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The Environment –
Where do we fit in?
The Earth is composed of matter, the
amount of which is more or less
constant.
Matter is therefore recycled from one
form to the next.
Matter is recycled through these 3 layers…
The atmosphere (air)
The hydrosphere (water)
The lithosphere (crust or ground)
Why are atmospheric
gases important?
Their physical properties…
• Mitigates temperature extremities between night
and day:
 Absorbs ultraviolet radiation during the day, which
protects life on Earth
 The absorbed energy is emitted as heat during the
night
• Retain some of the heat radiated from the Earth’s
surface, thereby warming it
• Heated air is redistributed by convection from the
equator toward the poles
Their chemical properties…
• Most organisms require O2 to function
• Plants need CO2 for growth and food
production
• Nitrogen is found in all living things (DNA,
proteins, etc…), but atmospheric nitrogen
requires intermittent processes to be of
biological use
Why is the hydrosphere
important?
• Water is necessary for life, both for
sustenance and as a medium
• The freshwater on which terrestrial organisms
depend constitutes only 3% of Earth’s water,
but most of it exists as ice
How does the
hydrosphere recycle
matter?
Interacting with the atmosphere…
• Exchanges matter and energy to form the
Earth’s Climate System:
 Energy: The transfer of heat in a system converts
matter into other states (e.g. solid, liquid, gas);
the conversion of liquid water to vapour helps
cool the planet
 Matter: Water and gases that move between the
hydrosphere and atmosphere; this includes CO2
dissolved by cold water or absorbed by plankton
Interacting with the lithosphere…
• Oceans, specifically the plankton they contain,
are CO2 sinks; the plankton die, sink into the
water and eventually petrify, thus locking away
the CO2 they absorbed (Kender et al, 2009)
• Volcanic activity eventually releases some of the
trapped CO2, and so the hydrosphere works in
tandem with the lithosphere to regulate Earth’s
temperature to some extent
The combined interactions of the
atmosphere, hydrosphere and
lithosphere drive the hydrologic cycle,
which replenishes the relatively small
amount of liquid freshwater held in
aquifers, rivers and lakes
Why is the lithosphere
important?
• Interactions within the lithosphere (e.g. volcanic
activity) form land and regulate climate
• It is literally the ground on which terrestrial
organisms stand, thus facilitating their evolution
and the differentiation of species
• Interaction with the atmosphere and
hydrosphere forms soil, from which food grows,
allowing life to continue
Where do we fit in?
We live in the biosphere…
• This is the layer of the earth where living
organisms (including us!) exist and interact
with other biotic (living) and abiotic (nonliving) factors
• The biosphere includes the hydrosphere,
lithosphere and the atmosphere
Our place on this earth…
• If we were to compare the earth to an apple,
the biosphere would be the skin of the apple
• In this thin global membrane, where air, water,
soil and minerals are interconnected and
interact, life flourishes
How does the biosphere
support life?
Energy and matter are connected…
• Solar energy, the cycling of elements, and
gravity combine to sustain life on Earth
• Energy released by the sun provides the light
and heat needed to sustain life:
 It drives photosynthesis, the process whereby
green plants produce their own food
 It also drives the processes that recycle matter
Elements are cycled in the biosphere…
• The Earth does not receive significant inputs
of matter from space; therefore, the elements
that are present on Earth must be recycled;
this includes the nutrients that sustain life
such as carbon, nitrogen and phosphorus; and
of course, water
The nutrient cycles
How is water cycled
through the biosphere?
How is carbon cycled
through the biosphere?
How is nitrogen cycled
through the biosphere?
How is phosphorus cycled
through the biosphere?
That’s what happens
naturally. But what
happens when human
systems and processes
overlap with these natural
systems and processes?
We affect the air that we
breathe.
With the knowledge of how human
and natural processes overlap, in what
ways do you think we affected the
water that we drink?
The burning of fossil fuels (coal, oil,
natural gas) has increased
concentrations of CO2 in the
atmosphere
The clearing and burning of forests,
particularly in the tropics, has
substantially reduced one of our most
important carbon sinks
What are the effects of human
activities?
• The degradation and loss of natural
ecosystems associated with urban sprawl
• Alteration of natural element cycles and
energy flows
• Use of large areas for monoculture changes
the diversity and distribution of species,
risking the loss of species
How can we live
sustainably?
Start at home…
• Reduce waste
 A lot of waste can be recycled or composted, separate them
from the rest of your garbage
 Purchase products with less packaging
• Use less energy
 Use energy efficient appliances
 Turn off appliances after use and unplug those that are not
used continuously
• Use water efficiently
 Save the energy required to pump and purify
 Reduce the pressure on natural systems to replenish
…think sustainably…
• Look beyond the price tag
 Food costs energy to grow, harvest and transport
 Overpackaging is a sign of an insecure product
• Freshwater is not as abundant as you think
and hot water requires energy
 Recall how little of the Earth’s water is actually liquid
freshwater
…behave sustainably.
• Make use of public transit, biking and walking
to travel
• Support farmers’ markets and local businesses
• Consider the following example as a Canadian:
 Is a purse made by Aboriginals from fur more or
less sustainable than one made in India from
vinyl?
 What if you paid Fair Trade price for the fur purse?
We must change our ways. What
does being a “Green” Citizen mean
to you?
References
• Coates, D.R. (1981). Environmental geology. New York: Wiley.
• Erickson, J. (2001). Rock formations and unusual geologic
structures: exploring the earth's surface. New York: Facts on File.
• Kender, S., Peck, V. L., Jones, R. W., & Kaminski, M.A. (2009). Middle
Miocene oxygen minimum zone expansion offshore West Africa:
evidence for global cooling precursor events. Geology, 37(8), 699702.
• Thompson, G.R., & Turk, J. (2006). Earth science and the
environment (4th ed.). Belmont, CA: Thomson Brooks/Cole.