Cities and Urban Environment Lecture Notes 2010

Cities and Urban Environment p.634-651 Urbanization = shift from countryside into towns and cities Suburbs = areas that are peripheral to and strongly influenced by cites Canada’s population is highly concentrated in the south. Two-thirds of Canadians live-in within 100km of southern border, occupying only about 4% of the land area of the country. Urban centers where populations, cultural activities, and political power are concentrated have been part of human culture for several thousand years. The difference in today’s urban centers is that they are unprecedented in scale and rate of growth i.e. human population growth has placed greater number of people into towns and cities compared to before. Mega-cites = 10millions or more people characterize much of the developing world; this is uncommon in North America. Metropolitan regions around Toronto combined are only 5.6million. Most fast growing cities in the world are in the developing world. Various factors influence the geography of urban areas. Location, climate, topography, configuration of waterways determine whether a small settlement will become a large city. Trading networks, funneling resources from agricultural regions, shipping products to other areas. Globalization has connected distant societies, and businesses and individuals can more easily communicate from locations away from major city centers. Therefore populations centers are able to decentralize in developed nations In North America also, shift of population from cities to suburbs is because of easier commute People have moved to suburbs Because want more less crowded, cleaner, cheaper real estate, less crime, and better schools However, more natural areas have disappeared as housing developments are constructed. Suburbians have to commute longer distances to work and spend more time in traffic Sprawl = the spread of low-density urban or suburban development outward from an urban center Today’s urban areas spread outward More space per person, so spatial growth > growth of number of people Sprawl = physical spread of development at a rate greater than the rate of population growth Sprawl has several causes 1) human population growth 2) per capital land consumption – each person takes up more land Highways and technologies fostered movement from city centers People like space and privacy, and dislike congestion What is wrong with sprawl? Transportation – sprawl constrains transportation options forcing people to drive cars making people dependent on nonrenewable petroleum economic and env consequences Pollution – sprawl’s effect on transportation gives rise to increased pollution ; CO2 emissions cause global climate change. Nitrogen and sulfur pollutants contribute to troposphere ozone, urban smog and acid precipitation. Motor oil and road salt pollute waterways risk to ecosystem and human health Health – sprawl promotes physical inactivity because driving cars instead of walking Obesity and high blood pressure. People from sprawling areas weight 2.7kg more Land use – the spread of low-density development means more land is developed while less is left as forests, fields, and farmland Less ecosystems services (habitat for wildlife, resource production, water cleansing) Economics – sprawl drains tax dollars from existing communities and funnels them into infrastructure for new development Instead of maintaining downtown, money spent on extending road system, water and sewer system, electricity grid, telephone lines, police and fire service etc. Creating Livable Cities City and regional planning are means for creating livable Planning = professional pursuit that attempts to design cities and other human settlements so as to maximize their efficiency, functionality, and beauty. City planners advice policy makers on development options, transportation needs, public parks, and other matters. Zoning is a key tool for planning Zoning = practice of classifying areas for different types of development and land use. Zoning can restrict areas to single use, as is often done with suburban residents tracts in so-called bedroom communities Mixed use = residential and commercial Zoning gives homebuyers and business owners security – know in advance what types of development can/cannot be located nearby ex. Industries Zoning involves government restriction on use of private land and represents a top-down constraint on personal property rights. Urban growth boundaries and greenbelts are now widely used Urban growth boundary (UGB) – line intended to separate areas designated to be urban from areas desired to remain rural Housing, commerce and industry encouraged to grow within these UGB but restricted elsewhere. Revitalize city centers, prevent urban sprawl, protect farmland, forests and open landscapes UGB reduce the $$ municipalities have to pay for infrastructure, compared to sprawl But UGB increases housing prices within their boundaries In Canada, UGB = greenbelts = like UGB, greenbelt is a land use or zoning designation that is intended to contain urban development while protecting natural or agricultural lands in surrounding areas. Greenbelt provides additional benefits: access to natural areas