and selling of wild species threatens biodiversity - **Poaching and smuggling of animals and plants** - **Animal parts** - **Pets** - **Plants for landscaping and enjoyment** - **Prevention** - **Research and education** - **A rising demand for bushmeat threatens some African species** - West and Central Africa wild animals - **Supply major cities with exotic meats** - Hunting has driven species to extinction - **Miss Waldron's red colobus monkey** - Threatened species: - **Monkeys, apes, antelope, elephants, and hippos** - **A disturbing message from the birds** - 70% of the world's bird species are declining - Habitat loss and fragmentation of the birds' breeding habitats - Forests cleared for farms, lumber plantations, roads, and development - Intentional or accidental introduction of nonnative species - These species eat the birds - Exposure to pesticides - Overexploitation - For pets - **Birds are indicator species** - **Respond quickly to environmental changes** - Birds perform critical ecosystem and economic services - Extinctions could affect many other species - We can reduce species extinction and sustain ecosystem services by: - Establishing and enforcing national environmental laws and international treaties - Creating protected wildlife sanctuaries - Taking precautionary measures to prevent such harm - **1975: Convention on International Trades in Endangered Species (CITIES)** - Signed by 172 countries - **Convention on Biological Diversity (BCD)** - Focuses on ecosystems - Ratified by 190 countries (minus the U.S.) - **We can establish wildlife refuges and other protected areas** - **Point Pelee National Park** - **Wildlife Preserve** - In 1903, Theodore Roosevelt established the first federal wildlife refuge - Pelican Island, Florida - **Wildlife refuges and preserves** - Most are wetland sanctuaries - Most needed for endangered plants - Seed banks, botanical gardens, and wildlife farms can help protect species 1. **Seed Banks** - **Preserve genetic material of endangered plants** 2. **Botanical Gardens and Arboreta** - **Living plants** 3. **Farms can raise organisms for commercial sale** - Zoos and aquariums can protect some species - **Techniques for preserving endangered terrestrial species:** 1. **Egg pulling** 2. **Captive breeding** 3. **Artificial insemination** 4. **Embryo transfer** 5. **Use of incubators** 6. **Cross-fostering** - Goals of ultimately releasing/reintroducing populations to the wild - Limited space and funds - We are hastening the extinction of wild species and degrading the ecosystem services they provide by: - **Destroying and degrading habitats** - **Introducing harmful invasive species** - **Increasing human population growth, pollution, climate change, and overexploitation** - We should avoid causing the extinction of wild species - Species provide vital ecosystem and economic services - Their existence should not depend primarily on their usefulness to us - We can work to prevent the extinction of species and to protect overall biodiversity and ecosystem services by: - **Using laws and treaties** - **Protecting wildlife sanctuaries** - **Making greater use of the precautionary principle** 6.0 What are solid and hazardous wastes ======================================= - We throw away huge amounts of useful things: - **Solid waste** - **Industrial solid waste** - **Mines, farms, industries** - **Municipal Solid Waste (MSW)** - Waste ends up in rivers, lakes, the ocean, and natural landscapes - Hazardous waste is a serious and growing problem - **Hazardous waste (toxic waste)** - Threatens human health of the environment - **Classes of hazardous waste:** - **Organic compound** - **Toxic heavy metals** - **Radioactive waste** - **Municipal solid waste** - 338 kg of garbage produced per person - Waste management costs \$1.5 billion - E-waste growing rapidly (140 000 Tonnes) - **Electronic waste (e-waste) is the fastest growing solid waste problem** - Most ends up in landfills and incinerators - **Composition includes:** - **High quality plastics** - **Valuable metals** - **Toxic and hazardous pollutants** - Shipped to other countries - **International Basel Convention:** bans transferring hazardous wastes from developed countries to developing countries - European Union - **Cradle-to-grave approach** - **Toronto\'s garbage problem** - Began transporting garbage to Michigan after a failed attempt to truck waste to an abandoned mine near Kirkland Lake - **What does it mean to live in a high-waste society?** - Wasting valuable resources - **North Americans spend more \$\$\$ on trash bags than 90 other countries spend for everything** - Each year we throw away: - **670 000 Tonnes of edible food** - **186 billion pieces of junk mail** - **50 million computers** - **Waste management** - **High-waste approach** - Burying, burning, shipping - **Waste reduction** - **Low-waste approach** - Refuse, reduce, reuse, recycle, rethink, and recover - **Integrated waste management** - Uses a variety of strategies - Can we cut solid waste by refusing, reducing, reusing, and recycling? - Waste reduction is based on: - **Refuse -- don't use it** - **Reduce -- use less** - **Reuse -- use it over and over** - **Recycle** - **Composting** - Using bacteria to decompose biodegradable waste - There is great potential for recycling - **Primary, closed-loop recycling** - **Materials recycled into same type** - **Secondary recycling** - **Materials converted to other products: tires** - **Types of wastes that can be recycled:** - **Pre-consumer:** internal waste generated in manufacturing process - **Postconsumer:** external waste generated by product use - We can mix or separate household solid wastes for recycling - **Materials-Recovery Facilities (MRFs)** - Can encourage increased trash production - **Source separation:** - **Pay-as-you-throw** - **Fee-per-bag** **Recycling paper** - **Production of paper versus recycled paper:** - **Energy use -- world\'s fifth largest consumer** - **Waste use** - **Pollution** - **Easy to recycle:** - **Uses 64% less energy** - **Produces 35% less water pollution** - **Produces 74% less air pollution** **Recycling Plastics** - **Plastics** - Composed