1. 3.1 TIFFANYS, KARENS AND HENRY

2. Environmental issues  Three general categories: resource use, Population growth, and pollution

3. Resource Use  Natural resource include these two kinds of things:  Natural resource: anything in the environment that is used by people  Renewable resources: resources that are either always available in the nature or can be replace in a reasonably short time.  Example: sunlight, wind, fresh water, trees.

4. Resource use  Unrenewable resources: resource that are not replaced in a reasonable time frame.  Example: coal, oil.

5. Population growth  Improvements in medicine, agriculture, waste disposal  When population grows, the demand for resources also grows.

6. Pollution  The contamination of Earth’s environment  Factors: Chemicals, wastes, noise, heat, and light  Relate to resource use  Harm the natural ecosystem as well as the human health

7. Making Environmental Decision  Making decisions to solve environmental issues  Can be at personal, local, national, or global levels.  Many personal decisions (riding a bike instead of driving your car) combined can be a huge impact on environment.

8. Balancing different needs  Environmental science: the study of natural processes in the environment and how humans can affect them  Environmental decision requires the balance between the needs of the environment and human need.  Decision makers will have to consider the costs and benefits of a proposal.

9. Types of costs and benefits  Often economic benefit  Ecological cost  Jobs created  Sometimes short terms cost can be outweighed by its long-term benefit

10. Weighing costs and benefits  After identifying the costs and benefits of a decision, then you study the pros and cons of a decision.

11. Reference  http://image.baidu.com/search/detail?ct=503316480&z=0&tn=baid uimagedetail&ipn=d&cl=2&cm=1&sc=0&lm=- 1&ie=gbk&pn=0&rn=1&di=32973835180&ln=30&word=%CE%ED%F6% B2&os=1143947977,1806806125&cs=1426993368,1833390857&objurl= http%3A%2F%2Fimg01.hc360.com%2Fcm%2F201503%2F20150305102 0092996.jpg&bdtype=0&simid=3208525574,2945847451&fr=ala&ori_q uery=%E9%9B%BE%E9%9C%BE&ala=0&alatpl=sp&pos=1