for city dwellers; better air and water quality; protection for plant and animal habitats. Toronto, Vancouver, Ottawa Smart growth aims to counter sprawl Building up, not out 10 principles - mix land uses; take advantage of compact building design and green buildings; crate a range of housing opportunities and choices; create walk able neighborhoods; foster distinctive, attractive communities with a strong sense of place; preserve open space, farmland, natural beauty, and critical environmental areas; strengthen and direct development towards existing communities; provide a variety of transportation choices; make development decisions predictable, fair and cost effective; encourage community and stakeholder collaboration in development decisions The “new urbanism” and “livable cities” are now in vogue UBG, greenbelt and smart growth = sustainable and more environmentally friendly urban environment Related movement among developers new urbanism = design neighborhoods on walk able scale, with homes, businesses, schools, and other amenities all close together for convenience – JANE JACOBS Transportation options are vital to livable cities Public buses, trains, subways, LRT – ease traffic congestion Parks and open space are key elements of livable cities Aesthetic purposes. Biophilia (our natural affinity for contact with other organisms). Also, these lands keep ecological processing functions by regulating climate, producing O2, filtering air and water pollutants, and providing habitat for wildlife Smaller public spaces are also important Large city parks = healthy urban environment Playgrounds, community gardens Greenways or corridors = strips of land that connection parks or neighborhoods, along rivers, provide network of walking trails, protect water quality, boost property values, serve as corridors of movement for birds and wildlife Urban Sustainability Urban resource consumption brings a mix of environmental impacts Resource sinks – need to import from beyond borders nearly everything to feed, clothe and house their inhabitants. Pull resources from countryside to cities. Large ecological footprint Efficiency – cites can help minimize per capita consumption by maximizing the efficiency of resource use and delivery of goods and services. Economy of proximity – it is simpler and cheaper to deliver goods and services to people who are clustered together, and it generates fewer environmental impacts More consumption Ecological footprints are greater than their actual land areas. Gha = global hectares are used for ecological footprint calculations to describe both area of biologically productive land or water, and the demand for it. Ex. Agricultural land is more biologically productive than pasture land. Therefore, global hectare for agricultural land will be physically smaller (i.e. less agricultural land needed to produce the same amount of productivity). Urban dweller has a larger footprint than rural dweller, because they are wealthier. Urban intensification preserves land because it prevents us from spreading across all over land, we are limited by things such as urban growth boundaries, so therefore, and wilderness and natural ecosystems are able to stay intact. Urban centers suffer and export pollution Cities import resources , but also export wastes – through pollution or trade Urban residents are exposed to heavy metals, industrial compounds and chemicals from manufactured products that accumulate in soil and water. Airborne pollutants cause photochemical smog, industrial smog, and acid precipitation. Fossil fuel combustion releases carbon dioxide and other pollutants, leading to climate change. Urban heat island effect = cities’ temperature is several degrees higher than surrounding suburbs and rural areas Due to heat-generating buildings, cars, factories, and people Dust dome = when heated air trapped in the city, the smog and air pollution also becomes trapped there Urban residents also suffer noise pollution (undesired ambient sound) and light pollutions Urban centers foster innovation and offer cultural resource – lead to solutions for environmental problems Some seek sustainability for cities Researchers in the field of URBAN ECOLOGY hold that cities can be viewed as ecosystems. Cities should follow ecoysystem-centerd model for urban sustainability and reducing environmental impact: Maximize efficient use of resources Recycle Develop environmentally friendly technologies Account fully for external costs Offer tax incentives to encourage sustainable practices Use locally produced resources Use organic waste and wastewater to restore soil fertility Encourage urban agriculture Environmental Policy: Decision Making and Problem Solving pgs. 690-717 Policy = formal set of general plans and principles intended to address problems and guide decision making in specific instances Public policy = policy made by governments; laws and regulations to advance societal welfare Environmental policy = policy that pertains to human interactions with the environment; aims to regulate resource use or reduce pollution to promote human welfare and/or protect natural systems Environmental policy addresses issues of equity and resource use Tragedy of the commons – Garrett Hardin, a resource held in common that is accessible to all and is unregulated will eventually become overused and degraded. Therefore, it is in our best interest to develop guidelines for the use o such resources. Free riders – another reason to develop policy for publicly held resources is the free rider problem. Factory example because others are taking care of reducing pollution, its okay for us to not to do the same. i.e. private voluntary efforts are less effective than efforts mandated by public policy External costs – environmental policy also ensures that some parties don’t use resources in ways to harm others i.e. openly dealing with external costs, such as water pollution downstream Many factors hinder implementation of environmental policy – short term gains, long process to get policies into affect Canadian Environmental Law and Policy Canada’s environmental policies are influenced by our neighbor NEPA in 1970 and EPA in U.S. Environment Canada in 1971 Several legal instruments are used to ensure that environmental goals are achieved Acts = laws or statutes proposed and voted upon by the Parliament of Canada or provincial/territorial parliaments Regulations = detailed set of requirements (numerical limits, licensing requirements, performance specifications, exemptions) established by governments to allow them to implement, enforce and achieve the objectives of environmental acts. Agreements = enforceable or voluntary; they are entered into by agencies of government in order to streamline the administration of environmental legislation Permits = documents that grant a group legal permission to carry out an activity, usually within certain limitations and time 4 basic ways to make people comply to environmental laws: Criminal enforcement Penalties or fees Administrative orders to investigate, clean up etc Civil actions i.e. lawsuits Environmental goals and best practices can be promoted by voluntary initiatives ex. Mining industry ISO = International Organization for Standardization – headquartered in Geneva, 157 nations – has voluntary guidelines Canadian environmental policy arises from all three levels of government Federal government Canadian Environmental Protection Act (CEPA) – 1999 ; preventing pollution and protecting environment Canadian Environmental Assessment Act – 1992 Requires any project involving federal funds to undergo EIA (environmental impact assessment) Fisheries Act – 1985 – prohibits release of dangerous substances into body of water which fish are present Transportation of Dangerous Goods – 1992 – regulates transport of hazardous materials including waste materials Canadian Wildlife Act – 1985 – Migratory Birds Act, Species at Risk Act Environment Canada, Health Canada, Natural Resources Canada, Fisheries and Oceans Canada, Indian and Northern Affairs, Transport Canada, Statistics Canada, Agri-Foods Canada, etc. all influence Environmental Policy and Management Provincial / territorial governments Require organizations to obtain permits Aboriginal governments – often involvement stems from land claims, desire to ensure adequate Aboriginal participation, ensuring equitable access to natural resources and preventing excessive exposure of Aboriginal communities to environmental degradation Municipal governments Management of water and sewage systems, land-use zoning, local air quality, waste disposal International agreements – ex. Can’t export elephant ivory because of agreement with UN Government and nongovernmental agencies work together to resolve environmental issues Public participation and consultation to environmental management is mandated by CEPA. It means that government does not undertake any major regions to policy without consultation with stake holders. Stakeholder = person or group with an interest in, or might be affected by, the outcome Individual citizen stakeholders in environmental policy development are often represented by environmental nongovernmental organizations (ENGOs) – Greenpeace, Sierra Club, etc. Different environmental media require different regulatory approaches Environmental law in Canada today is also influenced by history Ex. Water law has development from two different historical/legal concepts. Riparian law = anyone who has legal access to the water’s edge (such as owning property near river bank) has the legal right to withdraw water from the resource Prior appropriation = first come, first serve, one’s right to withdraw water is established by historical precedence Right to govern and allocation water and other natural resources was granted to provinces by the federal govt, but it still continues to play a role ex. In management of fisheries Environmental policy has changed with the society and the economy Social context for environmental policy changes over time Historians suggest that major advances in environmental policy occurred in the 1960s and 1970s because 3 factors converged. Evidence of environmental problems People could visualize policies to deal with the problems Political climate was ripe, with a supportive public and leaders willing to act Fourth reason economic confidence – life was reasonably comfortable in North America by 1960s and 1970s. Willingness-to-pay