14_env - 1 2 People & The Environment Like all...

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Unformatted text preview: 1 2 People & The Environment Like all living things, people interact with their environment. Unlike other living things, we have the ability to radically alter our environment We can choose how we will affect the natural world — constructively or destructively. Resource Issues Source: http://www.nmenv.state.nm.us/gwb/pps.html 3 Resources 4 A resource is a substance in the environment that is useful to people, is economically and technologically feasible to access, and is socially acceptable to use. There are two basic categories of resources: renewable and non-renewable. If they are mismanaged or wasted, renewable resources can be made non-renewable. Solutions? – Renewable resources – like fertile soil, trees, fish – can be used without being used up – they can renew themselves (in a reasonable period of time). – Non-renewable resources – like oil and minerals – can be exhausted. Once they are used, they’re gone. 5 Energy: Consumption The Tragedy of the Commons – Legal (policing); – Moral (shame); – Structural (privatize). 6 Per Capita Energy Consumption About ¼ of the world’s population live in MDCs – and consume about ½ of all the world’s energy. The US has 5% of the world’s population and consumes nearly ¼ of the world’s energy. In the US energy is consumed by – BUSINESS: Mostly electricity, and mostly from coal, followed by natural gas and oil. – HOMES: Mostly for heating, and mostly from natural gas, followed by coal and oil. – TRANSPORTATION: Almost all transportation energy today comes from oil. 1 U.S. Energy Consumption 1850–2005 7 8 Energy: Fossil Fuels In the late 1800s coal became more important than wood or other biomass fuels in the MDCs. Oil became the most important source of power in the 20th Century. Fossil fuels have two important characteristics: – The supply is finite. – The supply is unevenly distributed. 9 Reserves vs. Production: COAL 10 Proven Coal Reserves, 2006 Total Proven reserves: 909,064 million tonnes Major Proven Reserves: – US (27%) – Russia (17%) – China (12%) Annual global production: 3,080 million tonnes Major Consumers (million tonnes oil equivalent): – – – – – China 1,191 (39%) US 567 (18%) India 238 (8%) Russia 113 (4%) South Africa 94 (3%) Data from the BP Statistical Review of World Energy, June 2007. See http://www.bp.com/genericsection.do?categoryId=92&contentId=7005893 Chart from the BP Statistical Review of World Energy, 2007. See http://www.bp.com/sectiongenericarticle.do?categoryId=9010964&contentId=7021586 11 12 Reserves vs. Production: OIL Proven Oil Reserves, 2006 Total proven reserves: 1,208.2 billion barrels Major Proven Reserves: – – – – – Saudi Arabia (22%) Iran (11%) Iraq (10%) United Arab Emirates (8%) Kuwait (8%) Daily global production: 81,663 thousand barrels Major Consumers: – – – – – – US (24%) China (9%) Japan (6%) Germany (3%) India (3%) South Korea (3%) Data from the BP Statistical Review of World Energy, June 2005. See http://www.bp.com/genericsection.do?categoryId=92&contentId=7005893 Chart from the BP Statistical Review of World Energy, 2007. See http://www.bp.com/sectiongenericarticle.do?categoryId=9010943&contentId=7021566 2 13 Proven Reserves: 1986, 1996, 2006 14 Oil Imports & Exports, 2006 Chart from the BP Statistical Review of World Energy, 2007. See http://www.bp.com/sectiongenericarticle.do?categoryId=9010943&contentId=7021566 From the BP Statistical Review of World Energy, 2007. See http://www.bp.com/sectiongenericarticle.do?categoryId=9010943&contentId=7021566 15 16 Per Capita Oil Consumption, 2006 Reserves vs. Production: GAS Total proven reserves: 181.46 trillion cubic meters Major Proven Reserves: – – – – – – – Russia (26%) Iran (16%) Qatar (14%) Saudi Arabia (4%) United Arab Emirates (3%) US (3%) Nigeria (3%) Total global production: 2.6 trillion cubic meters Major Consumers: – – – – – – US (22%) Russia (15%) Iran (4%) UK (3%) Germany (3%) Japan (3%) From the BP Statistical Review of World Energy, 2007. See http://www.bp.com/sectiongenericarticle.do?categoryId=9010943&contentId=7021566 