Renewable and Renewable and Nonrenewable ResourcesNonrenewable Resources

Tragedy of the commonsTragedy of the commons

English villagers grazed their cattle on English villagers grazed their cattle on shared pasture lands called commons.shared pasture lands called commons.

Sometimes there were more cattle than Sometimes there were more cattle than the pastures could hold.the pastures could hold.

Pastures were overused. Pastures were overused. Overgrazing pastures damaged the land Overgrazing pastures damaged the land

so bad that the pastures could no longer so bad that the pastures could no longer support cattle.support cattle.

Ecologists called this the “tragedy of the Ecologists called this the “tragedy of the commons”.commons”.

Classifying ResourcesClassifying Resources

Environmental goods and services may Environmental goods and services may be classified as renewable and be classified as renewable and nonrenewable. nonrenewable. Renewable resources – regenerate if they are Renewable resources – regenerate if they are

alive or can be replenished by alive or can be replenished by biogeochemical cycles if they are non-living. biogeochemical cycles if they are non-living. Examples – fresh water, trees, pasture Examples – fresh water, trees, pasture

Nonrenewable resources – cannot be Nonrenewable resources – cannot be regenerated by natural processes. Examples regenerated by natural processes. Examples – coal, oil and natural gas take too long to – coal, oil and natural gas take too long to form form

Sustainable DevelopmentSustainable Development Human activities can affect the Human activities can affect the

quality and supply of renewable quality and supply of renewable resources such as land, forests, resources such as land, forests, fisheries, air and fresh water.fisheries, air and fresh water.

Sustainable development is the way Sustainable development is the way of using natural resources without of using natural resources without depleting them and of providing for depleting them and of providing for human needs without causing long-human needs without causing long-term environmental harm.term environmental harm.

Land ResourcesLand Resources

Land provides space for human Land provides space for human communities and raw materials for communities and raw materials for industry.industry.

Soil can be a renewable resource if used Soil can be a renewable resource if used properly and damaged if mismanaged.properly and damaged if mismanaged.

Fertile soils consist of good topsoil, Fertile soils consist of good topsoil, sand, clay and rock particles. sand, clay and rock particles.

Good topsoil absorbs and retains Good topsoil absorbs and retains moisture and lets excess water to drain.moisture and lets excess water to drain.

Land ResourcesLand Resources

Plowing the land removes the roots Plowing the land removes the roots that hold the soil in place.that hold the soil in place.

Soil erosion is increased.Soil erosion is increased. A combination of farming, A combination of farming,

overgrazing, and drought has turned overgrazing, and drought has turned fertile soils into deserts – termed fertile soils into deserts – termed desertificationdesertification

Sustainable development Sustainable development practices to preserve land practices to preserve land

resourcesresources Farming practices like contour Farming practices like contour

plowing reduces soil erosion.plowing reduces soil erosion. Leaving stems and roots of previous Leaving stems and roots of previous

crops to hold the soil in place.crops to hold the soil in place. Planting a field with rye to protect Planting a field with rye to protect

the soil from erosion.the soil from erosion.

Forest ResourcesForest Resources

Forests are important for the Forests are important for the products they produce and the products they produce and the ecological functions they perform.ecological functions they perform. Use wood for heating and cookingUse wood for heating and cooking ““Lungs of the earth” – they remove Lungs of the earth” – they remove

carbon dioxide and produce oxygencarbon dioxide and produce oxygen Store nutrients and provide habitatsStore nutrients and provide habitats Moderate climate and limit soil erosionModerate climate and limit soil erosion

Forest ResourcesForest Resources

Can be considered renewable resources Can be considered renewable resources

Northeastern forests have been logged Northeastern forests have been logged at least once before.at least once before.

Northwestern forests (old growth forests) Northwestern forests (old growth forests) are non-renewable since it takes many are non-renewable since it takes many centuries to produce old-growth forestscenturies to produce old-growth forests

Forest ResourcesForest Resources

Effects of Deforestation – the loss of Effects of Deforestation – the loss of forestsforests Severe erosion since soil is exposed to Severe erosion since soil is exposed to

runoffrunoff Erosion washes away nutrients in the soilErosion washes away nutrients in the soil Grazing or plowing can cause permanent Grazing or plowing can cause permanent

changes to soils that can prevent the changes to soils that can prevent the regrowth of treesregrowth of trees

Forest ResourcesForest Resources

Forest Management strategies for Forest Management strategies for sustainable developmentsustainable development Selective cutting of trees to promote Selective cutting of trees to promote

growth of younger trees to preserve the growth of younger trees to preserve the forest ecosystem.forest ecosystem.

Plant, manage, harvest, and replant tree Plant, manage, harvest, and replant tree farmsfarms

Geneticists are breeding new, faster-Geneticists are breeding new, faster-growing tree varieties for high quality growing tree varieties for high quality woodwood

Fishery ResourcesFishery Resources

Fish and other animals are a valuable Fish and other animals are a valuable food sourcefood source

OverfishingOverfishing Harvesting of fish faster than they can Harvesting of fish faster than they can

replace by reproductionreplace by reproduction A true “tragedy of the commons”A true “tragedy of the commons”

Fishing ResourcesFishing Resources

Sustainable developmentSustainable development

US National Marine Fisheries Service US National Marine Fisheries Service created guidelines for commercial fishing.created guidelines for commercial fishing. Regulations help fish populations to recoverRegulations help fish populations to recover Specified how many fish and what size could Specified how many fish and what size could

be caught in various parts of the oceans. be caught in various parts of the oceans.

Fishery ResourcesFishery Resources

AquacultureAquaculture The raising of aquatic animals for The raising of aquatic animals for

human consumptionhuman consumption Could pollute water and damage aquatic Could pollute water and damage aquatic

ecosystemsecosystems

Air ResourcesAir Resources

Air is a common resource that we all use.Air is a common resource that we all use. Smog is a mixture of chemicals that Smog is a mixture of chemicals that

occurs as a gray-brown haze in the occurs as a gray-brown haze in the atmosphere.atmosphere.

Smog is considered to be a pollutant.Smog is considered to be a pollutant. Pollutants are harmful materials that can Pollutants are harmful materials that can

enter the biosphere through the land, air, enter the biosphere through the land, air, or water.or water.

Air ResourcesAir Resources

The burning of fossil fuels can release The burning of fossil fuels can release pollutants that can cause smog and other pollutants that can cause smog and other problems in the atmosphere such as problems in the atmosphere such as nitrogen and sulfur compounds.nitrogen and sulfur compounds.

If these compounds combine with water, If these compounds combine with water, then acid rain is formed. then acid rain is formed.

Acid rain can kill plants by damaging their Acid rain can kill plants by damaging their leaves and changing the chemistry of soils leaves and changing the chemistry of soils and standing water ecosystems. and standing water ecosystems.

Freshwater Freshwater ResourcesResources

Water is a renewable resource but is Water is a renewable resource but is in a limited supply.in a limited supply.

Pollution threatens waters in many Pollution threatens waters in many ways;ways; Discarded chemicals get into waterwaysDiscarded chemicals get into waterways Sewage can get into the soilsSewage can get into the soils