TOPIC 7 - HUMAN IMPACT (REGENTS)

Material cycles

• carbon/oxygen cycle (photosynthesis/respiration)

• Water cycle (evaporation, condensation, precipitation, transpiration)

• Nitrogen cycle (N2, nitrogen fixing bacteria, plants, animals, waste)

Biodiversity

A measurement of the degree to which species vary within an ecosystem. the more species present in an ecosystem the higher the biodiversity

How have humans affected biodiversity

• Cutting down trees (for wood)

• Planting all of the same crop in an area (loss of biodiversity)

• Removed vegetation for houses, parking lots, roads, etc.

• Killed organisms and destroyed the food web (because all organisms are linked to one another in one way or another)

Renewable resources

Resources that can replenish themselves if not abused (planting of trees)

Non renewable resources

Resources that take a long time to replace or form (coal/oil)

Preserving resources

• reduce: cut down on the amount used (smaller packaging)

• reuse: use it for another application (old tires as flower planters)

• recycle: can be used to make the product again (pop bottles)

Pollution

Harmful change in the chemical makeup of the air, water, or soil

Human activities & loss of diversity

• Direct Harvesting - the destruction or loss of a species by over hunting.

• Land Use - finding the best way to live in the environment- building around trees instead of cutting them down and planting new ones.

• Habitat Destruction - destroying a part of the natural environment.

• Deforestation - removing forests for wood or clearing trees for farms.

• Imported Species (invasive species or exotic species) example: purple loosestrife; zebra mussels;
  dandelions

Impact of technology & industrialization

• Industrialization- increases pollution of air and water- uses more energy, water, fossil and nuclear fuels.

• Water pollution-from sewage, wastes from homes and factories and animal wastes

• Toxic wastes- DDT

• Thermal pollution- Heat Pollution

• Human overpopulation

• Air pollution- burning fossil fuels

Acid rain

Sulfur and nitrogen compounds in air pollution dissolve in the moisture of the atmosphere to form acids, causing rain to have a low pH (acidic), it can kill trees and destroy historical artifacts

Global warming

An increase in the earth’s temperature caused by an increase in greenhouse gases

Greenhouse effect

Caused by increasing amounts of CO2 in the atmosphere caused by the increasing use of fossil fuels for energy

Ozone depletion

Hope in ozone layer caused by use of fluorocarbons

Ozone

Acts as a sun block for all organisms on earth. Damage causes skin cancer