NEW Sci Section 1 Flashcards
What is environmental science?
the study of the impacts of human activities on environmental systems
Environmental science is a tool used to develop ways to do what?
manage our impacts for a sustainable future
To study the impacts of humans, environmental science requires a ________________ approach.
interdisciplinary
What is an environment?
the sum total of all the conditions and factors that surround an organism
What is a local environment?
the area immediately surrounding an organism
Is the global environment simple?
No, it is extremely complicated
What is the global environment?
the sum of all aspects of Earth
Environmental science covers what disciplines?
biology, earth and atmospheric sciences, chemistry, physics, human population dynamics, and biological and natural resources
What type of discipline is environmental science?
a science-based discipline
What is a system?
a set of living and/or nonliving components connected in a way where changes in one part affect the others
Is Earth a system?
Yes
What might we use to determine if a person is healthy?
body temp, heart rate, respiration rate, and blood pressure
When something is wrong with a human body health indicator, what is it usually a signal of?
something is wrong with the human
What is an environmental indicator?
a measure that reflects the environmental health of a system
Is there a single indicator that assesses the whole planet?
No
The same environmental indicator can tell a different story depending on what?
where and/or when the measurement is taken
What are the 6 main categories of environmental indicators?
biological diversity, human population growth, food production, resource consumption, global temp/GHG levels, and pollution levels
What is biological diversity?
the diversity of genes, species, habitats, and ecosystems on Earth
The number of species on Earth, and whether that number is increasing or decreasing, can help us measure what?
the biological status of the planet
What is a species?
a group of organisms distinct from other groups in morphology, physiology, and biochemical properties
What does “GHGs” mean?
greenhouse gases
What is morphology?
body type
Species are a group of organisms distinct from other groups in _________, _________, and ___________ _____________.
morphology, physiology, biochemical properties
Individuals in a species must breed to do what?
produce viable offspring
How many known species are on Earth?
1.8 million
What is a “known” species?
a species that has been identified and catalogued
What is the actual number of species debated to be?
over 10x the number of known species
Why is the actual number of species higher than the known number?
because many have not been identified or cataloged yet
What species types in particular have not been identified or cataloged as much as there actually are?
microbial species
What percent of species that have ever lived on Earth are now extinct?
0.9990000000000001
What periods are used to determine background extinction rates before humans played a role?
the quiet periods
What are the quiet periods?
time periods with no massive environmental or biological upheaval
The quiet periods are times with no massive ___________ or ____________ upheaval.
environmental, biological
What are the background extinction rates?
2 mammal extinctions per 10,000 species per 100 years
Humans have accelerated background extinction rates to how many times higher?
100x higher
What is the biggest cause of extinction today?
loss and degradation of habitats
How many species are going extinct each year?
40000
The number of species on Earth is declining at a rate to rival what?
past mass extinction events
The Bengal tiger, snow leopard, and West Indian Manatee are examples of what species?
endangered species
What are endangered species?
species that will go extinct if death rates are not reversed
The loss of this species can cause a cascade of species going extinct.
keystone species
What are keystone species?
species that are of particular importance in an ecosystem and are relied on by many other species
What can we conclude if we use species diversity as an indicator of environmental quality
that the situation is getting worse and is not sustainable
In November 2022, the human population reached how many people?
8 billion
When did the human population reach 8 billion people?
November, 2022
How many babies are born each day?
378000
How many people die each day?
148000
How much does the human population increase each day?
230000
The human population gets almost a million new people every __ days.
4
Until which decade was the human population undergoing exponential growth?
the 1960s
Until the 1960s, the human population was growing ____________.
exponentially
For how long will the human population continue to increase?
50-100 years
The world population is projected to level off when/how much?
8-12 billion by 2150
The world population is projected to be how much by 2150?
8-12 billion
The world population is projected to be 8-12 billion people by when?
2150
What is a major question regarding the human population?
Can Earth sustain so many people?
