B 6.6 Effects of Humans on the Ecosystem

1. B 6.6 Effects of Humans on the Ecosystem

2. Our roles • Humans depend on the resources from Earth provided by geochemical cycles to provide: • Clean water • Breathable air • Good soil • Humans can affect these cycles in 3 ways • Population Growth • Technology • Consumption of Resources • Carrying capacity- maximum pop. size that is supported by resources • Energy, water, O2, and nutrients determine carrying capacity

3. Sustainability: A balancing act • Sustainability- meeting of needs for an organism to survive • To sustain human life there needs to be a balance between resources and carrying capacity • what the earth produces and what we consume • Factors that affect stability are the previous 3

4. Population Growth • Has grown exponentially and will continue to at a rapid rate • If we reach carrying capacity to slow this rate the death rate will be higher than the birth rate due to: • Food and water shortages • Pollution of environment • Spread of diseases • More people less food and water and more waste. • Soil is affected because the more land that is cleared the more good soil is lost (erosion) so food cannot be grown.

5. Population Growth • Deforestation cutting down trees because of demand for land • Less CO2 consumption and O2 production • Contributes to greenhouse effect • Erosion of soil • Human population has depleted clean water and fertile soil levels. Once these levels are low enough they can effect natural processes such as the water cycle, carbon cycle, nitrogen cycle etc.

6. Technology • Applied science has solved problems or help the needs of humans. This has benefited us but it has also contributed to pollution of air, water, and land. • We must now develop technology to provide cleaner energy sources, safer waste removal, and to clean up pollution. • 3 types of technology • Agricultural • Industrial • Alternative

7. Technology • Agricultural Technology • Improves ability to grow crops to keep up with population • Helps with soil erosion • Equipment contributes to air pollution • Fertilizers pesticides can have both pos. and neg. effects on environment • Industrial Technology • CFC’s contribute to depletion of ozone layer letting in UV rays • Batteries of cell phones and other devices are a waste concern • Burning of fossil fuels • Increase greenhouse gasses • Acid rain which affects soil and marine life

8. Technology • Alternative energy • Using natural renewable sources (wind, water, geothermal or solar energy) instead of fossil fuels to increase quality of the atmosphere • Nuclear energy does not impact environment but storage of waste does

9. Consumption of Resources • As population increases and technology expands so does the demand for resources. • Some renewable- produced at the same rate as consumed • Can be limiting factors • Some non renewable- cannot be produced at the same rate as consumed • Sustainable use of resources can be accomplished by reducing consumption, reusing products and recycling.