Data from the BP Statistical Review of World Energy, June 2005. See http://www.bp.com/genericsection.do?categoryId=92&contentId=7005893 17 18 Proven Reserves, Natural Gas 2006 From the BP Statistical Review of World Energy, 2007. See http://www.bp.com/sectiongenericarticle.do?categoryId=9010958&contentId=7021578 Per Capita Natural Gas Consumption, 2006 From the BP Statistical Review of World Energy, 2007. See 3 19 Natural Gas Imports & Exports, 2006 20 LNG The easiest way to transport natural gas is by pipeline – but when that’s not possible, it can be sent by tanker. Natural gas is liquefied by cooling it to -259˚F (-161˚C); it condenses to form a liquid with just 1/600th its original volume. When it reaches its destination the LNG is warmed and “regassified.” Unfortunately, this takes a lot of energy – making LNG less efficient and environmentally friendly than conventionally processed natural gas. There has never been a serious LNG tanker accident; however, there have been some accidents in the processing phases. From the BP Statistical Review of World Energy, 2007. See http://www.bp.com/sectiongenericarticle.do?categoryId=9010958&contentId=7021578 21 “Proven” vs. “Potential” Reserves Proven” Potential” Proven reserves can be measured with reasonable accuracy – we can be fairly confident about how much is available, and that it can be recovered economically. Potential reserves have not been discovered. So how do we know they exist? We don’t – but based on what we know about geology, technology, we can make a good guess about their existence. – Alternative fossil fuels (oil shale, tar sand, frozen methane) – Nuclear power (fission-based) Renewable (or inexhaustible) – Solar 22 Problems with Fossil Fuels – – – – Pollution Mine safety Subsidence & erosion Transportation Oil – – – – Air pollution Spills Dependence on foreign sources Transportation Natural Gas – Air pollution – Storage & safety – Transportation Source: http://www.bp.com/downloads.do?categoryId=9003093&contentId=7005944 Alternative Sources of Energy Non-Renewable Source: http://www.energy.ca.gov/lng/faq.html; http://www.energiacostaazul.com.mx/English/constructionupdate.htm; http://www.energy.ca.gov/lng/documents/costa_azul/2007-01-18_GOVERNORS_LNG_TASK_FORCE_BRIEFING.PDF Coal Source: http://www.eia.doe.gov/emeu/international/petroleu.html#Reserves 23 This is Sempra Energy’s new Energía Costa Azul facility near Ensenada, Mexico. It should begin operation soon, and can process one billion cubic feet/day. Other Renewable Energy Sources – – – – – – Wind Waves Hydroelectric Biomass Nuclear Fusion Others? • Passive • Active – Heat conversion – Indirect electric – Photovoltaic 24 Problems With Other Fossil Fuels Alternative fossil fuels have all the inherent problems of more conventional fossil fuels. They also have two major problems: – They are usually not economical to extract at current prices. – We aren’t sure how to extract or process them yet. Sources: http://www.eere.energy.gov/kids/roofus/solar_panels.html; http://ostseis.anl.gov/guide/oilshale/index.cfm; http://www.anl.gov/Media_Center/logos22-1/hydrogen.htm; http://www.epa.gov/cleanenergy/pdf/smith_may10.pdf 4 25 Problems with Nuclear Power 26 Nuclear Power Production 28 Nuclear Power in the U.S. Worldwide, nuclear power produces about 6% of the world’s electricity (the amount varies – 75% of the electricity in Lithuania and France comes from nuclear power). Nuclear power also varies in the US – 18 states have no nuclear power, but it supplies more than half the electricity in New Hampshire and Vermont) Problems with nuclear power: Chernobyl, Ukraine – – – – – Accidents Waste and waste storage Bomb material (nuclear and “dirty” bombs) Non-renewable – limited fuel supply High cost Source: http://www.hf.faa.gov/webtraining/Controls/ControlsFinal022.htm 27 Nuclear Energy Consumption, 2005 From the BP Statistical Review of World Energy, 2006. See http://www.bp.com/sectiongenericarticle.do?categoryId=9010966&contentId=7021588 29 Radioactive Waste 30 Current and Planned Low-Level Waste Disposal Radioactive waste may be either – Low-level (650,000 yd3/year) – High-level (more than 