transition- financial sacrifices and behavioral changes. The concept of sustainable development now guides environmental policy International Environmental Law and Policy p.708 International law includes conventional and customary law Customary law arises from long-standing practices or customs held in common by most cultures Conventional law arises from conventions or treaties into which nations enter Ex. Montreal protocol of 1987, Kyoto Protocol aimed at reducing fossil fuel emission that contributes to global climate change. Several organizations shape international environmental policy UN – 1945, headquartered in Ney York City UNEP – U N Environmental Program created in 1972 to solve environmental problems, based in Nairobi, Kenya European Union (EU) World Trade Organization (WTO) – represents multinational corporations and promotes free trade, has real authority to impose financial penalties on nations (unlike UN and EU). OPEC – intergovernmental organization of oil-producing and exporting nations, with 13 members International ENGOs – Greenpeace, WWF for Nature Exploring Approaches to Environmental Policy Environmental policy that is mainly from regulatory or legislative perspective top-down From perspective of public awareness and grassroots environmental activism bottom-up Science plays a role in policy, but it can be politicized Command-and-control policy has improved our lives, but it’s not perfect Command-and-control – settings rules / limits and punishment for violating the rules Most of the environmental laws of recent decades have been enforced this way But it can fail when it can lead to unforeseen consequences Economic tools can also be used to achieve environmental goals Instead of command-and-control, crate economic incentives to encourage desired outcomes Subsidies = a government giveaway of cash or publically owned resources that is intended to encourage a particular activity Tax breaks for certain types of businesses Green taxes and “polluter pays” Green taxes – taxes on environmentally harmful activities and products Polluter pays principle – price of a good or service should include all its costs, including costs of environmental degradation that would otherwise be pass on as external cost Permit trading system – government creates a market in permits for an environmentally harmful activity, and companies, utilities, or industries are allowed to buy, sell or trade rights to conduct the activity Cap-and trade system: a polluting party that is able to reduce its pollution received credit for the amount it did not emit and can sell this credit to other parties Ex. Emissions trading system p.716 Market incentives are being tried widely on the local level. Ecolabelling gives some choice back to the consumer = serves to tell consumers which brands are environmentally benign (how products were grown, harvested or manufactured) Atmospheric Science and Air Pollution pgs. 405-439 Industrializing nations are suffering increasing air pollution China has some of the world’s worst air pollution. SO2 or NO2 emissions above WHO standards Synthetic chemicals deplete stratospheric ozone Thermosphere, Mesosphere, Stratosphere (ozone concentration), Troposphere (ozone concentration). Ozone is a pollutant in the troposphere, but it is a highly beneficial gas in the lower stratosphere. The ozone molecules absorb incoming UV radiation from sun, helping protect life on Earth’s surface 1960s CFCs (chlorofluorocarbons) mass produced depleting stratospheric ozone ozone hole 1985 over Antarctica announced. 1987 Montreal Protocol – 180 nations agreed to cut CFC production Acidic deposition is another transboundary pollution problem Acidic deposition = settling of acidic pollutants from atmosphere onto Earth’s surface Acidic precipitation (acid rain), fog, gasses Primarily due to sulfur dioxide and nitrogen oxides, largely through fossil fuel combustion by automobiles, industrial facilities, and electric utilities. Acids leach nutrients from topsoil, mobilizes toxic metal ions, which hinder water and nutrient uptake by plants, acidic water funs off from land into streams, rivers and lakes, kills fish, damages agricultural crops Atmospheric deposition = wet or dry deposition on land of wide variety of pollutants Acid deposition has not been reduced as much as scientists had hoped Indoor Air Pollution Indoor air (workplaces, school, homes) generally contains higher concentrations of pollutants than outdoor air Indoor air pollution in the developing world arises from fuel wood burning Particulate matter and chemical from wood and charcoal smoke primary health risks in developing world. In developed nations, top risks are cigarette smoke and radon (a naturally occurring radioactive gas). Second-hand smoke Toxic and carcinogenic compounds in tobacco smoke Many VOCs (volatile organic compounds) pollute indoor air – from plastics to oils to perfumes to paints, pesticides Living organisms can pollute indoor spaces – dust mites, animal dander, fungi, mold, mildew, bacteria We can reduce indoor air pollution – use low toxicity material, monitor air quality, keep rooms clean, provide ventilation Global Climate Change Climate = area’s long term atmospheric