Transcript Renewable and Nonrenewable Resources

Renewable and Nonrenewable
Resources
Tragedy of the commons





English villagers grazed their cattle on shared
pasture lands called commons.
Sometimes there were more cattle than the
pastures could hold.
Pastures were overused.
Overgrazing pastures damaged the land so bad
that the pastures could no longer support cattle.
Ecologists called this the “tragedy of the
commons”.
Classifying Resources

Environmental goods and services may be
classified as renewable and nonrenewable.


Renewable resources – regenerate if they are
alive or can be replenished by biogeochemical
cycles if they are non-living. Examples – fresh
water, trees, pasture
Nonrenewable resources – cannot be
regenerated by natural processes. Examples –
coal, oil and natural gas take too long to form
Sustainable Development


Human activities can affect the quality and
supply of renewable resources such as
land, forests, fisheries, air and fresh water.
Sustainable development is the way of
using natural resources without depleting
them and of providing for human needs
without causing long-term environmental
harm.
Land Resources




Land provides space for human
communities and raw materials for industry.
Soil can be a renewable resource if used
properly and damaged if mismanaged.
Fertile soils consist of good topsoil, sand,
clay and rock particles.
Good topsoil absorbs and retains moisture
and lets excess water to drain.
Land Resources



Plowing the land removes the roots that
hold the soil in place.
Soil erosion is increased.
A combination of farming, overgrazing,
and drought has turned fertile soils into
deserts – termed desertification
Sustainable development practices
to preserve land resources



Farming practices like contour plowing
reduces soil erosion.
Leaving stems and roots of previous crops
to hold the soil in place.
Planting a field with rye to protect the soil
from erosion.
Forest Resources

Forests are important for the products
they produce and the ecological functions
they perform.




Use wood for heating and cooking
“Lungs of the earth” – they remove carbon
dioxide and produce oxygen
Store nutrients and provide habitats
Moderate climate and limit soil erosion
Forest Resources



Can be considered renewable resources
Northeastern forests have been logged at
least once before.
Northwestern forests (old growth forests)
are non-renewable since it takes many
centuries to produce old-growth forests
Forest Resources

Effects of Deforestation – the loss of
forests



Severe erosion since soil is exposed to runoff
Erosion washes away nutrients in the soil
Grazing or plowing can cause permanent
changes to soils that can prevent the
regrowth of trees
Forest Resources

Forest Management strategies for
sustainable development



Selective cutting of trees to promote growth
of younger trees to preserve the forest
ecosystem.
Plant, manage, harvest, and replant tree
farms
Geneticists are breeding new, faster-growing
tree varieties for high quality wood
Fishery Resources


Fish and other animals are a valuable food
source
Overfishing


Harvesting of fish faster than they can replace
by reproduction
A true “tragedy of the commons”
Fishing Resources


Sustainable development
US National Marine Fisheries Service
created guidelines for commercial fishing.


Regulations help fish populations to recover
Specified how many fish and what size could
be caught in various parts of the oceans.
Fishery Resources

Aquaculture


The raising of aquatic animals for human
consumption
Could pollute water and damage aquatic
ecosystems
Air Resources




Air is a common resource that we all use.
Smog is a mixture of chemicals that occurs
as a gray-brown haze in the atmosphere.
Smog is considered to be a pollutant.
Pollutants are harmful materials that can
enter the biosphere through the land, air,
or water.
Air Resources



The burning of fossil fuels can release pollutants
that can cause smog and other problems in the
atmosphere such as nitrogen and sulfur
compounds.
If these compounds combine with water, then
acid rain is formed.
Acid rain can kill plants by damaging their leaves
and changing the chemistry of soils and standing
water ecosystems.
Freshwater Resources


Water is a renewable resource but is in a
limited supply.
Pollution threatens waters in many ways;


Discarded chemicals get into waterways
Sewage can get into the soils