Chapter 27 – Human Impacts on Earth Resources

Resources and Organisms• The oxygen you breathe in and the carbon

dioxide you exhale are examples of natural resources you use everyday

• Most organisms have adapted to their particular environment and live in balance with it

• Other organisms change the environment to meet their needs– Some positive, some negative

Asian Carp

• Carp 1• Carp 2

Resources and Population Growth

• Any type of organism can have an impact if the population becomes too large

• As population grows, the demand for resources increases

• Population growth is defined as an increase in population size over time

J-shaped Curve

• Normally, a growing population can be shown by a J-shaped curve

Limits to Population Growth

• Earth’s resources are limited, so population cannot grow forever

• Limiting factors can be: food, water, or clean air

• Number of organisms an environment can support is its carrying capacity

S shaped curve

Carrying capacity

Environmental Factors

• Storms, extreme changes in temp, droughts, floods and pollution can all affect population size

• Disease, parasites, and lack of food can also affect it

Urban Development

• 70% of the North American population live in either urban or suburban areas

• Development of land or new construction can cause environment problems– Destroys old habitats

• Development also takes away from farmland and adds pressure to remaining farmland– Increase chance of flooding because of increase of

asphalt and concrete– Increase in solid waste

Solutions

• Developers put barriers around new construction

• Modern landfills