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Environmental Science The study of the impact of humans on the environment. •Major focus is to understand and solve environmental problems. *We have caused huge problems. They are expensive to fix • Environment--- refers to everything that surrounds us, the natural world as well as things produced by humans. • It is a complex web of relationships Devil’s Tower Historical view of environment • 1. Hunter-Gatherers- obtain food by hunting animals and gathering plants • Small groups that migrated • Minimal damage to env. by humans 2. Agricultural Revolution-grow your own food- use plants for other purpose too • Allows larger populations to survive Agriculture • Farmers then chose seeds from plants with the best traits-larger fruit=more food • Also changed forested lands into farm lands (sometimes over-worked soil), increased damage to env. History continued • 3. Industrial Revolution-use of machines made it much more efficient for agriculture practices, industry and transportation • Goods less expensive • More food available • Urban areas grow-fewer need to farm • More use of fossil fuels and many new environmental problems= much env. damage And the population grows • During the 20th century the population grows from around 1.5 to 6 Billion- on October 12, 1999 • click for population clock 3 main environmental problems • Resource Depletion • Pollution • Loss of Biodiversity 1.Resource depletion -using a large part of what we have • Natural resource- any natural material used by humans. Ex. Sunlight, fresh water, plants, fossil fuels & forests. Milham Reservoir • Nonrenewable resource- cannot be replaced because it forms at a slow rate. Ex. Copper & oil Morenci Open Pit Mine, Arizona • Renewable resources- are replaced relatively quickly. Ex. Sunlight, trees, fish. (We must learn to use these at a rate that allows them to renew themselves, trees take years to grow.) 2. Pollution-undesired change in air, water or soil that adversely affects health and survival Ex. Pesticides, oxides (acid rain), human waste, computers. 3. Loss of biodiversity= variety of organisms . Extinction- last member of a species has died out. • Ex. Passenger pigeon. • Most extinctions from habitat destruction Why care about extinction? • Dependence on organisms for food and oxygen • Organism are interconnected (Kill one thing--- a whole ecosystem may become off balance; other species die, or an unwanted species comes in and takes over.) This shows organisms rely first on the sun and plants and then the grasshopper. Shows complexity of food webs. 1-2 Environment And Society • Tragedy of commons (ex. Page 16) • Short term individual interests VS long term welfare of society • If no one takes responsibility then resources can be overused and depleted Economics-influence how we use the env. • Supply and Demand • The greater a demand for a limited supply, the more it’s worth • Cost VS Benefit- one can pay a higher price for a product that meets environmental regulations or pay a lower price and not have that safeguard. • Risk- always a risk to the environment • Developed countries---industrialized, have a high income and produce the most pollution. (U.S.)-slower population growth • Also use the most resources (75%) even though only 20% of world pop. • More waste and pollution per person • Developing countries have little industrialization, little income, higher population growth. (India) • Food production, job creation, education cannot keep up. Ecological footprint- term used for acres needed to support lifestyle • Includes food, housing etc. • • • • U.S. 30 acres Britain 16 Mexico 7 India 3 • ecological footprint link • Many environmental problems can be linked to increasing human population. WHY? • Sustainable world- a world in which human populations can exist indefinitely with a high standard of living and health, while preserving habitats for the rest of the world. • We need to learn to live with the other organisms on our planet, not destroy them. • Problems are global problems. We are interconnected in some way. Our winds and rain blow around the world and carry pollution. Decision Making Table Problem Values Positive Short Term Consequences Negative Short Term Consequences Positive Long term Consequences Negative Long Term Consequences Value-------definition page 47 • • • • • • • • • Aesthetic Economic Environmental Educational Ethic/moral Health Recreational Scientific Social/cultural • • • • • • • • • Beauty Gain/loss jobs or $$$ Protect nat. resources Gain knowledge Is it right or wrong? Maintain human health Leisure activities Understand natural world Keep community, values traditions A hypothetical situation • In the town of Pleasanton, in Valley County, biologists from the local college have been studying the golden-cheeked warbler. The warblers have already disappeared from most areas around the state, and the warbler population is declining in Valley County. The biologists warn county officials that if the officials do not take action, the state fish and wildlife service may list the bird as an endangered species. • Pleasanton is growing rapidly and much of the new development is occurring outside the city limits. This development is destroying the warbler habitat. Valley County already has strict environmental controls on building, but these controls do not prevent the clearing of land where the birds are known to breed. • Continued -- Several groups join together to propose that the county buy several hundred acres of land where the birds are known to breed and save that land as a nature preserve. They also propose limiting development on land surrounding the preserve. The group obtains enough signatures on a petition to put the issue to a vote, and the public begins to discuss the proposal. • Some people who own property within the proposed preserve oppose the plan. These property owners have an economic interest in this discussion. They believe they will lose money if they are forced to sell their land to the county instead of developing it. • They fear that without the preserve the warbler may be placed on the state’s endangered species list. If the bird is listed as endangered, the state will impose a plan to protect the bird that will require even stricter limits on land development. People who have land near the proposed preserve think their land will become more valuable. Many residents of Pleasanton look forward to hiking and camping in the proposed preserve. Other residents do not like the idea of more government regulations on how private properties can be used. Does a gas spill have negative affects? • Gas spill in Marlborough