conditions, including temperature, moisture content, wind, precipitation, barometric pressure, solar radiation Weather specifies conditions at localized sites over hours or days, whereas climate describes conditions across broader regions over seasons Global climate change = trends and variations in Earth’s climate Global warming = increase in Earth’s average surface temperature; it is only one aspect of global climate change The Sun and atmosphere keep Earth warm Sun, atmosphere, and oceans influence Earth’s climate the most Sun supplies most of our planet’s energy. Earth’s atmosphere, clouds, land, water, absorbs 70% of incoming solar radiation and reflect 30% back into space. The reflectivity of a surface = albedo. Greenhouse gases warm the lower atmosphere Earth’s surface absorbs incoming short – wavelength solar radiation. Surface materials increase in temperature and emit infrared radiation i.e. long-wavelength radiation. Some of the gases in the lower atmosphere (troposphere) absorb this infrared radiation. Water vapor, ozone, carbon dioxide, nitrous oxide, methane, halocarbons (CFCs) Greenhouse gases / radiatively active gasses. After absorbing radiation emitted from the surface, greenhouse gasses reemit infrared energy of slightly different wavelengths. Some of this reemitted energy is lost to space, but some travels back downward, warming the troposphere greenhouse effect Greenhouse effect is a natural good phenomenon, but it’s the anthropogenic (human generated) contribution that is of concern. Carbon dioxide is the anthropogenic greenhouse gas of primary concern because of the quantity at which is released. Human activity has released carbon from sequestration in long-term reservoirs Human activity often accelerates the movement (or fluxes) of material form one reservoir to another. Carbon is stored (or sequestered) for long periods in the lithosphere. But we are extracting it in the form of fossil fuel. Other greenhouse gasses contribute to warming Methane – fossil fuel deposits, raising live stock, landfills, growing crops such as rice Nitrous oxides Ozone – it’s a UV filter in the stratosphere, but also a radiatively active gas, contributing to warming both near the surface and up in the stratosphere. Halocarbons – CFCs, HFCs Water vapor – but it is not contributing to climate change – positive and negative feedback cycles Radiative forcing expresses change in energy input over time Radiative forcing = amount of change in energy that a given factor causes Positive forcing warms the surface, negative forcing cools it. The atmosphere is not the only factor that influences climate Milankovitch cycles – changes in earth’s rotation and orbit around the sun; are sufficient enough to trigger long-term climate variations such as periodic episodes of glaciations and interglaciations Solar output – sun varies in amount of radiation it emits over short and long timescales Ocean absorption – ocean acts a sink, holds 50x as much carbon as the atmosphere and absorbs carbon dioxide from atmosphere. Positive feedback effect oceans water temperature is rising, so it can absorb lesser amounts of carbon dioxide, so unable to unable to slow down global warming Ocean circulation – ocean water exchanges lots of heat with atmosphere Ocean currents and climate interact through thermohaline circulation, a worldwide current system in which warmer, fresher water moves along the surface, and colder, saltier water (denser) moves deep beneath the surface. Fossil Fuels: Energy and Impacts p.461-494 Sources of Energy We use a variety of energy sources Fossil fuels – nonrenewable, when plants die and are preserved in sediments, they form highly combustible substances Nonrenewable: Crude oil, natural gas, coal, nuclear energy Renewable: biomass (energy stored in plant matter from photosynthesis), hydropower, solar, wind, geothermal, tidal and wave, chemical Fossil fuels are indeed fuels created from “fossils” Fossil fuels are produced only when organic material is broken down in an anaerobic environment Kerogen = oil precursor composed of organic matter over millions of years under bodies of water Geothermal heating acts on kerogen to create crude oil and natural gas. Natural gas can also be produced nearer the surface by anaerobic bacteria decomposition of organic matter Coal is formed when plant matter is compacted so tightly that there is little decomposition Fossil fuel reserves are unevenly distributed 2/3 of world’s crude oil reserves are in the Middle East Developed nations consume more energy than developing nations – because they rely more on equipment and technology It takes energy to make energy Net energy = energy returned – energy invested (difference) Energy returned on investment EROI = energy returned / energy invested (ratio) High ratio more energy returned per unit energy that we invest Fossil fuels have high EROI Coal, Natural Gas, and Oil Coal is the world’s most abundant fossil fuel Coal = organic matter (generally woody plant material) that was compressed under very high pressure to form dense, carbon-rich solid material. Coal results when little decomposition occurs (organic material can’t be digested) because the right decomposers aren’t present. 