Chapter 1 Environmental Science and Sustainability

Transcription

1 Chapter 1 Environmental Science and Sustainability

2 Overview Human Impacts on the Environment Population, Resources and the Environment Environmental Sustainability Environmental Science Addressing Environmental Problems

3 Ecology Scientific study of interactions among organisms and their environment Environmental science is interdisciplinary Biology Physics Ecology Economics Geography Sociology Chemistry Politics Geology

4 The Environment (Earth) Earth is well-suited for life Water covers ¾ of planet Habitable temperature, moderate sunlight Atmosphere provides oxygen and carbon dioxide Soil provides essential minerals for plants Life has existed on earth for ~3.8 billion years Humans are altering the planet s natural systems

5 Human Impact on the Environment Satellite view of North America at night

6 Human Impacts on Environment Population Human population is over 7 billion people Growing exponentially

7 Human Impacts on Environment Population

8 Population 1 in 4 people live in extreme poverty Cannot meet basic needs for food, water, clothing, shelter, health Difficult to meet population needs without exploiting earth s resources

9 Gap Between Rich and Poor Highly Developed Countries (HDC) Complex industrialized bases, low population growth, high per capita incomes Ex: US, Canada, Japan Less Developed Countries (LDC) Low level of industrialization, very high fertility rate, high infant mortality rate, low per capita income Ex: Bangladesh, Mali, Ethiopia

10 Gap Between Rich and Poor Islamabad, Pakistan Mumbai, India Philippines Pennsylvania

11 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

12 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 Amount Each Person is Allotted (divide Productive Land and Water by Human Population (~7.1 billion) Current Global Ecological Footprint of each person 11.4 billion hectares 1.6 hectares 2.7 hectares!

13 Ecological Footprint Comparison How is this possible?

14 Ecological Footprint Comparison Most of the human population has a relatively small ecological footprint (i.e. they are economically poor) Technologies allow us to borrow resources for short term gains (this is not sustainable)

15 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

16 IPAT Model Effects of technology vs. Panning for gold Hydraulic mining for gold

17 IPAT Model Effects of technology vs. Plow and ox Diesel tractor

18 IPAT Model Effects of technology vs. Native American spear fishing Commercial trawler

19 IPAT Model Effects of technology vs. Logging with axes Industrial logging

20 Types of Natural Resources

21 Tragedy of the Commons Garrett Hardin ( ) The commons (pasture land) in medieval Europe illustrates the demand on public resources Solving environmental problems is the result of balancing: Short term welfare Long term environmental stability and societal welfare

22 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

23 Sustainable Development Economic development that meets the needs of the present generation without compromising future generations Dubai s Sustainable City to be completed in 2016

24 Environmental Sustainability

25 Science From the Latin scientia meaning knowledge An effort to understand how the universe works through the Scientific Method Observable evidence Thought Experimentation Builds on previous knowledge Is the earth round?

26 Scientific Method

27 Controls and Variables in Experiments 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

28 Addressing Environmental Problems Textbook case study: Lake Washington

29 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

30 Assessing Environmental Problem Case Study: Lake Washington Cyanobacteria (blue-green algae) bloom

31 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

32 Assessing Environmental Problem Case Study: Lake Washington Public Education and 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)

33 Assessing Environmental Problem Case Study: Lake Washington Monitoring Results

34 Assessing Environmental Problem Case Study: Lake Washington Lake Washington today