Tragedy of the Commons

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2 Tragedy of the Commons 1968, Garrett Hardin The tendency of a shared, limited resource to become depleted because people act from self-interest for short term gain

3 Externality A cost or benefit of a good or service not included in the purchase price of that good or service - Negative - Positive

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5 Maximum Sustainable Yield (MSY) The maximum amount of a renewable resource that can be harvested without compromising the future availability of that resource - Amount of harvest that keeps it at half of carrying capacity

6 Maximum Sustainable Yield (MSY) - Above MSY: depletion - Below MSY: overpopulation

7 Public Lands 11% of Earth is protected public land

8 National Parks Managed for scientific, educational, recreational use, beauty, or unique landforms

9 Managed Resource Protected Areas Sustained use of biological, mineral, and recreational resources

10 Habitat/Species Management Areas Actively managed to maintain biological communities

11 Strict Nature Reserves & Wilderness Areas - Established to protect species and ecosystems

12 Protected Landscapes & Seascapes - Combine the nondestructive use of natural resource with opportunities for tourism and recreation

13 National Monuments - Set aside to protect unique sites of special natural or cultural interest

14 National Park Service Recreation and conservation

15 United States Forest Service Timber harvesting, grazing, and recreation

16 Fish & Wildlife Service Wildlife conservation, hunting, and recreation

17 Bureau of Land Management Grazing, mining, timber harvesting, and recreation

18 Rangelands Description: dry, open grasslands Managed by: BLM Use: primarily the grazing of cattle Major environmental impacts: overgrazing

19 Taylor Grazing Act of 1934 Passed to halt overgrazing Converted rangelands into a permit-based grazing system to limit # of grazing animals to prevent TotC However, the low cost of permits still encourages overgrazing

20 Overgrazing Continues BLM is not always successful in its quest to manage rangeland because rangeland managers aren t given detailed guidance and do not require the involvement of environmental scientists

21 Forests Description: trees and woody vegetation Managed by: USFS Use: timber Major environmental impacts: intensive logging (habitat destruction, erosion)

22 Clear Cutting removing all or almost all of the tree within an area Pros - economical, easy harvesting, entire area is replanted (same age, maximum sunlight) Cons- wind & soil erosion, mudslides, replanting uses fire and herbicides, logging roads

23 Selective Cutting Removes single trees or relatively small number of trees from among many in a forest Pros - trees can reseed, ideal for shade-tolerant species Cons - still need to construct logging roads

24 Forests Why is it hard for the USFS to manage forests? We need timber but all logging causes biodiversity loss

25 Forests What is the natural role of fires in many ecosystems? Nutrient recycling & regeneration How do human policies aimed at preventing fire actually make fires worse? Led to accumulation of dead biomass which made for an accidental fire that was much worse

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27 National Park Description: scenic views, unusual landforms Managed by: NPS Use: scientific, educational, aesthetic, and recreational Major environmental impacts: islands of biodiversity still affected by air/water pollution, human overuse (ex: ATVs)

28 Wildlife Refuges & Wilderness Areas Description: various ecosystems Managed by: FWS Use: protect wildlife Major environmental impacts: people still want their resources

29 Wildlife Refuges vs Wilderness Areas Although they are categorized with wilderness areas, wildlife refuges are not nearly as protected as wilderness.

30 Wilderness Areas Normally banned activities such as mining are allowed in national wilderness areas if they were previously permitted before the wilderness designation

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32 Urban Sprawl Creation of urbanized areas that spread into rural areas and remove clear boundaries between the two

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35 Urban Sprawl Environmental impacts of urban sprawl - people travel more, suburbs use more land, loss of farmland 4 causes - automobiles, living costs, urban blight, and government policies

36 Urban Sprawl 1) Automobiles make transportation rapid & comfortable 2) Houses are cheaper in the suburbs

37 Positive Feedback Loop vs Negative Feedback Loop

38 3) Urban Blight As people move away from a city to suburbs and exurbs, the city often deteriorates, causing more people to leave

39 4) Govt Policies - Highway Trust Fund Pays for the construction and maintenance of roads and highways More roads means more gas taxes that pay for more roads so more travel so more gas... Has created induced demand (the supply of a good causes demand to grow)

40 10 Principles of Smart Growth Create mixed land uses Create a range of housing opportunities & choices Create walkable neighborhoods Encourage community and stakeholder collaboration in development decisions 5. Take advantage of compact building design

41 10 Principles of Smart Growth 6. Foster distinctive communities with a strong sense of place 7. Preserve open space, farmland, natural beauty, and critical environmental areas 8. Provide public transportation 9. Strengthen & direct development toward existing communities 10. Make development decisions predictable, fair, and cost efficient

42 Infill Development that fills in vacant lots within existing communities rather than expanding into new land outside the city

43 Urban growth boundary Place restrictions on development outside a designated area

44 Eminent domain A principle that grants government the power to acquire a property at fair market value even if the owner does not wish to sell it