APES Tragedy of the Commons

Environmental Indicators that Guide Humans to Sustainability

1. Biological Diversity: Healthier ecosystems are resistant to disturbances 2: Food Production: Poor practices lead to soil degradation and water pollution 3: Global Surface Temperatures and CO2 Concentrations: Excessive CO2 increases global temperatures creating climate change 4: Human Population: Exponential population growth stresses our planet 5: Resources Depletion: Will this resource be available in the future

How can we live sustainably?

1. Preserve Nature 2. Sustainable Food Practices 3. Decrease energy use 4. Demographic Transition for Human population 5. Reduce, Reuse, and Recycle

How can we harvest sustainable yields?

1. Research & Planning: Reproductive abilities of a resource 2. Setting Quotas: Setting Limits 3. Requiring Permits: Manges harvesters 4. Focus on long term: Sustainability 5. Reforest: Replace trees that were harvested 6. Understanding to leave a resource better then when you found it

How can we shrink ecological footprint?

1. Use less energy 2. Build up instead of out 3. Reduce demands for paper and timber 4. Buy from local farms and eat less meat 5. Buy eco-friendly fish

Ecological Footprint

A measure of how many resources a person uses, expressed in an area of land

Fishing Down the Food Web & Trophic Cascades

As we deplete large, predatory fisheries, we move down to smaller fish species. Depletion of smaller fish populations limits fishery recovery and decreases food supply of marine mammals & seabirds

When does a population grow the most efficiently?

At 50% carrying capacity

5 Variables involved in calculating an ecological footprint

Carbon footprint: Energy used Built-up land: Settlements Forests: Timber and paper Cropland and Pasture: Food and fibers Fisheries: Seafood

Bottom Trawling

Especially harmful fishing method that involves dragging a large net along ocean floor Bycatch: unintended species like dolphins, whales, turtles caught in nets Stirs up ocean sediment (turbidity) & destroys coral reef structure. Decreases biodiversity by killing non-target species & removing coral reef habitat

Aquaculture Drawbacks

High density produces high concentration of waste (e. coli & eutrophication risks). High density increases disease risk, which can be transmitted to wild populations as well May introduce non-native species or GMOs to local ecosystem if captive fish escape Fish are fed antibiotics which can contaminate water via their waste

Externalities

Negative costs associated with human actions that aren't accounted for in the price We call these negative outcomes negative externalities, because they are costs that are negative costs of human actions that are externalized to someone else, usually the public or the taxpayer. The increased cost individuals pay for health care as a result of air pollution from factories and power plants is not paid for by the power plants, it is externalized to the people who suffer from the worsened asthma and bronchitis, and in reality, can be passed to the American taxpayer since some of the federal budget is directed to health care costs

Solutions for the Tragedy of the Commons

One solution is private or government ownership of land and other resources. If an individual purchases the land, or the government oversees its use, less degradation is likely because people generally take better care of their own things, because they suffer the consequences of ruining them. Government can impose fees or taxes for use of a resource (permit fees to graze cattle on public land, logging fees to the government, discharge permits) or a license to cut down trees in government owned forests. Government can enact laws that impose additional taxes, fines, or even criminal charges to companies or individuals that pollute shared air, soil, or water resources. Examples: Clean Air Act, Clean Water Act, Safe Drinking Water Act In the case of rangelands, which is land used for grazing of livestock, the BLM or Bureau of Land Management, collects grazing fees from ranchers, and monitors the state of rangelands in order to prevent and repair the effects of overgrazing

Overfishing 1975-85

Overfishing in period of 1975 - 1985 leads to sharp loss of profits from 1985 - 2018 Tragedy of the Commons: no incentive or penalty to prevent overfishing from 75' - 85'

Fisheries

Populations of fish used for commercial fishing

Aquaculture

Raising fish, or other aquatic species in cages/enclosures underwater Requires only small amount of water, space, and fuel Reduces risk of fishery collapse (90% population decline in a fishery) Doesn't take up any land space (compared to beef, pork, chicken)

Sustainability

The ability to use and maintain a resource indefinitely or for future generations

Sustainable Yield

The amount of a renewable resource that can be taken without reducing the available supply

Tragedy of the Commons

The tragedy of the commons suggests that individuals will use shared resources in their own self-interest rather than in keeping with the common good, thereby depleting the resources. Tendency of individuals to use shared/public resources in their own self-interest and thus degrading them. Examples include overgrazing, overfishing, air pollution, and overuse of groundwater/aquifers

Example problems caused by Tragedy of the Commons

The world's oceans are a common resource that is often overfished, which results in fishery collapse, such as the case with Atlantic Cod. This causes lost income for fishermen, and potentially even starvation in areas of the world heavily dependent on fish as a food source. Air pollution, comes from a variety of sources, including coal fired power plants. Coal fire plants emit particulate matter and sulfur dioxide, which are respiratory irritants that can exacerbate asthma, bronchitis, and cause increased healthcare costs. Farmers use pesticides to increase their yields, or the productivity of their crops, but pesticides can runoff land by heavy rains and enter nearby bodies of water or groundwater sources

Overgrazing

Too many animals grazing an area of land can remove all the vegetation (grass) which leads to topsoil erosion Animals also compact soil, decreasing H2O holding capacity → more erosion Desertification can occur if plants are killed by overgrazing & soil is compacted so much that it can't hold enough water anymore Rotational grazing (moving animals periodically) can prevent overgrazing. Can even increase growth of grass by distributing manure (natural fertilizer) & clipping grass back to size where growth is most rapid

Why does the Tragedy of the Commons Occur?

When no one person or group owns the land, no one feels responsible for maintaining it, and no one directly suffers the cost of depleting, degrading or overusing it.

Fishery Collapse

When overfishing causes 90% population decline in a fishery Population may never recover from fishery collapse due to: decreased biodiversity, inability to find mates, inbreeding depression Decreases genetic biodiversity of fish populations & species biodiversity of ocean ecosystems if species are lost from ecosystem Economic consequences: lost income for fishermen, lost tourism dollars for communities