生物演化過程中自然選擇的上一步是
ⓐ氣候改變 ⓑ棲地改變 ⓒ基因改變 ⓓ競爭
ANS : ⓒ
2009年6月13日 星期六
2009年4月2日 星期四
地理作業一
1-1 What Is an Environmentally Sustainable Society?
one that meets the current and future basic resource needs of its people in a just and equitable manner without compromising the ability of future generations to meet their basic needs.
Imagine you win $1 million in a lottery. If you invest this money and earn 10% interest per year, you will have a sustainable income of $100,000 a year that you can live off of indefinitely without depleting your capital. However, if you spend $200,000 per year while allowing interest to accumulate on what is left after each withdrawal, your capital of $1 million will be gone early in the seventh year. Even if you spend only $110,000 per year and allow the interest to accumulate,you will be bankrupt early in the eighteenth year.
The lesson here is an old one: Protect your capital and live off the income it provides. Deplete or waste your capital, and you will move from a sustainable to an unsustainable lifestyle.
1-2 How Can Environmentally Sustainable Societies Grow Economically?
Some economists call for continuing conventional economic growth, which has helped increase food supplies,allowed people to live longer, and stimulated mass production of an array of useful goods and services for many people. They also see such growth as a cure for poverty as some of the resulting increase in wealth trickles down to countries near the bottom of the economic ladder.
Other environmental and ecological economists,call for us to put much greater emphasis on environmentally sustainable economic development. This involves using political and economic systems to discourage environmentally harmful and unsustainable forms of economic growth that degrade natural capital, and to encourage environmentally beneficial and sustainable forms of economic development that help sustain natural capital.
1-3 How Are Our Ecological Footprints Affecting the Earth?
The per capita ecological footprint is an estimateof how much of the earth’s renewable resources an individual consumes. After the oil-rich United Arab Emirates, the United States has the world’s second largest per capita ecological footprint. In 2003 (the latest data available), its per capita ecological footprint was about 4.5 times the average global footprint per person, 6 times larger than China’s per capita footprint, and 12 times the average per capita footprint in the world’s low-income countries.
According toWilliam Rees and MathisWackernagel,the developers of the ecological footprint concept, it would take the land area of about five more planet earths
for the rest of the world to reach current U.S. levels of consumption with existing technology. Put another way, if everyone consumed as much as the average American does today, the earth’s natural capital could support only about 1.3 billion people—not today’s 6.7 billion. In other words, we are living unsustainably by depleting and degrading some of the earth’s irreplaceable natural capital and the natural renewable income it provides as our ecological footprints grow and spread across the earth’s surface (Concept 1-3). For more on this subject see the Guest Essay by Michael Cain at ThomsonNOW?. See the Case Study that follows about the growing ecological footprint of China.
1-4 What Is Pollution and What Can We Do about It?
Pollution is any chemical or physical change in the environment that is harmful to humans or other living organisms. Pollutants can enter the environment naturally,
such as from volcanic eruptions, or through human activities, such as burning coal and gasoline.
The answers to these questions involve two different ways of dealing with pollution. One is pollution prevention, or input pollution control, which reduces or eliminates the production of pollutants. The other is pollution cleanup, or output pollution
control, which involves cleaning up or diluting pollutants
Environmental scientists have identified three problems with relying primarily on pollution cleanup. First, it is only a temporary bandage as long as population and consumption levels grow without corresponding improvements in pollution control technology. For example, adding catalytic converters to car exhaust systems has reduced some forms of air pollution. At the same time, increases in the number of cars and the total distance each travels have reduced the effectiveness of this cleanup approach.
Second, cleanup often removes a pollutant from one part of the environment only to cause pollution in another. For example, we can collect garbage, but the
garbage is then burned (perhaps causing air pollution and leaving toxic ash that must be put somewhere), dumped on the land (perhaps causing water pollution through runoff or seepage into groundwater), or buried (perhaps causing soil and groundwater pollution).
1-5 Why Do We Have Environmental Problems?
According to a number of environmental and social scientists, the major causes of these and other environmental problems are population growth, wasteful and unsustainable resource use, poverty, failure to include in market prices the environmental costs of producing and using goods and services, and too little knowledge of how nature works.
The harmful environmental effects of poverty are serious but those of affluence are much worse (Figure 1-8, top). The lifestyles of many affluent consumers in developed
countries and in rapidly developing countries such as India and China (Case Study, p. 13) are built upon high levels of consumption and unnecessary waste of resources. Such affluence is based mostly on the assumption—fueled by mass advertising—that buying more things will bring fulfillment and happiness.
This type of affluence has an enormous harmful environmental impact. It takes about 27 tractor-trailer loads of resources per year to support one American, or 7.9 billion truckloads per year to support the entire U.S. population. Stretched end-to-end, this number of trucks would reach beyond the sun!
1-6 What Are Four Scientific Principles of Sustainability?
‧ Reliance on Solar Energy: the sun warms the planet and supports photosynthesis used by plants to provide food for themselves and for us and other
animals.
‧ Biodiversity (short for biological diversity): the astounding variety of life forms, the genes they contain, the ecosystems in which they exist, and the natural services they provide have yielded countless ways for life to adapt to changing environmental conditions throughout the earth’s history.
‧ Population Control: competition for limited resources among different life forms places a limit on how much their populations can grow.