of resins created from oil and natural gas - Currently only 7% is recycled in the U.S. - **Many types of plastic resins** - **Difficult to separate** **Burning** - **Waste-to-energy incinerators** - To heat water or produce electricity - **Landfills emit more air pollutions than modern waste-to-energy incinerators** - Toxic chemicals that are filtered must be disposed of or stored **Burying** - **Sanitary landfills** - Compacted layers of waste between clay or foam - Bottom liners; containment systems - **Open dumps** - Widely used in less-developed countries - Rare in developed countries - Large pit - Sometimes garbage is burned **Sanitary landfills advantages** - Low operating costs - Can handle large amounts of waste - Filled land can be used for other purposes - No shortage of landfill space in many areas **Sanitary landfills disadvantages** - Noise, traffic, and dust - Releases greenhouse gases unless they are collected - Output approach that encourages waste production - Eventually leaks and can contaminate groundwater **How can we remove or detoxify hazardous waste?** - **Physical methods** - Distillation, filtration, precipitation - **Chemical methods** - **Bioremediation** - Using bacteria or enzymes - **Phytoremediation** - Using plants or algae **Surface impoundments advantages** - Low costs - Can be built quickly - Wastes can often be retrieved - Can store wastes indefinitely with secure double liners **Surface impoundments disadvantages** - Groundwater contamination from leaking liners or overflow from flooding - Air pollution from volatile organic compounds - Disruption and leakage from earthquakes - Output approach that encourages waste production 7.0 Air Pollution ================= **The South Asian Brown Clouds** - A stretch across most of India, Bangladesh, China, and the western Pacific Ocean **Air pollution connects the world** - Pollutants can circle the globe in about two weeks - Stricter air pollution standards and cleaner fuels are needed - **Troposphere** - **75-80% of Earth's air mass** - Closest to Earth's surface - Composition of gases **(78% nitrogen and 21% oxygen)** - Rising and falling air currents and greenhouse gases play a major role in weather and climate - **Stratosphere** - Similar composition to the troposphere except that it contains: - Less water - **Ozone layer (O~3)~:** filters 95% of harmful UV radiation and allows life to exist - **Air pollution: presence of chemicals in the atmosphere** - Concentrations high enough to harm organisms, ecosystems, human-made materials, and to alter climate - **Natural sources:** - Dust blown by wind - Pollutants from wildfires and volcanoes - Vaporous organics released by plant - **Human sources: organics (plants)** - **Stationary sources: power plants and industrial facilities** - **Mobile sources: motor vehicles** - **Primary pollutants** - Emitted directly into the air - **Secondary pollutants** - From reactions of primary pollutants **Acid rain** - Caused mainly by coal-burning power plants and motor vehicle emissions - Threatens human health, aquatic life and ecosystems, forests, and human-built structures in some regions - **Acid deposition** - Sulfuric acid and nitric acid compounds - **Wet deposition:** rain, snow, fog, and cloud vapor - **Dry deposition:** particles - Substances remain in the atmosphere for 2-14 days - Human health (respiratory disorders; toxins from fish) - Release of toxic metals - Aquatic ecosystems (lowers pH balance and kills organisms) - Leaching of soil nutrients - Forest and building damage **Acid deposition prevention** - Reduce coal use and burn only low-sulfur coal - Use natural gas and renewable energy resources in place of coal - Tax **sulfur dioxide (SO₂)** emissions **Acid deposition cleanup** - Add lime and phosphate fertilizer to neutralize acidified lakes - Add lime to neutralize acidified soils - Pollutants mix in the air to form industrial smog - Primarily because of burning coal and photochemical smog - Caused by emission from motor vehicles, industrial facilities, and power plants **Transboundary Air Pollution** - **1980s:** U.S. sulfur dioxide (SO₂) emissions acidified Canadian lakes and forests - **1985:** U.S. took no action; Canada reduced emissions - **1990:** U.S. **Clean Air Act** amended to reduce sulfur dioxide (SO₂) emissions - **1991:** Canada -- U.S. Air Quality agreement - **Present day:** U.S. still produces 90% of transboundary emissions - **Temperature Inversion -- Mexico City** - **In developing countries** - Indoor burning of wood, charcoal, dung, crop residues, coal - Greatest risk to low-income populations - **In developed countries** - Indoor air pollution is greater than outdoor air pollution - Chemicals used in building materials - **Four most dangerous indoor air pollutants in more developed countries** 1. **Tobacco smoke** 2. **Formaldehyde** 3. **Radioactive radon-222 gas** 4. **Very small (ultrafine) particles** - Other indoor pollutants - Pesticide residues, lead particles, air-born spores **(mold, mildew)** **Radioactive radon-222** - Lung cancer threat - Occurs in certain areas based on geology - Associated with uranium and organic material in rock - **Air pollution can contribute to:** - Asthma - Chronic bronchitis - Emphysema - Lung cancer - Heart attack - Stroke **Stationary sources:** **Reduction or disposal** - Disperse emissions with tall smokestacks - Remove pollutants form smokestack gases - Tax each unit of pollution produced **Prevention** - Burn low-sulfur coal or remove sulfur from coal - Convert coal to a liquid or gaseous fuel - Phrase out coal use **Indoor pollution:** **Cleanup or dilution** - Use adjustable fresh air vents for workspaces - Increase intake of outside air - Circulate air more frequently - Circulate a building's air through rooftop greenhouses - Use efficient systems for wood-burning stoves **Prevention** - Ban indoor smoking - Cover ceiling tiles and lining of AC ducts to prevent release of mineral fibres - Set stricter formaldehyde emissions standards for carpet, furniture, and building materials - Prevent radon infiltration - Use less polluting cleaning agents, paints, and other products