1/5 of world’s commercial energy consumption Coal = rock; whereas its precursor peat = soil Coal is mined from the surface and from below ground We reach underground deposits with subsurface mining – shafts are dug deep into the ground, and networks of tunnels are dug to follow coal seams When coal deposits are at or near the surface, open-pit or strip-mining methods are used. Strip-mining = removing earth in long, horizontal strips to expose the layers or seams of coal Coal varies in its qualities – water content and amount of potential energy it contains Peat = organic material that is broken down anaerobically but remains wet As peat decomposes further, it becomes buried more deeply under sediments, as pressure and heat increase, water is squeezed out. Coal is classified into 4 types: lignite (least compressed), sub-bituminous, bituminous, and anthracite (most compressed = most energy content per unit volume) Coal impurities Sulfur – high sulfur containing coal = when seawater present. China’s coal has high-sulfur content sulphate air pollutants Mercury – bioaccumulates in organism’s tissues, poisoning animals as it moves up food chains Natural gas is the fastest-growing fossil fuel in use today – it’s the cleanest but will run out in 60 years Natural gas = primarily methane and varying amounts of other volatile hydrocarbons Natural gas is formed in two ways: Biogenic gas – created in shallow depths by anaerobic decomposition of organic matter by bacteria Thermogenic gas= results from compression of organic material, accompanied by heating deep underground Natural gas has only recently been widely used It is versatile and clean-burning, emitting half as much CO2 per unit of energy produced as coal and 2/3 as much as oil Converted to liquids (LNG), it can be shipped long distances. Natural gas deposits greatest in Russia and Middle East. Russia, U.S. and Canada are largest producer of natural gas. Natural gas extraction becomes more challenging with time Similar to oil and coal, many of the most accessible natural gas reserves have already been exhausted, causing their production do decline. More sophisticated techniques are now required. Offshore drilling produces much of our gas and oil Oil is the world’s most-used fuel since 1960s Heat and pressure underground form petroleum Petroleum geologist infer the location and size of deposits We have to drill to extract oil primary extraction, and then secondary extraction Petroleum products have many uses once crude oil is extracted; it is put through refining processes. We may have already depleted half our oil reserves To estimate how long this remaining oil will last, analysts calculate reserves-to-production ratio (total remaining reserves / annual rate of production) Hubbert’s peak – 1970 “Unconventional” Fossil Fuels Oil sands, oil shale, and methane hydrates Oil sands / tar sands = deposits of moist sand and clay containing bitumen (thick form of petroleum) Oil shale = sedimentary rock that contains abundant kerogen, which can be processed to produce liquid petroleum Methane hydrate = crystal lattice of water ice molecules occurs in underground locations These 3 alternatives fossil fuels are abundant, but EROI is low (net energy values are low). Severe environmental impacts. Environmental Impacts of Fossil Use Fossil fuel emissions cause pollutions and drive climate change CO2 is a greenhouse gas warms our planet changes in global climate Methane is a greenhouse gas Mercury Sulfur dioxides and nitrogen dioxides contribute to industrial and photochemical smog and to acidic deposition Fossil fuels can pollute water as well as air Some emissions from fossil fuel burning can be “captured” Carbon capture and storage (CCS) is a new technology sequestration = storage of materials in geologic reservoirs on a long timescale Coal mining affects the environment Surface strip-mining – destroys habitat and causes soil erosion Can also cause chemical runoff into waterways through process of acid drainage Oil and gas extraction can alter the environment Not only drilling is done for oil or gas field. But also road networks, housing for workers, transport pipelines, ponds for collecting toxic sludge, etc. Political, Social and Economic Aspects Nations can become dependent on foreign energy Oil supply and prices affect the economies of nations – hurricane Katrina, conflicts with Middle East, OPEC 1973 Residents may or may not benefit – in developing nations, money that is given to govts for access does not trickle down to the locals Energy conservation has followed economic need Energy conservation = practice of reducing energy use to extend the lifetimes of our nonrenewable energy supplies, to be less wasteful, and to reduce our environmental impact Personal choice and increased efficiency are two routes to conservation As individuals, make more conscious choices to reduce our own energy consumption – turning off lights, driving less, efficient engines, hybrids, etc. Improve efficiency of power plants – cogeneration = excess heat producing during the generation of electricity is captured and used to heat workplaces and homes and to produce other kinds of power Both conservation and renewable energy are needed