‧ Nutrient Cycling: natural processes recycle chemicals that plants and animals need to stay alive and reproduce.
one that meets the current and future basic resource needs of its people in a just and equitable manner without compromising the ability of future generations to meet their basic needs.
Imagine you win $1 million in a lottery. If you invest this money and earn 10% interest per year, you will have a sustainable income of $100,000 a year that you can live off of indefinitely without depleting your capital. However, if you spend $200,000 per year while allowing interest to accumulate on what is left after each withdrawal, your capital of $1 million will be gone early in the seventh year. Even if you spend only $110,000 per year and allow the interest to accumulate,you will be bankrupt early in the eighteenth year.
The lesson here is an old one: Protect your capital and live off the income it provides. Deplete or waste your capital, and you will move from a sustainable to an unsustainable lifestyle.
1-2 How Can Environmentally Sustainable Societies Grow Economically?
Some economists call for continuing conventional economic growth, which has helped increase food supplies,allowed people to live longer, and stimulated mass production of an array of useful goods and services for many people. They also see such growth as a cure for poverty as some of the resulting increase in wealth trickles down to countries near the bottom of the economic ladder.
Other environmental and ecological economists,call for us to put much greater emphasis on environmentally sustainable economic development. This involves using political and economic systems to discourage environmentally harmful and unsustainable forms of economic growth that degrade natural capital, and to encourage environmentally beneficial and sustainable forms of economic development that help sustain natural capital.
1-3 How Are Our Ecological Footprints Affecting the Earth?
The per capita ecological footprint is an estimateof how much of the earth’s renewable resources an individual consumes. After the oil-rich United Arab Emirates, the United States has the world’s second largest per capita ecological footprint. In 2003 (the latest data available), its per capita ecological footprint was about 4.5 times the average global footprint per person, 6 times larger than China’s per capita footprint, and 12 times the average per capita footprint in the world’s low-income countries.
According toWilliam Rees and MathisWackernagel,the developers of the ecological footprint concept, it would take the land area of about five more planet earths
for the rest of the world to reach current U.S. levels of consumption with existing technology. Put another way, if everyone consumed as much as the average American does today, the earth’s natural capital could support only about 1.3 billion people—not today’s 6.7 billion. In other words, we are living unsustainably by depleting and degrading some of the earth’s irreplaceable natural capital and the natural renewable income it provides as our ecological footprints grow and spread across the earth’s surface (Concept 1-3). For more on this subject see the Guest Essay by Michael Cain at ThomsonNOW?. See the Case Study that follows about the growing ecological footprint of China.
1-4 What Is Pollution and What Can We Do about It?
Pollution is any chemical or physical change in the environment that is harmful to humans or other living organisms. Pollutants can enter the environment naturally,
such as from volcanic eruptions, or through human activities, such as burning coal and gasoline.
The answers to these questions involve two different ways of dealing with pollution. One is pollution prevention, or input pollution control, which reduces or eliminates the production of pollutants. The other is pollution cleanup, or output pollution
control, which involves cleaning up or diluting pollutants
Environmental scientists have identified three problems with relying primarily on pollution cleanup. First, it is only a temporary bandage as long as population and consumption levels grow without corresponding improvements in pollution control technology. For example, adding catalytic converters to car exhaust systems has reduced some forms of air pollution. At the same time, increases in the number of cars and the total distance each travels have reduced the effectiveness of this cleanup approach.
Second, cleanup often removes a pollutant from one part of the environment only to cause pollution in another. For example, we can collect garbage, but the
garbage is then burned (perhaps causing air pollution and leaving toxic ash that must be put somewhere), dumped on the land (perhaps causing water pollution through runoff or seepage into groundwater), or buried (perhaps causing soil and groundwater pollution).
1-5 Why Do We Have Environmental Problems?
According to a number of environmental and social scientists, the major causes of these and other environmental problems are population growth, wasteful and unsustainable resource use, poverty, failure to include in market prices the environmental costs of producing and using goods and services, and too little knowledge of how nature works.
The harmful environmental effects of poverty are serious but those of affluence are much worse (Figure 1-8, top). The lifestyles of many affluent consumers in developed
countries and in rapidly developing countries such as India and China (Case Study, p. 13) are built upon high levels of consumption and unnecessary waste of resources. Such affluence is based mostly on the assumption—fueled by mass advertising—that buying more things will bring fulfillment and happiness.
This type of affluence has an enormous harmful environmental impact. It takes about 27 tractor-trailer loads of resources per year to support one American, or 7.9 billion truckloads per year to support the entire U.S. population. Stretched end-to-end, this number of trucks would reach beyond the sun!
1-6 What Are Four Scientific Principles of Sustainability?
‧ Reliance on Solar Energy: the sun warms the planet and supports photosynthesis used by plants to provide food for themselves and for us and other
animals.
‧ Biodiversity (short for biological diversity): the astounding variety of life forms, the genes they contain, the ecosystems in which they exist, and the natural services they provide have yielded countless ways for life to adapt to changing environmental conditions throughout the earth’s history.
‧ Population Control: competition for limited resources among different life forms places a limit on how much their populations can grow.
‧ Nutrient Cycling: natural processes recycle chemicals that plants and animals need to stay alive and reproduce.
2009年3月7日 星期六
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