The additional people on Earth will create what?
greater demand on Earth’s finite resources and more pollution and waste
What food group provides over half the calories eaten by humans?
food grains
Wheat corn, and rice are in what food group?
grains
How much of our calories are provided by food grains?
over 50%
What is worldwide grain production a result of?
quality of soil, climate conditions, land area, human labor, and water
Therefore, an increase or decrease in grain production is what?
an environmental indicator
What is intensity in the context of agriculture?
how much food is grown per unit of land
What is monoculture in agriculture?
when only one crop is planted
What is polyculture in agriculture?
when various crops are planted
Is monoculture typically high or low intensity?
high-intensity
Is polyculture typically high or low intensity?
low-intensity
What is yield in agriculture?
amount of crop produced per unit area of land
Are high-intensity practices in agriculture good for the local environment there?
No, it often leads to soil erosion, runoff of fertilizers, and an overall degradation of the land
What do high-intensity practices lead to?
soil erosion, runoff of fertilizers, buildup of pesticides, and an overall degradation of the land
As land becomes more degraded, what happens to its yield?
it decreases
What is sustainable use?
when consumption of resources allows for adequate supply for future generations
The rapid depletion of a resource indicates what about its sustainability?
It indicates the consumption of that resource is not sustainable.
More people generally means a _________ environmental impact.
greater
When all other factors are equal, a country where most people live in smaller houses will have a ________ environmental impact compared to one where most people live in large houses.
smaller
For some resources, a very _______ portion of the world’s population may be responsible for most of consumption.
small
What percent of people live in developed countries?
0.2
People who live in developed countries consume what percent of all meat and fish?
0.45
People who live in developed countries consume what percent of total energy?
0.58
People who live in developed countries consume what percent of all paper?
0.84
People who live in developed countries consume what percent of all automobiles and trucks?
0.87
The poorest 20% of people consume how much of resources?
5% or less
What are gases that trap heat around the Earth collectively known as?
greenhouse gases (GHGs)
What are 2 greenhouse gases that are present in the atmosphere due to natural processes and human activity?
Carbon dioxide and methane
What is the chemical formula for carbon dioxide?
CO2
What is the primary activity that produces CO2?
combustion of fossil fuels
For the past 130 years, what do global temperatures show?
some fluctuation, but an overall increase
How much CO2 is in our atmosphere? (parts per million)
420 parts per million
The increase in CO2 over the last __ centuries is anthropogenic.
2
The increase in CO2 over the last 2 centuries is ____________.
anthropogenic
What is the chemical symbol for lead?
Pb
Why is lead so useful?
because it is soft, malleable, and resists corrosion
What does malleable mean?
a material that can be shaped easily
Lead is malleable, and can be shaped with just a __________.
hammer
Why is lead bad?
because it is toxic to most plants and animals and impairs the human central nervous system
What part of the body does lead impair in humans?
the central nervous system
What is particularly sensitive to lead?
developing brains, found in children and fetuses
What is the amount of lead in an environmental system an indicator of?
the amount of pollution that has been introduced into the environment
What is the amount of lead in an environmental system an indirect indicator of?
the amount of harm that may have occurred from human manipulation of the environment
When did lead mining start?
5,000 years ago
How has the amount of lead mining changed from 5,000 years ago to now?
it has increased
What caused greater releases of lead into the atmosphere?
changes in refining techniques during the Industrial Revolution
What was lead an additive to?
gasoline
Why was lead added to gasoline?
to improve engine performance
Much of lead production and emissions in the 20th century were a result of what?
leaded gasoline
What did clean air legislation require?
new cars in the U.S. use gasoline without lead
When did clean air legislation, which required unleaded gasoline to be used in new cars, begin?
1975
What is primarily responsible for decreases in lead emissions?
the switch to unleaded gasoline
If we use global lead emissions as an environmental indicator, what can we conclude?
that the situation is improving
Is there lead in unleaded gasoline?
Yes, as oil naturally contains lead
What fossil fuels contain lead?
coal and oil
Lead was also a major ingredient in __________.
paint
When did lead stop being used in paint as much?
