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Chapter 1


Environmental Science
Course Code
Carl Mitchell

Chapter 1: An Introduction to Environmental Science
Our environment is more than just our surroundings:
Environment is more than water, land, and air; it is sum total of our surroundings
oIncludes all of Earths biotic components (living things like animals, plants, forests, soils,
people) and abiotic (nonliving things like physical constituents—continents, oceans,
clouds, rivers, icecaps)
Environment Canada: to preserve and enhance the quality of Canadas natural
environment, conserve our renewable resources, and protect our waters
Environmental science explores interactions b/w humans and the physical and biological world:
We depend on environment for air, water, food, shelter, and everything else essential for
Environmental science: study of how the natural world works, how our environment
affects us, and how we affect our environment
Natural resources are vital to our survival:
Natural resources: various substances and energy sources we need to survive
Renewable natural resources (sometimes called stock-and-flow resources): natural
resources (sunlight, wind, wave energy) that are replenishable over short periods
ogroundwater: regeneration limited by infiltration of groundwater to replenish an aquifer
osoil: physical and chemical weathering of rock to produce soil
Resource management: strategic decision making and planning aimed at balancing the
use of resource with it protection and preservation
Basic premise of renewable resource management—both living and non-living—is to
balance the rate of withdrawal from the stock with the rate of renewal or regeneration
Stock: harvestable portion of the resource
Nonrenewable natural resources: things like fossil fuels, mineral deposits—are in finite
supply and depletable (can take 100 million yrs. for natural geological processes to form an ore
deposit or a petroleum deposit)


Like fossil fuels, minerals are nonrenewable resources that are mined rather than
Human population growth has shaped our resource use:
Four significant periods of societal change triggered increases in pop. size
oPaleolithic (or Old Stone Age) period: happened approx. 2.5 million years ago…when
early humans gained control of fire and began to shape and use stones as tools with which
to modify their environment
oNeolithic period or Agricultural Revolution: transition from nomadic hunter-gatherer
lifestyle to a settled, agricultural way of lifechange occurred around 10000 to 12000
yrs. ago…People lived longer, had more children and were able to meet their nutritional
needs… agricultural revolution initiated a permanent change in the way humans relate to
the natural environment
oIndustrial revolution: began in mid-1700s…entailed shift from rural life, animal-
powered agriculture, and manufacturing by craftspeople, to an urban society powered by
fossil fuels…introduced improvements in sanitation, medical technology…introduction of
fossil fuel powered equipment steam engines, synthetic fertilizers, advances in plant and
animal breeding
oMedical-Technological Revolution: advances in medicine, sanitation, explosion of
communication technologies, shift to modern agricultural practices collectively knows as
Green Revolution have allowed more people to live longer
Resource consumption exerts social and environmental impacts:
IPAT model where I=P*A*T
oI is impact, P is population, A is affluence (level of consumption), T is technology
Carrying capacity and the “Tragedy of the Commons:
Carrying capacity: refers to the biological productivity of a system; it is a measure of the
ability of a system to support life
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