Key Themes in Physical Geography

July 6th, 2009

The Environmental Problem

• Human population growth– 1 AD 100 million– 1960 3 billion– 2008 6.6 billion– 2040 9 billion

• Estimates of Earth’s carrying capacity: 2.5 billion to 40 billion

• Population bomb

The Environmental Problem

• Human population growth has not been steady– African famines

• Famine is a consequence of overpopulation and exceedence of environmental resources

– The Black Death

The Environmental Goal

• Sustainability – refers to resources and their environment – ensuring that future generations have equal opportunity to the resources that our planet offers

• Sustainable resource harvest – the same quantity of a resource can be harvested each year for an unlimited or specified amount of time without decreasing the ability of the resources to produce the same harvest level

• Sustainable ecosystem – ecosystem from which we are harvesting a resource that is still able to maintain its essential functions and properties

The Environmental Goal

• Sustainable global economy – the careful management and wise use of the planet and its resources

• Under present conditions, the global economy is not sustainable

• Characteristics of a sustainable economy– Populations living in harmony with the natural environment– An energy policy that does not alter the natural environment– A plan for renewable resources– A social, political, and legal system dedicated to sustainability

The Environmental Goal

• To achieve a sustainable global economy:– Develop an effective population-control

strategy– Completely restructure our energy programs– Institute economic planning– Implement social, legal, political, and

education changes

Carrying Capacity

• Carrying capacity – the maximum number of individuals of a species that can be sustained by an environment without decreasing the capacity of the environment to sustain that same amount in the future

• Desirable human carrying capacity depends of quality of life

Precautionary Principle

• When there is a threat of serious, perhaps even irreversible, environmental damage, we should not wait for scientific proof before taking precautionary steps to prevent potential harm to the environment