1960
Many houses built before 1960 used this type of paint.
peeling paint
What does peeling paint made before 1960 have high concentrations of?
lead
Paint made before 1960 can have lead concentrations of how much?
up to 50%
When peeling paint peels, what can happen?
the lead in the paint can be ingested by young
What is the major source of lead contamination in the US today?
our drinking water
What causes lead to get into our drinking water?
lead pipes and other plumbing that corrodes
What type of water corrodes lead faster?
highly acidic water
Where are lead pipes and plumbing common?
low-income communities
Does a simple experiment conducted by a college student follow the same principles as a large, million-dollar experiment?
Yes
Scientific information has been collected, analyzed, and synthesized through what process?
the scientific method
What is the 1st step of the scientific method?
Observe, and ask questions about those observations
What is the 2nd step of the scientific method?
Generate a hypothesis that could answer a question
A hypothesis must be _________ and __________.
testable and falsifiable
The researcher must have a hypothesis with what quality?
a hypothesis that can be proven correct or incorrect
What is the 3rd step of the scientific method?
Make a preliminary determination of whether the hypothesis is true or false using existing information
What is the 4th step of the scientific method?
Test the hypothesis with an experiment
What are the 2 main types of experiments?
manipulation and observational experiments
What is the 5th step of the scientific method?
Accept, revise, or reject the hypothesis and reconcile any differences between the predictions and results
What is the 6th step of the scientific method?
Report findings to others
What is the 7th step of the scientific method?
Replicate the experiment and notice if the results hold true multiple times
When a given hypothesis is tested and accepted by many scientists, what may it become?
a scientific finding
If a hypothesis is widely accepted, what does it become?
a theory
What is a theory?
a widely accepted hypothesis
If a theory is widely accepted and applies universally without exceptions, what does it become?
a universal law
What is a universal law?
a theory that is widely accepted and applies universally without exceptions
What is the First Law of Thermodynamics an example of?
a universal law
What does the First Law of Thermodynamics state?
energy cannot be created or destroyed, it simply changes form
What scientific findings are considered definitely proven?
None
What are scientific laws considered to be?
not disproven, meaning it is not proven, but not disproven either
Why are scientific laws not considered definitely proven?
because new can potentially disprove them
What is an observational experiment?
when the researcher observes the system without any interference
A biologist observing interactions between wolves and moose is considered what type of experiment?
an observational experiment
What is a manipulation experiment?
when the researcher changes an aspect to compare with the unchanged aspect
What is the aspect that is changed in a manipulation experiment is called?
the experimental variable
What is an experimental variable?
the aspect of the manipulation experiment that is changed
The elements in a manipulation experiment are divided into what 2 groups?
the experimental group and the control group
What group in a manipulation experiment is being manipulated?
the experimental group
What group in a manipulation experiment is left undisturbed for comparison?
the control group
What is the control group in a manipulation experiment?
the group that is left undisturbed and being compared to
How many variables should be changed in a manipulation experiment?
1
What is sample size?
the number of individuals tested or samples collected
How many acres are in a hectare?
2.47 acres in 1 hectare
In the scientific process, when can we trust the observed hypothesis is correct and significant?
when it has been repeated over and over again with little to no variation
What must the investigators have in order to conduct a scientifically sound study?
a large enough sample size and a distinct difference between the experimental and control groups
What type of relationship must occur between the manipulation and its result?
a cause-effect relationship
“A butterfly stirring the air in Beijing can affect weather patterns in New York a month later.” This statement is a poetic way of describing what?
the interconnectedness of Earth’s systems
The study of the environment is the study of its _________.
systems
In practice, what are systems defined by?
the person looking at them
What is the largest system studied by environmental scientists?
the global system, Earth
What are the interactions of systems and components within systems known as?
systems dynamics
What are systems dynamics?
the interactions of systems and components within systems
Environmental systems involve the exchange of _________ and __________.
matter, energy
What is one of the most important materials involved in environmental systems?
water
What source of energy do all environmental systems ultimately depend on?
the Sun
What can systems be? (2 states)
open or closed
What is an open system?
one where the exchange of matter or energy does occur
What is a closed system?
one where the exchange of matter or energy doesn’t occur
Is the Earth system open or closed with respect to energy?
