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Our island: Earth • Earth may seem enormous But it and its systems are finite and limited We can change the Earth and damage its systems • Environment: all the living and nonliving things around us Animals, plants, forests, farms, etc. Continents, oceans, clouds, ice caps Structures, urban centers, living spaces Social relationships and institutions Humans are part of nature • Humans depend on a healthy, functioning planet • The fundamental insight of environmental science: We are part of the natural world, but we can also change it Our interactions with its other parts matter a great deal • We depend completely on the environment for survival Increased health, longer lives, wealth, mobility, leisure But natural systems have been degraded by pollution, soil erosion, species extinction, etc. Environmental changes threaten longterm health and survival Environmental science • Environmental science is the study of: How the natural world works How the environment affects humans and vice versa • We need to understand our interactions with the environment to creatively solve environmental problems Global conditions are rapidly changing We are also rapidly gaining knowledge The opportunity to solve problems is still available We rely on natural resources • Natural resources = substances and energy sources needed for survival • Renewable natural resources: can be replenished in a reasonable timeframe Perpetually renewed: sunlight, wind, wave energy Renew themselves over short periods: timber, water, soil These can be destroyed • Nonrenewable natural resources: unavailable after depletion Oil, coal, minerals We rely on ecosystem services • Natural resources are “goods” produced by nature Earth’s natural resources provide “services” to us • Ecosystem services: arise from the normal functioning of natural services Purify air and water, cycle nutrients, regulate climate Pollinate plants, receive and recycle wastes • We degrade ecosystem services By depleting resources, destroying habitat, generating pollution Increased human affluence has intensified degradation Human population growth amplifies impacts • There are over 7.3 billion humans • Agricultural revolution Crops, livestock Stable food supplies • Industrial revolution Urbanized society powered by fossil fuels (oil, gas, coal) Sanitation and medicines Pesticides and fertilizers http://www.census.gov/popclock/ What is the Tragedy of the Commons? • Using our Fishing Activity, think about the best mathematical strategy for the harvest of natural resources. • Is there a solution to the Tragedy of the Commons? http://www.youtube.com/watch?v=MLirNeuA8I `Resource consumption exerts pressures • Exploitation and consumption of resources is also a problem • Garret Hardin’s tragedy of the commons: unregulated exploitation of public resources leads to depletion and damage Soil, air, water • Resource users are motivated by self interest They increase use until the resource is gone • Solutions to the tragedy of the commons? Private ownership? Voluntary organization to enforce responsible use? Governmental regulations? Our “ecological footprint” • Affluence increases consumption • Ecological footprint: the environmental impact of a person or population The area of biologically productive land + water To supply raw resources and dispose/recycle waste • People in rich nations have much larger ecological footprints If everyone consumed the amount of resources the U.S. does, we would need 4.5 Earths Overshoot Overshoot: humans have surpassed the Earth’s capacity to support us We are using renewable resources 30% faster than they are being replenished Environmental science • How will resource consumption and population growth impact today’s global society? • Civilizations have fallen after degrading the environment Easter Island, Greek and Roman empires Once lush regions (i.e. Iraq) are now barren deserts • Civilizations succeed or fail according to how they interact with the environment Along with how they respond to problems • Environmental science can help build a better world The nature of environmental science Environment ç impacts è Humans • Its applied goal: solving environmental problems Solutions are applications of science • An interdisciplinary field Natural sciences: examines the natural world Environmental science programs Social sciences: examines values and human behavior Environmental studies programs What is an “environmental problem”? • Whether an environmental condition is seen as a problem Depends on the individual and situation • Ex.: the pesticide DDT In malariainfested Africa: welcome because it kills malariacarrying mosquitoes In America: not welcome, due to health risks People also differ in their awareness of problems, depending on who they are, where they live, what they do Environmental science is not environmentalism • Environmental science Pursues knowledge about the environment and our interactions with it Scientists try to remain objective and free from bias • Environmentalism A social movement Tries to protect the natural world from humancaused changes Science asks and answers questions • It is an incremental approach to the truth • Scientists do not simply accept conventional wisdom They judge ideas by the strength of their evidence • Observational (descriptive) science: information is gathered about organisms, systems, processes, etc. Cannot be manipulated by experiments Phenomena are observed and measured Used in astronomy, paleontology, taxonomy, genomics • Hypothesisdriven science: targeted research Experiments test hypotheses using the scientific method The scientific process is part of a larger process • It guards against faulty research Includes peer review, publication, competition for funding Sustainability and the future of our world • Sustainability: we must live within our planet’s means So the Earth and its resources can sustain us and all life for the future • Sustainability involves conserving resources Developing longterm solutions Keeping fully functioning ecosystems • Natural capital: Earth’s total wealth of resources We are withdrawing it faster than it’s being replenished We must live off Earth’s natural interest (renewable resources), not its natural capital Population & consumption • Population growth amplifies all human impacts The growth rate has slowed, but we still add more than 200,000 people to the planet each day • Resource consumption has risen faster than population Life has become more pleasant Rising consumption also amplifies our demands on the environment • The 20 wealthiest nations have 55 times the income of the 20 poorest nations Three times the gap that existed 40 years ago Ecological footprints are not all equal • Not everyone benefits equally from rising affluence • The ecological footprints of countries vary greatly The U.S. footprint is much greater than the world’s average • In the U.S. the richest 1% have 25% of all income We face challenges in agriculture • Technology expanded food production Leading to increased population and consumption • It’s one of humanity’s greatest achievements, but it comes at an enormous environmental cost Nearly half of the land surface is used for agriculture Chemical fertilizers and pesticides poison and change natural systems Erosion, climate change and poor management destroy millions of acres each year We face challenges in pollution • Waste products and artificial chemicals Are used in farms, industries, and households Contaminate land, water and air Kill millions of people • Humans are affecting the Earth’s climate Melting glaciers Rising sea levels Impacted wildlife, forests, health and crops Changed rainfall and increased storms Since the Industrial Revolution, atmospheric carbon dioxide concentrations have risen by 39%, to the highest level in 800,000 years We face challenges in biodiversity • Biodiversity: the cumulative number and diversity of living things • Human actions have driven many species extinct Biodiversity is declining dramatically We are setting in motion a mass extinction event Biodiversity loss may be our biggest problem; once a species is extinct, it is gone forever Our energy choices will affect our future • The lives we live today are due to fossil fuels Machines Chemicals Transportation Products • Fossil fuels are a onetime 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? Sustainable solutions abound • • • • • • Renewable energy and efficiency Organic agriculture Legislation and technology to reduce pollution Protect species and their habitat Recycling, decreasing waste Decrease greenhouse gas emissions We must develop solutions that protect both our quality of life and the environment 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 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? Sustainable development • The poor suffer the most from environmental degradation • Development: purposeful changes to improve the quality of life • Sustainable development: resources satisfy current needs Without compromising future availability of resources It is not ever increasing economic gain It values and prioritizes environmental protection Humanmade capital cannot substitute for natural capital Will we develop in a sustainable way? • The triple bottom line: sustainable solutions that meet Environmental protection Economic goals Social equity • Humans must apply knowledge from the sciences to Limit environmental impacts Maintain functioning environmental systems We must make an ethical commitment to current and future generations
