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Human Population Growth & Habitat Destruction. US population growth. 1 b every........................... 8 seconds 1 d every......................... 12 seconds 1 i (net) every.................. 26 seconds Net gain of 1 every......... 13 seconds . 45,000 675,000.
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US population growth • 1 b every........................... 8 seconds • 1 d every......................... 12 seconds • 1 i (net) every.................. 26 seconds • Net gain of 1 every......... 13 seconds
45,000 675,000 zero pop change = April, 2240
Growth trend is not unique to US • 2004 estimates (CIA website) • India (1.07B) • 2.85 children/woman • 22.8 births/1,000 population • 8.38 deaths/1,000 population • ∆ 1.44% • Sudan (39.1M) • 4.97 children/woman • 35.79 births/1,000 population • 9.37 deaths/1,000 population • ∆ 2.64% • Greenland (58k) • 2.42 children/woman • 15.96 births/1,000 population • 7.7 deaths/1,000 population • ∆ -0.01%
Question 1 • Human population growth is sometimes blamed for the loss of biological diversity. Is this valid? • Is human population growth a concern for our environment?
Habitat Destruction • Almost all modern “environmental” problems are linked to human population growth – habitat destruction. • HD - Destruction of wildlife habitats by increasing pressure for land by fast-growing human populations, pollution and over-exploitation (EPA definition) • Examples: • Habitat conversion and fragmentation. • Reductions in habitat quality, overexploitation (harvesting, pet trading), (pollution, inc. global temps, soil erosion, introduced competitors/predators, etc.)
Habitat Conversion • Wisconsin forest fragmentation
After the conversion… Mauna Loa, Hawaii
Over harvesting • Rotenone abuse
Question 2 • How do we value the diversity of life or natural items? • How should we value them?
Why is biodiversity valuable? • Direct values $, meat, fibers • Indirect values • Aesthetics • Religious • Optional (e.g. rosy periwinkle) • See next slides: • Intrinsic value Vincristine - leukemia Vinblastine – Hodgkin’s disease
Question 3 • What choices do you make on a daily basis that are “good” for the environment? • What choices do you make on a daily basis that are “bad” for the environment?
Question 4 • Is the protection of the diversity of life a moral decision?
Question 5 & 6 • Should we slow human population growth? • How?