30,000 tons) Radioactive waste may be dangerous for literally thousands of years. There is, at present, no permanent waste disposal facility in the US. Yucca Mountain, NV Although the NRC review has not ended, as of today it appears the Yucca Mountain project is dead. http://www.ymp.gov/reference/photos/geology/page1.htm; http://www.state.nv.us/nucwaste/states/us.htm http://www.em.doe.gov/lowlevel/chap1.html 5 31 Problems with Renewable Energy Sources 32 Minerals are essential for an industrial society. Unfortunately, the earth’s crust is fairly miserly when it comes to the metals and other minerals – metallic and non-metallic – that we need. Remember that minerals are non-renewable – once they’re mined, they’re gone.* Solar, wind and wave power are dispersed – you need large areas and lots of machines to harness them – which raises costs. Hydroelectric and geothermal power can only be done in a limited number of places – and have serious environmental impacts. Biomass energy can cause pollution, and may cause a loss of food producing lands. Nuclear fusion sounds great – but it doesn’t work yet. 33 Cut-Off Grades for Ore Deposits Avg. Crust Abundance (%) Minimum Commercial Grade (%) 8.13% 30% 5.00% 25% 5.0 Manganese 0.10% 35% 350 Metal Chromium 0.02% 30% 1500 Nickel 0.008% 1.5% 188 Zinc 0.008% 4% 500 Copper 0.007% 1% 140 Silver 0.00001% 500 g/t 5000 Gold 35 Ferrous Minerals 3.7 Iron 34 *Unless they’re recycled! Concentration Factor Aluminum Mineral Resources 0.0000005% 5 g/t 1000 Nonferrous Metal Production Nonferrous metals are basically all metals that aren’t involved in iron and steel production (including precious metals like gold and silver). “Ferrous” minerals include iron and all the various alloy metals (chromium, manganese, etc.) that are used in steel making. 36 US Nonmetallic Mineral Production Principal US States for production of selected nonmetallic minerals. Note that some nonmetallic minerals (crushed stone, Portland cement, lime, sand and gravel, etc.) are produced just about everywhere! 6 37 Pollution 38 When more waste is added than a resource can accommodate, we have pollution. Not all pollution is caused by people; however, until we can control volcanoes, we are going to worry about the things we are responsible for: We can talk about air pollution in terms of three scales: global, regional and local. Global air pollution problems: – Global warming – Ozone damage – Air pollution – Water pollution – Land pollution (waste disposal) Regional air pollution problems: – Acid deposition When it comes to managing pollution there are two types of sources: point and non-point. Point are far easier to control. 39 41 Global-Scale Air Pollution: GlobalClimate Change There is no question that earth’s climate has changed over time There is also no question that people have been adding large quantities of certain gases and particles to atmosphere for the past 250 years. The question is: Does what we do seriously affect the earth’s climate? Greenhouse Gasses There are a lot of gases that are good at holding in the heat: – – – – H2O (Water vapor) CO2 (Carbon dioxide) CH4 (Methane) N2O (Nitrous oxide) These are all gasses that we have been putting into the atmosphere. Air Pollution Local air pollution problems: – Smog 40 Factors Affecting Climate Change Greenhouse Gasses (CO2, CH4, etc.) Atmospheric aerosols (soot, dust) Cloud changes Land cover changes Variations in the sun’s output Volcanic aerosols 42 Our Contribution “Since the beginning of the industrial revolution, atmospheric concentrations of carbon dioxide have increased nearly 30%, methane concentrations have more than doubled, and nitrous oxide concentrations have risen by about 15%.” Environmental Protection Agency “The observed patterns of [climate] change over the past 50 years cannot be explained by natural processes alone.” US Climate Change Science Program Sources: http://www.epa.gov/globalwarming/climate/index.html; http://www.climatescience.gov/Library/pressreleases/pressrelease2may2006.htm 7 43 Per Capita CO2 Production 2005 44 Not all the evidence clearly points to global warming. There are contradictory news story almost every day. All we can do is take the best evidence we can get, listen to the most reliable sources, and try to make the most prudent decisions. • The top 5 producers of CO2 (per 1,000 people, in metric tons): – – – – – Qatar UAE Kuwait Bahrain US 40.7 28.2 25.0 20.0 19.5 But Isn’t There Controversy? CO2 production, per 1,000, in metric tons. Source: http://www.nationmaster.com/ ; Data source: Secretariat of the UN Framework Convention on Climate Change (UNFCCC). 