Transcript Linear Vs. Exponential Growth

APES
UNIT I: SUSTAINABILITY
Chapter 1-Studying the State of Our Earth
FRQ #1
1Q=10 points
40points total for FRQ= 40% of AP grade
P29 #2. The study of environmental science sometimes
involves examining the overuse of environmental
resources.
• (a) Identify one general effect of overuse of an
environmental resource. (3 points)
• Possible answers could include cutting down trees,
which leads to massive erosion. Other answers could
be loss of soil, which caused food production to
decrease and overuse of needed water resources.
• (b) For the effect you listed above, describe a more
sustainable strategy for resource utilization. (3 points)
• Possible answers could include any of the
sustainable development ideas from page 12. For
example, practices such as conserving and finding
alternatives to nonrenewable resources as well as
protecting the capacity of the environment to
continue to supply renewable resources. Recycling
and reuse are other possible answers with a suitable
discussion of the strategy.
• (c) Describe how past events from Easter Island can
indicate environmental issues on Earth today. (4 points)
• Answers can include a discussion of how
environmental scientists believe that there are limits
to the supply of clean air and water, nutritious foods,
and other life-sustaining resources our environment
provides. They also feel there is a point at which
Earth will no longer be able to maintain a stable
climate.
Motivation Monday
• If you don't know the struggle, you don't know the
strength.
• If it doesn’t challenge you, it won’t change you.
• The more you challenge yourself, the smarter you
become!
Objectives
1. Define the field of environmental science and discuss its
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importance
Identify ways in which humans have altered and continue to
alter our environment
Describe key environmental indicators that help us evaluate
the health of our planet
Define sustainability and explain how it can be measured using
the ecological footprint
Explain how the scientific method is used to study
environmental problems
Describe some of the unique challenges and limitations of
environmental science.
I. Studying the environment
• Environmental Studies:
1) Human activities can
affect environment in
complex and
unexpected ways
2) Environmental science
can be controversial
3) Findings are not
always as clear cut as
they appear to be
http://www.npr.org/2014/05/06/30910
1579/drought-stricken-texas-townturns-to-toilets-for-water
Environmental Indicators
• Ecosystem Services: Benefits we receive from the
environment (ecosystem)
• Environmental Indicators: describes or gives
insight into current state of the environment; used
to track state of environment (land, water, air)
• Sustainability: living in such a way that resource
use does not deprive future generations of that
resource; finding alternatives and protecting
capacity of environment to continue to supply
resources; the capacity to endure
• Stewardship: responsible use and protection of
the natural environment.
Page 8 in Text
Environmental indicators help us describe the current state of an environmental system.
What is Biodiversity?
• Quantity and variety of life forms.
• 3 Levels: genetic, species, ecosystem.
Genetic Diversity
• A measure of the genetic variation among
individuals in a population.
• Populations with high genetic diversity are
better able to respond to environmental
change than populations with lower genetic
diversity.
Species Diversity
• The number of species in a region or in a
particular type of habitat.
• Species- a group of organisms that is
distinct form other groups in form,
behavior or biochemical properties.
Individuals in a species can breed and
produce fertile offspring.
Ecosystem Diversity
• A measure of the diversity of ecosystems or
habitats that exist in a particular region.
Background Extinction rate
• The average number of species going extinct over
a long period of time.
Carrier pigeon
• Some scientists estimate more than 10,000
species are currently going extinct each
year…this is 5000 times the background rate.
• Cause: habitat destruction and degradation.
Three principles of sustainability
Reliance on
solar energy
Biodiversity
Chemical cycling
Resources
Defined by how quickly we can use them up or how well
nature can replenish them after we use them.
Perpetual: Supply continuous; cannot be depleted on a human
time scale. Solar
Potentially renewable: takes several days to several hundred
years to be replenished through natural processes. Soil,
forests, freshwater, fish populations, fresh air. Highest rate at
which they can be used is sustainable yield.
Non-Renewable: Exist in a fixed quantity in earth’s crust;
exhaustible. Geologic processes create these resources on a
time scale of millions to billions of years. Fossil fuels, metallic
mineral resources, non-metallic mineral resources.
Fig. 1-14, p. 20
II. Measuring Human Impact on the
Environment
• Ecological Footprint: amount of
biologically productive land and water
needed to provide the people in a
particular country or area with an
indefinite supply of renewable
resources and to absorb and recycle
wastes and pollution associated with
resource use.
