1 An Introduction to Environmental ScienceFoundations of Environmental Science

2 OBJECTIVES TO UNDERSTAND:The meaning of the term environment The importance of natural resources That environmental science is interdisciplinary Scientific methods and how science operates Some pressures facing the global environment Sustainability and sustainable development

3 Environment: the total of our surroundingsAll the things around us with which we interact: Living things Animals, plants, forests, fungi, etc. Nonliving things Continents, oceans, clouds, soil, rocks Our built environment Buildings, human-created living centers Social relationships and institutions

4 Humans and the world around usHumans change the environment often in ways not fully understood We depend completely on the environment for survival Increased wealth, health, mobility, leisure time But, natural systems have been degraded i.e., pollution, erosion and species extinction Environmental changes threaten long-term health and survival Environmental science is the study of: How the natural world works How the environment affects humans and vice versa

5 Natural resources: vital to human survivalNatural resources = substances and energy sources needed for survival Renewable resources: Perpetually available: sunlight, wind, wave energy Renew themselves over short periods: timber, water, soil These can be destroyed Nonrenewable resources: can be depleted Oil, coal, minerals

6 Global human population growthMore than 7.4 billion humans Why so many humans? Agricultural revolution stable food supplies Industrial revolution urbanized society powered by fossil fuels sanitation and medicines more food

7 Thomas Malthus and human populationPopulation growth must be restricted, or it will outstrip food production Starvation, war, disease Neo-Malthusians Population growth has disastrous effects Paul and Anne Ehrlich, The Population Bomb (1968)

8 Paul and Anne Ehrlich and the “Population Bomb” (1968)Neo-Malthusians Population growth has disastrous effects A rapidly increasing human population would bring famine & civil strife Population control is the only way to avoid starvation & war Supporters predict global food crisis in the near future

9 Garrett Hardin’s Tragedy of the CommonsResource consumption exerts social & environmental impacts Unregulated exploitation leads to resource depletion Soil, air, water Resource users are tempted to increase use until the resource is gone (individual self-interest will NOT serve the public interest) While the benefits accrue solely to the user, the costs are spread among all others sharing the commons Solutions? Private ownership? Voluntary organization to enforce responsible use? Governmental regulations?

10 The “ecological footprint” (Wackernagel & Rees)The environmental impact of a person or population Amount of biologically productive land + water for raw materials and to dispose/recycle waste Overshoot: humans have surpassed the Earth’s productive capacity We are using more of the planet’s resources than are available on a sustainable basis!

11 Environmental science… can help us avoid mistakes made by past civilizations. The lesson of Easter Island: people annihilated their culture by destroying their environment. Can we act more wisely to conserve our resources?

12 Environmental science: how does the natural world work?Environment  impacts  Humans It has an applied goal: developing solutions to environmental problems An interdisciplinary field Natural sciences: information about the world Environmental Science programs Social sciences: values and human behavior Environmental Studies programs

13 What is an “environmental problem”?The perception of what constitutes a problem varies between individuals and societies Ex.: DDT, a pesticide In developing countries: welcome because it kills malaria-carrying mosquitoes In developed countries: not welcome, due to health risks

14 Environmental science is not environmentalismThe pursuit of knowledge about the natural world Scientists try to remain objective Environmentalism A social movement dedicated to protecting the natural world

15 The nature of science Science:A systematic process for learning about the world and testing our understanding of it A dynamic process of observation, testing, and discovery The accumulated body of knowledge that results from this process Science is essential To sort fact from fiction Develop solutions to the problems we face

16 Applications of sciencePolicy decisions and management practices Technology Energy-efficient methanol-powered fuel cell car from DaimlerChrysler Restoration of forest ecosystems altered by human suppression of fire

17 Scientific method Technique for testing ideas with observationsAssumptions: The universe works according to unchanging natural laws Events arise from causes, and cause other events We use our senses and reason to understand nature’s laws

18 Scientific method A scientist makes an observation and asks questions of some phenomenon The scientist formulates an hypothesis, a statement that attempts to explain the scientific question The hypothesis is used to generate predictions, which are specific statements that can be directly and unequivocally tested The test results either support or reject the hypothesis