45 46 Sometimes the research is serious, sometimes it seems silly. Chacaltaya: End of a Glacier More information Source: http://news.bbc.co.uk/2/hi/americas/6496429.stm; http://www.miamiherald.com/news/americas/story/1030126.html; http://www.nytimes.com/2007/02/02/world/americas/02bolivia.html?_r=1 47 Warming of the climate system is “unequivocal.” For the next two decades temperatures will rise by 0.2˚C, with continued rising through the end of the century. A total rise in global average temperatures of about 2.0˚C4.5˚C (3.6 - 8.1°F) is likely. Predicted sea level rise is 0.30.8m (11.8-31.5 in). Snow cover at the global scale is predicted to contract, with widespread thawing of permafrost. Mmidlatitude and tropical storm tracks are predicted to move poleward. Precipitation may increase at higher latitudes and decrease in the subtropics. Climate changes will persist for centuries. Highlights from the IPCC 2007 Summary for Policymakers 48 Global-Scale Air Pollution: Ozone GlobalOxygen makes up about 21% of the atmosphere. Most of the time, atmospheric oxygen atoms travel in pairs — as O2 molecules molecules However, oxygen in the atmosphere can exist in another form — as O3 or ozone. Source: http://uarsfot08.gsfc.nasa.gov/HP_THEME/Ozone_Topic/Stat_Ozone_Loss(nat) Source: http://www.ipcc.ch/ 8 49 Ozone Is Not “Just Oxygen!” 50 Ozone is more chemically active than oxygen. Ozone is a pale blue gas. Ozone has a distinctive smell. Ozone has the ability to absorb/block ultraviolet light. Ozone is an extremely poisonous, corrosive gas (and has been used as a disinfectant, in water purification, and as a bleach) that damages and kills vegetation. In the stratosphere, ozone is vital to our planet’s survival. In the upper atmosphere, ozone is produced by a natural process and forms a layer that protects us from ultraviolet radiation. At ground level, ozone is a dangerous pollutant (part of smog). Source: http://www.epa.gov/oar/oaqps/gooduphigh/ 51 Making Good Ozone… 52 …And Making It Better Source: http://www.meto.umd.edu/~bruce/m1239702.html Source: http://www.meto.umd.edu/~bruce/m1239702.html 53 54 The Problem: CFCs and Friends A variety of humancreated chemicals, including solvents, packaging materials, industrial cleaners, and fire extinguishers, contain chlorofluorocarbons (CFCs) or related chemicals (HCFCs, carbon tetrachloride, methyl chloroform, etc.). When CFCs interact with ozone in the stratosphere, the results aren’t pretty Source: http://www.epa.gov/oar/oaqps/gooduphigh/ Breaking Up Is Hard ... 1 2 3 4 Source: http://www.meto.umd.edu/~bruce/m1239702.html 9 55 … And It Keeps Getting Worse 5 Cold Clouds During winter stratospheric winds form a vortex around the South Pole. Within the vortex the atmosphere over the pole is effectively isolated, temperatures are extremely cold (-80ºC), and unusual polar stratospheric clouds form. Chlorine from CFCs is stored on the clouds during the long polar night, and then released to attack ozone when the sun returns in spring. 6 Source: http://www.meto.umd.edu/~bruce/m1239702.html 57 56 The Results for the Planet Sources: http://svs.gsfc.nasa.gov/imagewall/solve.html; http://zebu.uoregon.edu/1997/ph161/l15.html ; htt // i / /004/004 l ht 58 Ozone Hole • Total Ozone Mapping Spectrometer (TOMS) on the Earth Probe satellite shows the growth of the ozone hole over 20 years. Image © 2004, NASA Source: http://www.floridatoday.com 59 Regional-Scale Air Pollution: RegionalAcid Precipitation http://ozonewatch.gsfc.nasa.gov/ 60 Acid Precipitation Damage Burning is a process of oxidation. Because all organic compounds contain (among other things) nitrogen and sulfur, oxides of nitrogen and oxides of sulfur are