I.Science and the Environment A.Pollution- the fouling of earth’s land, water, and air in ways that upset health, life, and natural resources 1.Some can come from natural sources but most is caused by humans. 2.Environmental threats: a.ozone depletion – caused by the use of CFC’s that increase UV exposure causing cancer and other health problems b.acid rain – air pollutants mix with rain and make it acidic; can contaminate lakes and forests, erode buildings c.greenhouse effect – burning fossil fuels traps heat and warms the planet; brings climate changes and sea level rise

3.Sources of Pollution a.transportation – fossil fuel exhaust b.manufacturing / industry – releases chemicals into the air and water c.using paper and wood – destroys forests; reduction of trees enhances greenhouse effect d.CFC’s – depletes the ozone layer e.agriculture – depletes nutrition in topsoil; erosion; fertilizer runoff; pesticides f.households – produce sewage and trash; burning waste pollutes air; burying pollutes soil

4.Pollution can be divided into 2 categories: a.point source – is a specific source of pollution that is easily identified b.nonpoint source - may be widespread or come from somewhere unknown B.Human Activities and the Environment 1.Risks that result from human actions: a.greenhouse effect – changes in climate, melting polar ice caps, drought and flooding b.acid rain – destroy forests, poison lakes, kill wildlife, erode statues and buildings c.ozone depletion – higher chances of skin cancer d.air pollution – increases in disease, decrease in health

e.water pollution – threaten species that live in water, less clean water for drinking and farming f.soil degradation / depletion – threat to agriculture, organisms that live in soil g.habitat destruction – threatens species that live there and disrupts the balance of nature C.Ways to Protect the Environment 1.Reduce, Reuse, and Recycle 2.Drive fuel-efficient cars 3.Conserve electricity and water 4.Grow and buy organic food 5.Use public transportation

D.Resources 1. Renewable resources - they can be replaced naturally as we use them a.air (wind energy) b.soil c.water (hydroelectricity) d.sun (solar energy) e.heat from inside the earth (geothermal energy) 2.Nonrenewable resources – energy that is used up faster than natural processes can replace them a.coal b.oil c.natural gas