Lecture 4 - Announcements Tutorials – start next week Jan...

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Unformatted text preview: 1/20/2011 Announcements Tutorials – start next week Jan 25th – Preview of tutorial groups (hopefully!) will be posted this evening, switching within a timeslot permitted until Sun – Tutorial #1 worksheet – Science and the Media, now posted. Must complete and hand in at first tutorial Human Population January 20, 2011 Find a recent article touching on a science issue, answer questions to help determine credibility 1 ENV200Y TUTORIAL ROOM LOCATIONS CODE T0101A T0101B T0201A T0201B T0201C T0301A T0301B T0301C T0401A T0501A T0601A T0601B T0701A T0701B T0701C T0801A T0801B T0801C TIME TUES @ 10 TUES @ 10 TUES @ 12 TUES @ 12 TUES @ 12 TUES @ 1 TUES @ 1 TUES @ 1 WED @ 11 WED @ 1 THURS @ 10 THURS @ 10 THURS @ 12 THURS @ 12 THURS @ 12 THURS @ 1 THURS @ 1 THURS @ 1 Outline LOCATION LM 155 LM 123 BF 315 SS 2128 BF 323 BF 323 SS 2128 LM 123 BF 315 LM 123 RW 229 UC 85 SS 1088 BF 315 RL 14081 BF 315 LM 123 MP 118 Sustainable development – def’n & dilemma Sustainable consumption – Voluntary simplicity Overview of global environmental issues generated by population & consumption – Added complexity of “Tragedy of the Commons” Understanding human population dynamics 3 4 The The dilemma: Sustainable Development 1. Sustainable development advocates global economic growth of 5 to 10x (goal = alleviating poverty). How can that be achieved without exceeding the carrying capacity of ecosystems? 2. Formulations of development policy are to have “broadly-based participation.” How can “broadlywe achieve the radical political/social revisions prerequisite to ecological sustainability by consensus? 5 6 1 1/20/2011 Sustainable Consumption Sustainable Consumption Using goods and services for our basic needs Minimizes use of resources, preserve for future generation Eliminate consumption overpopulation Requires eradication of poverty Poor will need to increase consumption: why? Will require major lifestyle changes Voluntary simplicity Source: The Story of Stuff 7 Voluntary Simplicity 8 Steady State Economy Recognition that economic growth has limits aims for stable or mildly fluctuating aims levels in population and consumption of energy and materials. Birth rates equal death rates, and saving/investment equals depreciation. How should you live? Material wealth not required for happiness Values and character important How can you make changes? 9 Does This Sound Sustainable? 10 Does This Sound Sustainable? Nonrenewable resources being rapidly depleted Many renewable resources being used in a nonrenewable nonrenewable way Environment is being polluted Human population is increasing 11 12 2 1/20/2011 Tragedy of the Commons (p.34) Human Population Dynamics First defined by Garrett Hardin in 1968 Commons: available to everyone but no single individual has responsibility Tragedy: short term individual welfare trumps long term environmental sustainability 13 14 How Populations Change Population Ecology Branch of biology Study of populations Individuals of a particular species How they respond to the environment Increase or decrease in number over time 15 16 Maximum Population Growth How Populations Change Global scale: dependent on two things Birth rate (b) Death rate (d) Growth rate (r) r=b–d Local populations Dispersal Immigration (i) Emigration (e) Growth Rate = (birth rate + immigration rate) – (death rate + emigration rate) 17 Biotic potential Maximum rate at which population can increase Determined by life history characteristics Large organisms smallest biotic potentials Microorganisms largest biotic potentials 18 3 1/20/2011 Environmental Resistance Exponential Population Growth Optimal conditions Constant reproductive rate J-shaped curve Unfavorable environmental conditions Prevent reproduction at biotic potential Examples? Environment controls population size: how? 19 20 Carrying Capacity Carrying Capacity Largest population that can be sustained indefinitely Changes in response to environment J-shaped curve S-shaped curve Populations are always changing Slightly above or below carrying capacity Too high crash 21 22 The Human Population Thomas Malthus Currently ≈ 6.6 billion people (2006) 7 billion by 2013 Why the increase? 23 British economist (1766–1834) (1766– Hypothesized that human population would be kept in check: how? Thinking shaped by rapid urbanization & industrialization Was he correct? 24 4 1/20/2011 Projecting Future Population Earth’s Carrying Capacity World growth rate has declined slightly Zero population growth Birth rate = death rate End of 21st century U.N. predicts 7.7–10.6 7.7– billion by 2050 4 billion – 16 billion people Why such a large range? What could happen to the environment? Have we already exceeded our carrying capacity? 25 26 Demographics Demographics Demographics Study of populations in various countries Highly developed countries Low birth rates Low infant mortality Longer life expectancies High GNI PPP, e.g. Can $36K, global $7K e.g. 27 Less developed countries High birth rates High infant Hi mortality mortality Shortest life expectancies Low GNI PPP 28 Alternatives to GNI PPP (Gross National Income in Purchasing Power Parity) The Human Development Index (http://hdr.undp.org/en/statistics/hdi/) Genuine Progress Indicator Progress Indicator (http://www.pembina.org/economics/gpi) 29 5 ...
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This note was uploaded on 08/10/2011 for the course ENV 200 taught by Professor Karening during the Spring '11 term at University of Toronto.

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