released into the atmosphere whenever we burn anything organic (wood, oil, etc.). These combine with atmospheric moisture to produce sulfuric and nitric acids — and can precipitate as acid rain or snow. Marble building ornaments, Philadelphia, showing effects of acid rain Acid precipitation affects some areas of the world far more than others — an effect of wind currents. The kinds of damage that can be done by acid rain vary from minor to disastrous. http://pubs.usgs.gov/gip/acidrain/2.html; http://pubs.usgs.gov/gip/acidrain/5.html 10 61 62 http://nadp.sws.uiuc.edu/isopleths/maps2000/ http://nadp.sws.uiuc.edu/isopleths/maps2000/ 63 64 Local-Scale Air Pollution: Smog LocalThere are really two kinds of smog: – Sulfurous – Photochemical Smog layer, upstate NY http://nadp.sws.uiuc.edu/isopleths/maps2000/ http://visibleearth.nasa.gov/cgi-bin/viewrecord?6626 Air Pollution: US Pollutants & Air Pollution Sources (percentages) 65 Source Particulates SO2 Photochemical smog is produced by the action of sunlight on atmospheric chemicals — mostly oxides of nitrogen and hydrocarbons (volatile organic compounds). One of the most dangerous compounds in photochemical smog is ozone. NOx VOC CO Lead Power 3% 87% 42% 5% 6% 13% Industry 2% 6% 3% 8% 4% 59% Solvents 0% 0% 0% 29% 0% 0% Storage 0% 0% 0% 7% 0% 0% Waste 1% 0% 0% 2% 1% 16% Vehicles 1% 1% 32% 30% 56% 0% Off-Highway 1% 5% 22% 14% 22% 13% Other 92% 0% 1% 4% 10% 66 Temperature Inversion Normally, air temperature declines with altitude. In a temperature inversion, cold air at the surface is trapped beneath a layer of warm air. Since cold air doesn’t rise, the air at the surface becomes stagnant. Any pollutants released into the surface air are trapped. 0% US Census Bureau, Statistical Abstract of the United States, 2000 http://www.airparif.asso.fr/english/prevision/inversionpollution.htm 11 67 Temperature Inversion: The Donora Valley 68 Water Pollution There are six types of water pollutants In October 1948, a temperature inversion in the town of Donora, PA trapped pollutants from nearby steel and zinc smelters. After 5 days, almost 6,000 people were severely ill. Twenty died. In 1950 President Harry Truman convened the first national air pollution conference, citing Donora as an example of the need. The kind of smog that caused the Donora Valley disaster is sometimes called a “sulfurous” smog (even though other chemicals, including fluorine, were involved). – – – – – – Biodegradable wastes (sewage) Plant nutrients (fertilizers, phosphates) Heat Sediments Hazardous and toxic chemicals (biocides) Radioactive wastes There are three main sources of water pollution – Water-using industries (mostly point source) – Municipal/sewage (point and non-point) – Agriculture (mostly non-point) http://www.epa.gov/region02/epa30/air.htm; http://www.smithsonianmag.si.edu/smithsonian/issues99/nov99/ 69 Industrial Water Pollution 70 Oil Spills About half the water used daily in the US is used by industry. Industrial activities routinely discharge a variety of chemicals (and heat) into our waters. Industrial pollutants include – PCBs (polychlorinated biphenyls) – Radioactive waste – Petrochemicals • In 1998 there were 8,315 recorded oil spills in US waters; over 885,000,000 gallons were spilled. • In 2000 the Bureau of Transportation Statistics recorded 8354 oil spills totaling 1,431,370 gallons. • In 2001 the US Coast Guard recorded 7,559 oil spills totaling 854,520 gallons, and 105 chemical spills totaling 271,429 gallons. 1 barrel of oil = 0.146 tonnes of oil – Thermal pollution 4,500,000 tonnes = 30,784,500 barrels http://elearningexamples.com/the-worst-oil-spills-in-history/ 71 Mining Acid mine drainage, Pennsylvania Rainwater reacts with mine waste to produce a variety of toxic pollutants Mine waste is a significant problem in many parts of the country – Kentucky, Tennessee and West Virginia (strip mining for coal) – Utah, Nevada, New Mexico (gold, silver, lead, copper, uranium mining) Cyanide sump pond, California Cyanide heap-leach mining for gold presents special problems in California and other western