19 Experiments test the validity of a hypothesisManipulative experiments yield the strongest evidence But, lots of things can’t be manipulated Natural or correlational tests show real-world complexity Results are not so neat and clean, so answers aren’t simply black and white

20 Ecology Uses both manipulative and natural experimentsECOLOGY – examines the distribution and abundance of organisms, and the interactions among organisms, and the interactions with their environment

21 The scientific process is part of a larger processThe scientific process includes peer review, publication, and debate A consistently supported hypothesis becomes a theory, a well-tested and widely accepted explanation With enough data, a paradigm shift – a change in the dominant view – can occur

22 Population & consumptionHuman population growth exacerbates all environmental problems The growth rate has slowed, but we still add more than 200,000 people to the planet each day Our consumption of resources has risen even faster than our population growth Life has become more pleasant for us so far However, rising consumption amplifies the demands we make on our environment

23 Ecological footprints are not all equalThe ecological footprints of countries vary greatly The U.S. footprint is almost 5 times greater than the world’s average Developing countries have much smaller footprints than developed countries

24 We face challenges in agricultureExpanded food production led to increased population and consumption It’s one of humanity’s greatest achievements, but at an enormous environmental cost Nearly half of the planet’s land surface is used for agriculture Chemical fertilizers Pesticides Erosion & runoff Pollution Changed natural systems

25 We face challenges in pollutionWaste products and artificial chemicals used in farms, industries, and households Each year, millions of people die from pollution

26 We face challenges in climateScientists have firmly concluded that humans are changing the composition of the atmosphere Dependence on fossil fuel major cause The Earth’s surface is warming Melting glaciers Rising sea levels Impacted wildlife and crops Increasingly destructive weather Spread of tropical diseases Since the Industrial Revolution, atmospheric carbon dioxide concentrations have risen by 37%, to the highest level in 650,000 years

27 We face challenges in biodiversityHuman actions have driven many species extinct, and biodiversity is declining dramatically We are at the onset of a mass extinction event Biodiversity loss may be our biggest environmental problem; once a species is extinct, it is gone forever

28 The Millennium Ecosystem AssessmentThe most comprehensive scientific assessment of the condition of the world’s ecological systems Major findings: Humans have drastically altered ecosystems These changes have contributed to human well-being and economic development, but at a cost Environmental degradation could get much worse Degradation can be reversed, but it requires work

29 Our energy choices will affect our futureThe lives we live today are due to fossil fuels Machines Chemicals Transportation Products Fossil fuels are a one-time bonanza; supplies will certainly decline We have used up ½ of the world’s oil supplies; how will we handle this imminent fossil fuel shortage?

30 Are things getting better or worse?Many people think environmental conditions are better Cornucopians: Human ingenuity will solve any problem Some think things are much worse in the world Cassandras: predict doom and disaster How can you decide who is correct? Are the impacts limited to humans, or are other organisms or systems involved? Are the proponents thinking in the long or short term? Are they considering all costs and benefits?

31 Sustainable solutions existWe must develop solutions that protect both our quality of life and the environment Soil conservation, better irrigation, organic agriculture Technology & laws Reduce pollution Biodiversity Protect species Waste disposal Recycling Alternative fuels

32 Sustainability: a goal for the futureHow can humans live within the planet’s means? Humans cannot exist without functioning natural systems Sustainability Leaves future generations with a rich and full Earth Conserves the Earth’s natural resources Provides long term solutions Maintains fully functioning ecological systems Sustainable development: the use of resources to satisfy current needs without compromising future availability of resources

33 Will we develop in a sustainable way?The triple bottom line: sustainable solutions that meet Environmental goals Economic goals Social goals Requires that humans apply knowledge from the sciences to Limit environmental impacts Maintain functioning ecological systems

34 Conclusion Environmental science helps us understand our relationship with the environment and informs our attempts to solve and prevent problems. Identifying a problem is the first step in solving it Solving environmental problems can move us towards health, longevity, peace and prosperity Environmental science can help us find balanced solutions to environmental problems