2.5M types of organisms on earth. Humans have greatest impact
Alterations of Ecosystems
- wartime forest defoliation
- oil spills
- ancient fire to kill reindeer/bison
- hunting mammals to extinction
- Maori in NZ
- Polynesias reduce forest cover and regional birds
- Europeans killed Galapagos turtles and African species for fashion
Environmental Stress
Environmental stress is the act of humans stressing environemnt
- deforestation
- pollutants
- toxic groundwater
- garbage in oceans
- canals
Water
Renewable source: resources that are replenished
Water is renewable but fresh water is not evenly distributed.
- sustained through hydrologic cycle - rain and snow from oceans -> landmasses
- kept in aquifers (water rocks)
- not safe, overuse -> saltwater gets in
- 3/4 of fresh water used is for farming
- California has debate for city vs farms (outsource food?)
- chemical pesticide -> groundwater poisoned
- water sources are uncertain
Politics in Middle East
Israel consumes 3x as much water as neighbors
- water sources conquered from neighbors
- bad relationship with Palestinian neighbors
Atmosphere
Thin lyaer of air lying above land and oceans.
Very resilient
- Krakatau and St. Helen were cleaned up p fast
- still gets gg10d by humans tho with industrialization
Global Warming
- tropospheric pollution
- greenhouse gases -> temps up
- up to 3.7 Celsius uip -> glacial ice, sea levels rise 6 inches
- greenhouse gases rise 2% per decade
Acid Rain
- pollutants in atmosphere -> acid rain formed by SO2 and NO are released by burning of fossil fuels
- wind flow -> acid rain patterns
Land
Deforestation
- trees are important for oxygen cycle
- in 1980’s 44% of tropical rainforests suffered and 1% logged every year -> gone in 90 years
- decreased somewhat by 2005
- still not completely understood
Waste
- solid waste
- sanitary landfill
- toxic waste
- radioactive waste
Biodiversity
- diversity of all aspects of life
- threatened
- 8% of plants
- 5% of fish
- 11% of birds
- 18% of mammals
- 650 species of plants and 480 animal in last 400 years