States. http://www.dep.state.pa.us/dep/deputate/minres/bamr/amd/science_of_amd.htm; http://www.epa.gov/region08/superfund/sites/co/svlpondpic.html 72 Municipal Water Pollution Cities produce an enormous variety of water pollutants – Street runoff – Salts, fertilizers, heavy metals, biocides – Sewage • Three kinds of sewage treatment – Primary (settling & skimming) – Secondary (aerobic decomposition) – Tertiary (chemical & biological purification) • About 78% of the US population is served by some kind of municipal wastewater treatment facility Sources: Statistical Abstract of the US, 2000; http://www.csc.noaa.gov/rvat/environ.html; http://css.snre.umich.edu/css_doc/CSS04-14.pdf 12 73 Agricultural Water Pollution 74 Biological Oxygen Demand When too great a quantity of plant nutrients get into the water, they can set off a series of steps that result in the biological death of a water body. Steps to oxygen depletion Agriculture is the leading source of non-point pollution in the US There are 3 main types of agricultural pollution – FERTILIZERS – BIOCIDES • Herbicides • Pesticides – ANIMAL WASTE – – – – Feedlot, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, Nebraska Excess nutrients Algal bloom and death Bacterial decomposition Oxygen depletion http://www.ars.usda.gov/is/AR/archive/oct98/odor1098.htm http://www.agnr.umd.edu/users/agron/nutrient/Factshee/Phosphorus/Eutrop.html 75 76 The Aral Sea: 1960s The Aral Sea: 1970s 1964 1973 http://edcwww.cr.usgs.gov/earthshots/slow/Aral/Aral http://edcwww.cr.usgs.gov/earthshots/slow/Aral/Aral 77 78 The Aral Sea: 1980s The Aral Sea: 1990s 1987 1999 http://edcwww.cr.usgs.gov/earthshots/slow/Aral/Aral http://edcwww.cr.usgs.gov/earthshots/slow/Aral/Aral 13 79 80 The Aral Sea: 2003 The Aral Sea Today As recently as the 1980s 60,000 people were employed in the Aral Sea fishing industry. Today, there is no commercial fishing in the area. Surface area is now less than 50% what it was in 1950; volume is less than 25%. Climate in the area has become more extreme; dust, contaminated with pesticides and heavy metals, is blown as far as Pakistan, China, and the Arctic. Kazakhstan and Uzbekistan signed treaties to try to save the Aral Sea in 1992 and 1994. The crisis continued. In 2003 the Kazakh government announced a plan to build a dam to raise the water level of the North Aral Sea and reduce its salinity; the South Aral Sea would be abandoned. Satellite image of the Aral Sea in the year 2003 http://news.bbc.co.uk/1/hi/sci/tech/3846843.stm 81 Saving the North, Killing the South 82 Land Pollution We could talk about a number of “land pollution” problems – loss of farmland; soil erosion; salinization, etc. Instead we are going to focus on one aspect of land pollution: solid waste disposal. In the summer of 2005 the Kok Aral dam, funded by the World Bank to save the northern part of the Aral Sea, was completed. Since then the northern region has started to fill up – and even more quickly than expected. – “Solid Waste” refers to trash and garbage — not sewage! Americans throw away more trash per person than any other people on earth — about 1,600 pounds per person, per year. http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17241 83 Municipal Solid Waste 2007 http://www.epa.gov/epawaste/nonhaz/municipal/pubs/msw07-fs.pdf 84 What’s in the trash? http://www.epa.gov/epawaste/nonhaz/municipal/pubs/msw07-fs.pdf 14 85 Methods of Waste Disposal 86 Dumps (the not sanitary landfills) There are four methods of solid waste disposal that are used today: – – – – DUMP (“landfill” – obsolete in the US) SANITARY LANDFILL INCINERATION RECYCLING A village dump in rural Alaska. Because the land here is frozen (permafrost), it is impossible to construct a landfill here. US Census Bureau, Statistical Abstract of the United States, 2000; http://roomfordebate.blogs.nytimes.com/2010/04/13/should-the-u-s-burn-or-bury-its-trash/ http://www.denali.gov/content/challenges/solid.htm 87 88 Dumps are pretty much self-explanatory – solid waste (trash) is just dumped. In most of the United States, dumps are now obsolete and illegal. In LDCs dumps are still common. Dumps are notorious for their stench, disease, and for attracting vermin. Sanitary Landfill