Chapter 1 Key Themes in Environmental Sciences

Major Themes of Environmental Science  Human population growth  An urbanizing world  Sustainability of our population and all of nature  People and nature  A global perspective  Science and values  Human population growth  An urbanizing world  Sustainability of our population and all of nature  People and nature  A global perspective  Science and values

Human Population Growth  The human population grew at a rate unprecedented in history in the twentieth century.  Population growth is the underlying environmental problem.  Famine is one of the things that happen when a human population exceeds its environmental resources. An example is African Famine.  The human population grew at a rate unprecedented in history in the twentieth century.  Population growth is the underlying environmental problem.  Famine is one of the things that happen when a human population exceeds its environmental resources. An example is African Famine.

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An Urban World  When the impact of technology is combined with the impact of population, the impact on the environment is multiplied.  In an increasingly urban world, we must focus much of our attention on the environments of cities and on the effects of cities on the rest of the environment.  When the impact of technology is combined with the impact of population, the impact on the environment is multiplied.  In an increasingly urban world, we must focus much of our attention on the environments of cities and on the effects of cities on the rest of the environment.

Sustainability and Carrying Capacity  What is the maximum number of people the Earth can sustain?

Sustainability  Sustainable resource harvest  An amount of a resource that can be harvested at regular intervals indefinitely  Sustainable ecosystem  An ecosystem that is subject to some human use, but at a level that leads to no loss of species or of necessary ecosystem functions  Sustainable resource harvest  An amount of a resource that can be harvested at regular intervals indefinitely  Sustainable ecosystem  An ecosystem that is subject to some human use, but at a level that leads to no loss of species or of necessary ecosystem functions

Science and Values  To make decisions about an environmental problem we:  Know what is possible based on science  Choose the best option based on our values  To make decisions about an environmental problem we:  Know what is possible based on science  Choose the best option based on our values

Precautionary Principle  Precautionary Principle states that we should not wait for scientific proof before taking action to prevent environmental damage.  Ex. San Francisco  Precautionary Principle states that we should not wait for scientific proof before taking action to prevent environmental damage.  Ex. San Francisco