•I = PxAxT
• Impact = population x Affluence x technological impact
Tragedy of the Commons: Overexploiting
Shared Renewable Resources
• Private property: individuals or companies own
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rights to land, minerals or other resources
Common property: rights to certain resources are
held by large groups or individuals
Open-access renewable resources: owned by no
one and available for use by anyone at little or no
charge.
Garrett Hardin 1968 outlined the misuse of openaccess resources- tragedy of the commons
Solutions: 1) use resource at a rate well below
sustainable yield or 2) convert to private ownership
Living in an Exponential Age
Linear Vs. Exponential Growth
• Linear-Quantity increases
by a constant amount per
unit of time. Ex. 1,2,3,4,5
• Exponential-Quantity
increases by a fixed
percent of whole in a given
time-increase is
proportional to what is
already there.
Doubling time and the Rule of 70.
• To find doubling time of a quantity growing at a given
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annual percentage rate, divide percentage into 70.
Examples:
$100 invested at a rate of 5% = doubling time
70/ 5% = 20 year double time
Population of 1 million growing at a rate of 3% =
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DT
70/ 3% = 23.3
To get annual growth rate, divide 70 by doubling time
Oil consumption doubles every 50 years =
rate of
growth
70/50=1.4%
Percent Change
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Percent Change-increase or decrease-can be calculated using the following formula:
Change in Quantity X 100%
Original Quantity
Example: You consumed 800 gallons of gas in 2014 and 1200 gallons in 2015. What
is the percent increase in your gasoline consumption?
800 1200  400 / 800  .5X100  50%
If gasoline is $3.00/gallon how much more did you spend on gas?
$3
400 gal
 $1200
1gal
Example: A deer population goes from 1000-3000- what is the percent change?
1000  3000  2000 / 1000 X100  200%
Scientific Notation and Dimensional Analysis
• The study of Environmental Science involves analysis of data,
and making conclusions about environmental impact based on
calculations with that data. You will NOT be allowed to use
calculators on unit problems, tests, or the national exam and
should practice using scientific notation and utilizing
dimensional analysis to convert units.
• Example: Your car gets 20 mpg and you drive 40,000 miles.
How many gallons of gas have you burned?
4 x 104 miles
1 gallon
2.0 x 101 miles
=
4 x 104
= 2 x 103 gallons
2 x 101
OR 2000 gallons
Understanding Metric Conversion
Area Conversions
• Several FRQ’s from the past have had students calculate
the number of acres and/or hectares of land needed to
feed or grow a certain crop.
• multiply
• Acres
• Hectares
by this number
0.4047
2.47
to covert to the following:
Hectares
Acres
Understanding Metric Conversion, Cont.
Length Conversions
• multiply
• Feet
• Meters
• Kilometers
• Miles
by this number to covert to the following:
0.3048
Meters
3.2808
Feet
0.62
Miles
1.609347
Kilometers
• International System of measurement. Scientists refer to
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this system as SI, because they felt that the world needed
a common means of measurement. This has made things
much easier for worldwide communication.
convert all metric units by moving the decimal to the left or
to the right
Two Rules for the International System
No fractions are involved with the metric system (SI).
No Naked Numbers! DON’T just write down a number like
56.8 . I don’t know if that means mm, cm, m, or km.
*ALWAYS use units (labels).
• King Henry Died Unfortunately Drinking Chocolate Milk
Kilo Hecto Deca Unit
Deci
Centi Milli
• Convert 56.8 m to millimeters
• Hint- Move the decimal from the U (unit or meter) three
spaces to the right (millimeter)
• 56.8 m ------------------------56,800 mm
• Convert 4,885 cm to kilometers
• Hint- Move the decimal from the cm (centimeter) five
spaces to the left (kilometer).
• 4,885 cm --------------------0.04885 km
Mass (weight) Conversions
Temperature Conversions
III. The Scientific Method
• Experimental Design: Experimental Group, Control
Group, Variables, Sample Size, Repeated Trials
• Null Hypothesis: a statement or idea that can be
falsified, or proven wrong
• Inductive Reasoning: making general statements from
specific facts or examples.
• Deductive Reasoning: applying a general statement to
specific facts or situations