Chapter1: An introduction to environmental science
Our environment is more than just our surroundings
our environment is more than water, land, and air; it is the sum total of our
surroundings. It includes all of Earth's biotic components, or living things, as well as
the abiotic components, or nonliving things, with which we interact.
The fundamental insight of environmental science is that we are part of the natural
world, and our interactions with its other parts matter a great deal. (we are not
separated from the environment.)
Environment Canada: to preserve and enhance the quality of Canada's natural
environment, conserve our renewable resources, and protect our water resources.
Environmental science explores interactions between humans and the physical
and biological world.
Environmental science is the study of how the natural world works, how our
environment affects us, and how we affect our environment. We need to understand
our interactions with---and our role in---the environment.
Natural resources are vital to our survival
There are limits to many of our natural resources.
Renewable natural resources(stock-and-flow resources): sunlight, wind energy,
wave energy, geothermal energy. Other resources: agricultural crops, fresh water,
forest products, soils.(Can be renewed if we are careful not to deplete them or
damage them). Nonrewable natural resources: Crude oil, natural gas, coal,
copper, aluminum, and other metals.
Resource management is strategic decision making and planning aimed at
balancing the use of a resource with its protection and preservation. Premise:
balance the rate of withdrawal from the stock with the rate of renewal or
The stock is the harvestable portion of the resource.
Human population growth has shaped our resource use
Four significant periods of societal change appear to have triggered remarkable
increases in population size, concomitant with greatly increased environmental
1. 2.5 million years ago during the paleolithic(or Old Stone Age) period. Use
fire and shape stones.旧旧旧
2. 10,000 to 12,000 years ago (neolithic period/ Agricultural Revolution).
Transit from a nomadic, hunter-gatherer lifestyle to a settled, agricultural
3. mid 1700s. Industrial Revolution. Shift from rural life, animal-powered
agriculture to an urban society powered by fossil fuels. ALSO MARKED
THE BEGINNING OF INDUSTRIAL-SCALE POLLUTION AND OTHER
ENVIRONMENTALAND SOCIAL PROBLEMS. 旧旧旧旧
4. Today we are in the midest of a fourth transition. modern Medical-
Technological Revolution. new environmental challenges as a result of he
techonological advancements. Resource consumption exerts social and environmental impacts
I(impact on environment)=P(population)×A(affluence)×T(technology) Affluence: :
stands in for level of consumption.
Carrying capacity: a measure of the ability of a system to support life.
(environmental side: the number of individuals of a particular species that can
be sustained by the biological productivity of a given area of land)
Tragedy of the commons: each individual withdraws whatever benefits are
available from the common property as quickly as possible, until the resource
becomes overused and depleted. Ultimately, the carrying capacity of the area will be
exceeded, and its food production capacity will collapse.
Ecological footprint is a measure of the land and water required to sustain an
individual. It can be used to express the environmental impact of an individual or a
population. The capacity of a terrestrial or aquatic system to be biologically
productive and absorb waste, especially co2, is called biocapacity.
1. The ecological footprint of an average Canadian is approx 7.6 hectares.
2. People from wealthy nations have larger ecological footprints.
3. Two additional planet Earths for Western lifestyle.
Environmental science can help us avoid mistakes made in the past.
Civilization can crumble when pressures from population and consumption
overwhelm resource availability.
Five critical factors that determine the survival of civilizations: climate change/ hostile
neighbours/ trade partners/ environmental problems and the society's response to
Environmental science is an interdisciplinary pursuit
SUSTAINABILITY: leaving our children and grandchildren a world as rich and full
as the world we live in now./ not depleting earth's natural capital/ developing
solutions that are able to work in the long term./development that meets the need
of community without compromising the ability for others to meet their needs.
SUSTAINABLE DEVELOPMENT: is the use of renewable and nonrenewable
resources in a manner that satisfies our current needs without compromising
future availability of resources.
ENVIRONMENTALISM: is a social movement dedicated to protecting the natural
world---and, by extension, humans----from undesirable changes brought about by
ENVIRONMENTAL SCIENCE: the pursuit of knowledge about the workings of the
environment and our interactions with it.
CARRYING CAPACITY: a measure of the ability of a system to support life. In
terms of the number of individuals of a particular species that can be sustained by
the biological productivity of a given area of land.
BIOCAPACITY: The capacity of a terrestrial or aquatic system to be biologically
productive and to absorb waste, especially carbon dioxide. SYSTEMIC: human modification to a global scale system (i.e. Ozone/ atmosphere,
CUMULATIVE: changes of similar type in multiple regions add up to a global
impact. (i.e. deforestation, eroding soil)
ECOTONE: a transitional zone where ecosystems meet.
