Human Impact on the Biosphere

Natural Resources

• Renewable resources

• Nonrenewable resources

Human activities affect the

quality and quantity of our

renewable and nonrenewable resources.

Sustainable Use of Resources

Sustainability

- intelligent and responsible management and conservation of our resources

Wastes

• Biodegradable wastes

– materials that can be broken down by microorganisms

– e.g. organic wastes (sewage and scraps of food)

• Non-biodegradable wastes

– can not be broken down by natural processes or are

broken down very slowly

– e.g. asbestos, glass, certain plastics and metals,

radioactive wastes and chemicals

• pollutants accumulate in the tissues of organisms

• further concentrated up the food chain (because the

biomass at a given trophic level is produced from a

much larger biomass ingested from the level below)

• e.g. pesticides and industrial waste products

DDT was once used to prevent malaria, yellow fever, lice and the spread of insect pests DDT poisoning in fish and birds

Biological Magnification

Land Resources

• Land pollution

• Soil erosion

• Desertification

• Deforestation

Water Resources

• Chemical Contamination

• Sewage Contamination

• Thermal Pollution

Air Resources

• Smog

• Acid Rain

• Greenhouse Effect

• Ozone Depletion

Biodiversity

• Ecosystem diversity

• Species diversity

• Genetic diversity

Threats to Biodiversity

• Demand for wildlife products

• Habitat destruction

• Pollution

• Introduction of exotic species

Conservation Efforts

• Reforestation

• Endangered Species and Protected Areas

• Recycling

• Cleaning up the environment and keeping it clean.