Environment
In agriculture what does the term intensity refer to?
Amount of food grown per unit of land
What is the primary factor contributing to the increase in salt concentration in Mono Lake?
Continual input of salts from tributaries combined with evaporation
What does a negative feedback loop typically do to a system variable?
Brings it back to a starting point
In population dynamics, what happens when a population exceeds its carrying capacity?
The population crashes
a)When the fluxes are unpredictable b)When the pool size is measurable c)When there is no net flux d)When the input exceeds the output e)None of the above
c)When there is no net flux
Over what period have global temperatures and atmospheric concentrations of carbon dioxide and methane fluctuated frequently?
Over the past 160,000 years
What was the primary cause of decline in bird population in Mono Lake?
Over-predation of flies and shrimp
What term do system analysts use to describe the balance of a system?
pool
Until the 1960's, the population of the human race was undergoing a pattern of ___
Exponential growth
What type of system is the Earth in respect to matter?
closed
Which type of system allows for the exchange of both matter and energy with other systems?
open
What was the outcome of the California Supreme Court's ruling regarding Mono Lake in 1983?
Implementation of new laws to better manage Mono Lake
A system is defined as being at steady state when ___
input equals output.
Approximately how many known species are there on Earth today?
1.8 million
What does Mean Residence Time (MRT) measure?
The average time a portion of a pool remains in a system
Which of the following is NOT considered an important area for understanding environmental systems?
a)Policy b)Economics c)Environmental advocacy and action d)Law e)Medicine
e)Medicine
What was the consequence of the increased salinity in Mono Lake?
Slower growth of algae population due to reduced nitrogen uptake
What is the mean residence time (MRT)?
The average amount of time a quantity of a variable stays in a given pool
What is the estimated "background" rate of mammal extinctions per 10,000 species per one hundred years?
2
Which human development stage is particularly sensitive to lead exposure?
fetuses and children
Since 1975, technological improvements have increased the fuel efficiency of most cars in the United States from an average of __ miles per gallon to more than __ miles per gallon by 2021.
a)Improvement in environmental quality b)decrease in overall extinction rates c)stability in ecosystems d)increase in biodiversity e)decrease in biodiversity
e)decrease in biodiversity
Which of the following describes what the formula for net flux represents?
The accumulation or depletion rate of material in a system
The United Nations projects that the world population will level off somewhere between how many billion people by the year 2150?
8 and 12 billion people
How does a positive feedback loop differ from a negative feedback loop?