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This lecture will help you understand: • The meaning of the term environment • The field and interdisciplinary nature of environmental science • The importance of natural resources and ecosystem services • The scientific method and the process of science • Some pressures on the global environment • Concepts of sustainability and sustainable development © 2011 Pearson Education, Inc. 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 non-living things around us - Animals, plants, forests, farms, etc. – Continents, oceans, clouds, ice caps – Structures, urban centers, living spaces – Social relationships and institutions © 2011 Pearson Education, Inc. 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 long-term health and survival © 2011 Pearson Education, Inc. 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 © 2011 Pearson Education, Inc. We rely on natural resources • Natural resources = substances and energy sources needed for survival • Renewable natural resources: can be replenished - 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 © 2011 Pearson Education, Inc. 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 © 2011 Pearson Education, Inc. Human population growth amplifies impacts • There are over 7 billion humans http://www.census.gov/main/ww w/popclock.html • Agricultural revolution - Crops, livestock - Stable food supplies • Industrial revolution - Urbanized society powered by fossil fuels (oil, gas, coal) - Sanitation and medicines - Pesticides and fertilizers © 2011 Pearson Education, Inc. 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? © 2011 Pearson Education, Inc. 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! © 2011 Pearson Education, Inc. Overshoot Overshoot: humans have surpassed the Earth’s capacity to support us We are using renewable resources 30% faster than they are being replenished © 2011 Pearson Education, Inc. 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 © 2011 Pearson Education, Inc. The nature of environmental science Environment impacts 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 © 2011 Pearson Education, Inc. 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 malaria-infested Africa: welcome because it kills malaria-carrying 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 © 2011 Pearson Education, Inc. 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 human-caused changes © 2011 Pearson Education, Inc. Theories and paradigm shifts • Theory: a well-tested and widely accepted explanation – Consolidates widely-supported, related hypotheses • Paradigm shift – a dramatic upheaval in thought – It changes the dominant viewpoint • Wicked problems: are complex, with no simple solution – i.e. environmental problems © 2011 Pearson Education, Inc. 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 long-term solutions - Keeping fully functioning ecosystems • Natural capital: Earth’s total wealth of resources - We are withdrawing it faster that it’s being replenished - We must live off Earth’s natural interest (replenishable resources), not its natural capital © 2011 Pearson Education, Inc. 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 © 2011 Pearson Education, Inc. 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 © 2011 Pearson Education, Inc. 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 © 2011 Pearson Education, Inc. Humans have changed the Earth’s landscape Agriculture, urban sprawl, and other land uses have substantially affected most of the landscape of all nations © 2011 Pearson Education, Inc. 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 © 2011 Pearson Education, Inc. 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 © 2011 Pearson Education, Inc. The Millennium Ecosystem Assessment • The most comprehensive scientific assessment of the condition of the world’s ecological systems • In 2005, 2000 of the world’s leading scientists from 100 nations reported : – Humans have drastically altered ecosystems – These changes have contributed to human wellbeing and economic development, but at a cost – Environmental degradation could get much worse – Degradation can be reversed, but it requires work © 2011 Pearson Education, Inc. 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 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? © 2011 Pearson Education, Inc. Sustainable solutions abound We must develop solutions that protect both our quality of life and the environment • • • • • • Renewable energy and efficiency Organic agriculture Legislation and technology to reduce pollution Protect species and their habitat Recycling, decreasing waste Decrease greenhouse gas emissions © 2011 Pearson Education, Inc. 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? © 2011 Pearson Education, Inc. Sustainable development • Involves environmental protection, economic well-being and social equity • It does not threaten economic and social needs - Humans cannot exist without an intact, functioning ecosystem • Sustainable development: the use of resources to satisfy current needs - Without compromising future availability of resources © 2011 Pearson Education, Inc. 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 - Human-made capital cannot substitute for natural capital © 2011 Pearson Education, Inc. 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 © 2011 Pearson Education, Inc. Conclusion • Environmental science helps us understand our relationship with the environment - It 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 challenges © 2011 Pearson Education, Inc.