Problems with Sanitary Landfills Leachate — liquid (from rain or other sources) reacts with solid waste to produce a toxic brew that can easily contaminate groundwater. Capacity — since the 1970s the number of landfills in the US has declined by 80%. NIMBY — “not-in-my-back-yard” The most common way to dispose of solid waste in the developed world today is in a sanitary landfill. Although a definite improvement on the old-fashioned dump, landfills have some serious problems. http://school.discovery.com/homeworkhelp/worldbook/atozpictures/lr000599.html 89 Sanitary Landfills: Declining Capacity 90 Incineration Incinerators can be designed to burn solid waste. In theory this turns a problem into an opportunity: – Waste can be burned to generate electricity. – The volume of waste can be reduced drastically (by up to 96%). – There were 86 waste-to-energy facilities in the US as of 2010, generating nearly 3,000 megawatt hours of electricity (about 1.5 times the amount produced by the San Onofre Nuclear Generating Station). http://www.epa.gov/epawaste/nonhaz/municipal/pubs/msw07-fs.pdf http://sofia.usgs.gov/publications/posters/merc_program/; http://news.cnet.com/Powering-cities-on-landfill-waste/2100-11392_3-6188867.html; http://www.wte.org; http://www.sce.com/PowerandEnvironment/PowerGeneration/ 15 91 Problems With Incineration 92 Products can be “recycled” in two ways: Air Pollution — the fumes produced by burning solid waste are highly toxic. Ash — although the volume of trash is reduced by up to 96%, the remaining ash is extremely toxic and highly concentrated, and must be disposed of — probably in a toxic waste landfill. 93 Recycling: Pick-Up, Processing, Pickand Re-Manufacturing ReRecyclables are collected in four methods – – – – Regardless of how they’re collected, recyclables are sold as commodities – scrap aluminum competes with “virgin” aluminum in the marketplace. 95 – – – – • When an aluminum can is recycled to produce another aluminum can, not only is pollution reduced, but the need for mining and manufacturing is reduced as well. – Recycling in a different production process • Not everything can be recycled – plastic bottles are not usually made into more bottles. • Instead, the bottles are used to make other plastic items – brooms, pails, etc. • This also reduces waste, and reduces the need for making plastics directly from petroleum. 94 “Biodiversity” is the variety of species – either at the global or local scale. It’s estimated that there are millions of undiscovered species still out there. Source: http://www.globalchange.umich.edu/globalchange2/current/lectures/biodiversity/biodiversity.html Sustainability Conservation: Sustainable use and management of natural resources. – Renewable resources are conserved if they are consumed at (or less than) replacement rate. – Non-Renewable resources are conserved if reserves are maintained for future generations. Paper Plastic Glass Aluminum Sustainable Development and Biodiversity “Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” If sustainable development is possible, then it is vital to maintain biodiversity. – Recycling in the same production system Once they’ve been prepared, recyclables are turned into new goods. Four recycled commodities account for more than half of all recycling: Deposit programs Drop-off centers Curbside programs Buy-back centers Reducing Pollution: Recycling Conservation is not the same as preservation. 96 Threats to Biodiversity – and Maybe to Us! Species die – that is natural and inevitable. But in the last few centuries, the rate of species extinction has increased enormously. Habitat destruction, especially in the tropics, is a very great concern. Tropical forests cover only 7% of the earth’s land, but are home more than 50% of all species of plants and animals! Source: http://www.globalchange.umich.edu/globalchange2/current/lectures/biodiversity/biodiversity.html 16 ...
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This note was uploaded on 12/16/2010 for the course GEOG 102 taught by Professor Osborn during the Fall '10 term at San Diego State.

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