Open
How is the Earth system open with respect to energy?
solar energy enters and heat energy leaves
Is the Earth system open or closed with respect to matter?
Closed
How is the Earth system closed with respect to matter?
nothing leaves or enters except for the occasional meteorite or space shuttle
Is the ocean system open or closed with respect to matter and energy?
Open
What are the most important areas of human, non-scientific endeavor that are important to our understanding of the environment?
Economics, Social structures and institutions (like governments), Law, Policy, and Environmental advocacy and action
People who examine systems often conduct a __________ ____________.
system analysis
What do system analyses determine?
what goes in, what comes out, and what has changed within a system
The analysis one might do on their checking account is similar to what?
a system analysis
In a checking account, what is the sum of money you start with called?
balance
What do system analysts call the starting amount of something in a system?
the pool
What do system analysts call things added to a system?
inputs
What do system analysts call things removed from a system?
outputs
What is a change in pool called?
a flux
What is a flux?
a change in the pool
What is a flow per unit of time?
a flux rate
What is a flux rate?
a flow per unit of time
What is mass balance analysis?
accounting of the inputs and outputs to determine fluxes in a system
Why is a mass balance analysis called this?
because it was designed to be done with materials that have mass
What is the formula for net flux?
Net Flux = Inputs - Outputs
What is the most important part of conducting a system analysis?
finding out if your system is in steady state
What is the first step in determining whether a system is in steady state?
determining the size of the pool
How can we find the size of a pool?
directly or estimation
Would we find the size of a bucket of water directly or through estimation?
directly
Would we find the size of an immobile pool directly or through estimation?
through estimation
Would we find the size of a flock of birds directly or through estimation?
through estimation
What does net flux equal in a system in steady state?
Net Flux = 0
Why would a community ban watering lawns and washing cars during a dry summer?
because their water reserves aren’t in steady state
If a resource is decreasing in size, is it being used sustainably?
No
Can one part of a system be in steady state while the other isn’t?
Yes
What formula can we use to calculate accumulation and depletion rates?
the Net Flux formula, Net Flux = Inputs - Outputs
What are adjustments made by a system in response to behavior or events?
feedbacks
What are feedbacks?
adjustments made by a system in response to behavior or events
What type of feedback loop is balancing a checkbook?
a negative feedback loop
What happens in a negative feedback loop?
the system variable is brought back, or closer to, the start point
A gambler continuously betting away his life savings is an example of which feedback loop?
a positive feedback loop
Is Earth’s heating system a positive or negative feedback loop?
We don’t know for sure
What is the balance in many environmental systems dependent on?
the smooth operation of feedback loops
What happens when the negative feedback loop breaks down?
the variable gets sent away from the set point
What is the set point in an environmental system?
the stable value for the parameter under examination
What is exceeding the set point of a system known as?
overshoot
When a population’s birth rate is high, can factors controlling population growth compensate fast enough?
No
What is the amount of individuals that can be supported by an environment?
carrying capacity
What is the result of a population overshoot?
a dramatic population crash, usually from disease or starvation
What is a population?
a group of individuals in a single species
What inputs control a population size?
births and immigration
What outputs control a population size?
deaths and emigration
What is immigration?
individuals entering a population
What is emigration?
individuals leaving a population
What is the formula for net population change?
Net Population Change = Inputs - Outputs
For most populations, what factors outweigh the others in controlling population size?
births and deaths usually outnumber immigration and emigration
Is it easy to estimate birth and death rates?
Yes
What about determining population change is more difficult?
determining how the flows for deaths and births are regulated
What does abiotic mean?
nonliving
As a deer population increases in size, how will the amount of available food change?
it will be less
How does less food affect birth rates?
less food means less energy for females to put into reproduction, lowering birth rates
In more complex systems, what may a population be regulated by?
the population of another
In most predator-prey systems, the amount of predation __________ as the number of prey increases.
increases
Why does the amount of predation usually increase as the number of prey increases?
because it is easier to find them and hunt
How is an increased rabbit population a negative feedback loop?
because its predators will simply bring its population down again by increasing predatioin
