1 Introducing Environmental Science and Sustainability Question of the day: Define environmental sustainability. List three things you do in your life that might be considered a sustainable practice. © 2012 John Wiley & Sons, Inc. All rights reserved. Overview of Chapter 1 Human Impacts on The Environment Population, Resources and the Environment Sustainability Environmental Science Addressing Environmental Problems © 2012 John Wiley & Sons, Inc. All rights reserved. The Environment (Earth) Life has existed on earth for 3.8 billion yrs Earth well suited for life Water over ¾ of planet Habitable temperature, moderate sunlight Atmosphere provides oxygen and carbon dioxide Soil with essential minerals for plants © 2012 John Wiley & Sons, Inc. All rights reserved. Human Impacts on EnvironmentPopulation Earth’s Human Population is at 6.9 billion Growing exponentially Expected to add several billion more people in 21st century © 2012 John Wiley & Sons, Inc. All rights reserved. World Population Clock http://www.census.gov/main/www/popclock.ht ml © 2012 John Wiley & Sons, Inc. All rights reserved. Population 1 in 4 people live in extreme poverty Cannot meet basic need for food, clothing, shelter, health Difficult to meet population needs without exploiting earth’s resources © 2012 John Wiley & Sons, Inc. All rights reserved. Gap Between Rich and Poor Highly Developed Countries (HDC) Complex industrialized bases, low population growth, high per capita incomes Ex: US, Canada, Japan © 2012 John Wiley & Sons, Inc. All rights reserved. Gap Between Rich and Poor Less Developed Countries (LDC) Low level of industrialization, very high fertility rate, high infant mortality rate, low per capita income Ex: Bangladesh, Mali, Ethiopia © 2012 John Wiley & Sons, Inc. All rights reserved. Types of Natural Resources © 2012 John Wiley & Sons, Inc. All rights reserved. Overpopulation People overpopulation Too many people in a given geographic area Problem in many developing nations Consumption overpopulation Each individual in a population consumes too large a share of the resources Problem in many highly developed nations, US in particular © 2012 John Wiley & Sons, Inc. All rights reserved. Consumption Consumption Human use of materials and energy People in HDCs are big consumers Unsustainable Consumption Occurs when the level of demand on a country’s resources damages or depletes the resource enough to reduce the quality of life for future generations Caused by overpopulation and/or overconsumption © 2012 John Wiley & Sons, Inc. All rights reserved. Ecological Footprint The average amount of land, water and ocean required to provide that person with all the resources they consume Earth’s Productive Land and Water 11.4 billion hectares 1.8 hectares Amount Each Person is Allotted (divide Productive Land & Water by Human Pop.) Current Global Ecological Footprint of each person 2.7 hectares © 2012 John Wiley & Sons, Inc. All rights reserved. Ecological Footprint Humans have an ecological overshoot © 2012 John Wiley & Sons, Inc. All rights reserved. Ecological Footprint Comparison © 2012 John Wiley & Sons, Inc. All rights reserved. IPAT Model Measures 3 factors that affect environmental impact (I) Environmental Impact Affluence per person I=P A T Number of people Environmental effect of technologies © 2012 John Wiley & Sons, Inc. All rights reserved. Questions of the day: What was your ecological footprint? What are commons? Why do you think it was high or low? What point is Hardin trying to get across with his piece? What factors may have significantly affected your number? What topics/concepts is this related to in ES? © 2012 John Wiley & Sons, Inc. All rights reserved. Environmental Sustainability © 2012 John Wiley & Sons, Inc. All rights reserved. Environmental Sustainability The ability to meet current human need for natural resources without compromising the needs of future generations Requires understanding: The effects of our actions on the earth That earth’s resources are not infinite © 2012 John Wiley & Sons, Inc. All rights reserved. Tragedy of the Commons Garrett Hardin (1915–2003) Solving Environmental Problems is result of struggle between: Short term welfare Long term environmental stability and societal welfare Common pool resources Garrett used Common Pastureland in medieval Europe to illustrate the struggle © 2012 John Wiley & Sons, Inc. All rights reserved. Sustainable DevelopmentSystems Concept Economic development that meets the needs of the present generation without compromising future generations © 2012 John Wiley & Sons, Inc. All rights reserved. Environmental Science An interdisciplinary study of human relationship with other organisms and the earth Biology Physics Ecology Economics Geography Sociology Chemistry Demography Geology Politics © 2012 John Wiley & Sons, Inc. All rights reserved. Earth System and Environmental Science System A set of components that interact and function as a whole Global Earth Systems Climate, atmosphere, land, coastal zones, ocean Ecosystem A natural system consisting of a community of organisms and its physical environment © 2012 John Wiley & Sons, Inc. All rights reserved. Earth Systems and Environmental Science Negative feedback Change triggers a response that counteracts the changed condition © 2012 John Wiley & Sons, Inc. All rights reserved. Feedback Positive feedback Change triggers a response that intensifies the changing condition © 2012 John Wiley & Sons, Inc. All rights reserved. Scientific Method © 2012 John Wiley & Sons, Inc. All rights reserved. Controls and Variables in Experiment Variable A factor that influences a process The variable may be altered in an experiment to see its effect on the outcome Control The variable is not altered Allows for comparison between the altered variable test and the unaltered variable test © 2012 John Wiley & Sons, Inc. All rights reserved. Five Steps to Addressing An Environmental Problem Five steps are idealistic Case Study: Lake Washington © 2012 John Wiley & Sons, Inc. All rights reserved. Assessing Environmental Problem Case Study: Lake Washington Large, freshwater pond Suburban sprawl in 1940’s 10 new sewage treatment plants dumped effluent into lake Effect = excessive cyanobacteria growth that killed off fish and aquatic life © 2012 John Wiley & Sons, Inc. All rights reserved. Assessing Environmental Problem Case Study: Lake Washington Scientific Assessment Aquatic wildlife assessment done in 1933 was compared to the 1950 assessment Hypothesized treated sewage was introducing high nutrients causing growth of cyanobacteria Risk Analysis After analyzing many choices, chose new location (freshwater) and greater treatment for sewage to decrease nutrients in effluent © 2012 John Wiley & Sons, Inc. All rights reserved. Assessing Environmental Problem Case Study: Lake Washington Public Education/Involvement Educated public on why changes were necessary Political Action Difficult to organize sewage disposal in so many municipalities Changes were not made until 1963! Evaluation Cyanobacteria slowly decreased until 1975 (gone) © 2012 John Wiley & Sons, Inc. All rights reserved. Assessing Environmental Problem Case Study: Lake Washington Results © 2012 John Wiley & Sons, Inc. All rights reserved.