310 likes | 507 Views
Introducing Environmental Science and Sustainability. 1. Overview of Chapter 1. Human Impacts on The Environment Population, Resources and the Environment Sustainability Environmental Science Addressing Environmental Problems. The Environment (Earth).
E N D
Overview of Chapter 1 • Human Impacts on The Environment • Population, Resources and the Environment • Sustainability • Environmental Science • Addressing Environmental Problems
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
Human Impacts on Environment- Population • Earth’s Human Population is at 6.9 billion • Growing exponentially • Expected to add several billion more people in 21st century
Extreme Poverty • 1 in 4 people in the world live in extreme poverty • Cannot meet basic need for • Food • Safe drinking water • Clothing • Shelter • Health • Sanitation & Education
Extreme Poverty • Extreme poverty was defined in 1996 by Joseph Wresinski • Defined as : the absence of one or more factors enabling individuals and families to assume basic responsibilities and to enjoy fundamental rights. • The World Bank defined the new international poverty line as $1.25 a day for 2005
Less vs. Highly Developed • 81% of the world’s population live in poor countries • Development Ranges of Countries • Less developed (LDC’s – Bangladesh, Ethiopia & Laos) • Moderately developed (MDC’s - Mexico, South Africa & Thailand) • Highly developed (HDC’s – Canada, Japan, USA & most of Europe)
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
Gap Between Rich and Poor • Highly Developed Countries (HDC) • Complex industrialized bases • low population growth • high per capita incomes • Ex: US, Canada, Japan
Population/Resources&Environment • Nonrenewable resources • Present in limited supplies and are depleted by use • Aluminum, tin, copper, fossil fuels • Renewable resources • Replaced by nature fairly rapidly and can be used forever as long as they are not overexploited in the short term • Trees, animals, soils, fresh water
Consumption • Consumption • Human use of materials and energy • People in HDCs are big consumers • Children born in HDC’s cause a greater impact on the environment and on resource depletion then 12 or more born in developing countries. • 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
Ecological Footprint • The average amount of land, water and ocean required to provide that person with all the resources they consume A Hectare = 10,000 square meters (100 m x 100 m)Primarily used in the measurement of land (A football field is 0.54 hectares)
Ecological Footprint • Humans have an ecological overshoot
Environmental Impact Affluence per person I = P A T Environmental effect of technologies Number of people IPAT Model • Measures 3 factors that affect environmental impact (I)
IPAT Model • P = Population • The number of people • A = Affluence (wealth) • represents the average consumption of each person in the population • T = Technology • represents how resource intensive the production of affluence is; how much environmental impact is involved in creating, transporting and disposing of the goods, services and amenities used.
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 • An understanding that earth’s resources are not infinite
Tragedy of the Commons (1968 Paper) • Garrett Hardin (1915–2003) • an American ecologist who warned of the dangers of overpopulation • called attention to • “the damage that innocent actions by individuals can inflict on the environment” • He is also known for Hardin's First Law of Human Ecology: • "You cannot do only one thing", which expresses the interconnectedness of every action
Sustainable Development • Economic development that meets the needs of the present generation without compromising future generations
Environmental Science • An interdisciplinary study of human relationship with other organisms and the earth • Biology • Ecology • Geography • Chemistry • Geology • Physics • Economics • Sociology • Demography • Politics
Earth System and Environmental Science • System • A set of components that interact & function as a whole • Model • Used to describe interactions of environmental systems • Global Earth Systems • Climate, atmosphere, land, coastal zones, ocean • Ecosystem • A natural system consisting of a community of organisms and its physical environment
Earth Systems and Environmental Science • Negative feedback • Change triggers a response that counteracts the changed condition
Positive Feedback • Positive feedback • Change triggers a response that intensifies the changing condition
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
Five Steps to Addressing Environmental Problem • Case Study: Lake Washington • Five steps are idealistic • Scientific Assessment • Risk analysis • Public Education & Involvement • Political Action • Long-term Evaluation
Assessing Environmental ProblemCase 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
Assessing Environmental ProblemCase 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
Assessing Environmental ProblemCase 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)
Assessing Environmental ProblemCase Study: Lake Washington • Results
To discuss: • Come up with 10 reasons why • Children born in HDC’s cause a greater impact on the environment and on resource depletion then 12 or more born in developing countries. • Ted talks – Building a toaster from scratch • http://www.ted.com/talks/thomas_thwaites_how_i_built_a_toaster_from_scratch.html