ECOSYSTEM: a distinctive biotic community and the abiotic systems with which it
key points to understand ecosystems are systems and cycles
BIOTA: living organisms.
ABIOTA: non-living components of the environment.
BIOTIC COMMUNITIES: identifiable groupings of living things---animals, plants,
microbes, etc. (share overlapping 重重重habitats)
ORGANIC MATTER: the material from which living things and formerly living
things is made.( generally has Carbon= Carbon bonds/ chemical structure/ usually
includes Hydrogen atoms/ may include other elements such as nitrogen , oxygen 重
重, sulphur or phosphorous .) 重
INORGANIC MATTER: no Carbon. compounds of mineral 重重重, rather than biological
origin. It's also fundamentally important for supporting life.
BIOMES 重重重重: Biomes are often defined by abiotic factors such as climate, relief,
geology, soils and vegetation. / large regions of similar biotic communities.
classified by major vegetation types. Climate is a major factor determining the distribution of
SPECIES: groupings of similar organisms that produce fertile offspring when they
HABITAT: particular physical and biological (or abiotic and biotic) conditions to
which a species is adapted (where the species lives)/ natural environment
ECOLOGICAL NICHE: The ecological niche includes both the animal's or plant's physical
habitat and how it has adapted to life in that habitat./ a summary of everything that an organism
does: a species' use of resources and its functional role in its community.
some species are specialists(have very specific requirements, so are only found in certain conditions)
and generalists(have a broad tolerance to different conditons, thus can survive in a range of habitats with different resources)
Organisms may have to compete for resources, which limits the niche that they can occupy
SYSTEM: a network of relationships among components that interact with and influence one
another through the exchange of energy, matter or information.(i.e. body, university)
open system(much more common): interact with elements outside the system--energy and
matter are freely exchanged with surroundings. i.e. ocean
closed system: energy is free to come and go but matter is contained./ systems that receive
inputs and produce outputs of energy, but not matter. i.e. Earth as a whole. NOTHING
DISAPPEARS, EVERYTHING DISPERSES
IN NATURE NO SYSTEM IS TRULY, PERFECTLY CLOSED.
energy inputs: solar radiation, heat released by geothermal activity, organismal metabolism,
fossil fuel combustion...
information inputs: sensory cues from visual, chemical, magnetic or thermal signals.
matter inputs: seeds dispersed, migratory animals deposit waste, plant convert carbon.
CYCLE: shape the landscapes around us and guide the flow of key chemical elements and
compounds that support life and regulate climate.
FEEDBACK LOOP: relationships between parts of the system/ a system's output can serve as
input to that same system.
NEGATIVE FEEDBACK LOOP: a feedback loop in which output of one type acts as input that
moves the system in the opposite direction. Neutralize each other's effects, stabilizing the
system./ counteracts 重重 or slows down a change that is occurring. common
重重重 重重重重重重重 重重重重重重重重重重重重重重重重重重重重重重重重重重重重重重重重重重predator-prey system: the population of predator and prey
rise and fall in response to one another.
POSITIVE FEEDBACK LOOP: a feedback loop in which output of one type acts as input that
moves the system in the same direction. Drive the system further toward one extreme or
another./ reinforces or speeds up a change that is occurring. rare
重重重 climatic warming leading to the melting of ice, exposes underlying darker surfaces. Darker
absorb more sunlight, so melting more quickly.
ECOSYSTEM ECOLOGY: the study of energy and nutrient flows among living and nonliving
components of systems.
AUTOTROPHS 重重重重 producers: organisms that create organic matter via photosynthesis/ plus
some chemosynthetic 重重重重重 bacteria.
HETEROTROPHS 重 重 重 重 consumers: must consume organic material produced by other
organisms./ Organisms that derive their food energy from other organisms. are called
LANDSCAPE: group of interacting ecosystems CAPTAL: term originating in economics/ originally referred to money in excess of that needed to
meet one's own needs/ has been expanded to include human/social/cultural/ capital
ECOSYSTEM CAPITAL: goods and services humans derive 重重 from the natural environment.
EXTERNALITY: a cost borne 重重 by someone not involved in the transaction 重重.
ECOLOGICAL COMMUNITIES: a group of populations or organisms that live in the same place at
the same time.
PHOTOSYNTHESIS: plants take C/H/O/N/P and S add energy and create complex organic
provides energy that may be utilized (metabolized) by other living organisms.
ENTROPY: a state of disorder. when you stop adding energy to a system, entropy increases and
eventually the system stops
Organic material stores energy: when you burn a log in a fireplace