BIOL 350 Exam questions and
answers graded A+
The current state of civilization can be described in terms of problems of 'input' or problems of
'output'. Describe the main current concerns associated with 'forests' as a problem of 'input',
and describe the main reasons why forests have important value in terms of providing
ecosystem services for humans. - correct answer ✔✔ The Current State of Civilizations:
Problems of Input - Forests
• Forests provide essential services
o Provide fuel, fiber and lumber
o Are the earth's lungs (w/ algae in ocean) act as a major source of oxygen for the atmosphere
o Are the earth's source of water circulation (50% of water in clouds has been transpired by
forests)
♣ Remove forests = produce desert
o Build and protect top soil
♣ Remove forests = loss soil and minerals by erosion
o Act as a major carbon sink, capturing and decreasing greenhouse carbon dioxide levels
o Home to the earth's treasury of biodiversity
• Timber production has increased dramatically during acceleration
o Household and sanitary paper, writing paper, cardboard and packaging
World food production now appears to have peaked and prices are sky-rocketing. Describe the
main reasons for this crisis. - correct answer ✔✔ The Current State of Civilizations: Problems of
Input - Food
• The absolute number and % of chronically undernourished people in the world are climbing
while the world's backup food supply is declining
• Populations are expanding fastest in regions where it is most difficult to grow food
,o Africa/Middle East - driest regions but fastest growing in population
• Key factors in food shortages:
o Loss of topsoil
o Spreading water shortages
o Rising temperatures
o Escalating population growth
• Food production has peaked and prices are rising
• Other reasons for food shortage include:
o Arable land has peaked
o Lost irrigation water from melting glaciers resulting from global warming
o Rising oil prices
o More land used to grow biofuels instead of crops
o Pollinator (bee) populations have been failing due to pesticide use and pollution
o Rising prosperity of the world's two most populous nations, China and India
• The warming world of climate change poses a threat to our food supply
o Higher temperatures, reduced rainfall = reduced agricultural productivity
• Another limitation is the result of emphasis on only a few high-yielding and profitable varieties
of fruits and vegetables
o Seed stock for over 90% of varieties available in 1903 have been abandoned, that genetic
diversity is lost forever
• Much of the world depends on fish as a staple in diet
o Marine fishstocks are now fully exploited or decimated worldwide
• We have reached a global food crisis and food security has become one of the most pressing
issues of our time
o Efforts to solve it can escalate the problem
o Growing more food feeds the hungry—for now—but it also creates more mouths that need
feeding
,The current state of civilization can be described in terms of problems of 'input' or problems of
'output'. Describe the main current concerns associated with 'fossil fuels' as a problem of
'input'. - correct answer ✔✔ • The great acceleration is a direct product of the extraction and
use of energy, mainly from fossil fuels
o World reserves of fossil fuels vary by region
• Oil and natural gas are prized fuels because of high energy density
o Oil fields don't last forever, they all peak
o At some point, the energy required to extract a barrel of oil exceeds the energy contained in a
barrel of oil so that pumps shut down
o Oil production is now starting to peak
• Since 1980, we use more oil than we have discovered
o 25 years of oil are left at current exploitation levels, so we're starting to be "tapped out"
• The arrival of peak oil may have benefits for climate change
• Oil will become scarce, expensive but we won't run out
• As oil runs out, there is concern that society will switch to the most abundant fuel, which is
coal
o Coal emits 25-50% more carbon dioxide
• The other fossil fuel alternative is natural gas, available in abundance using hydraulic
fracturing
o Has risks of leaks of methane which is a more powerful greenhouse gas than carbon dioxide
• The demand for fossil fuels is likely to keep growing
• Nuclear power is an unlikely rescue due to serious limitations and safety concerns
• Renewables show great promise for electricity generation
o Hydro, wind, solar will exceed gas and be twice more than nuclear
o Presently it seems doubtful that renewables will replace the energy received from gasoline
(dense/portable)
• Petro-chemicals from oil and natural gas are used as ingredients in most things that we use
including everything plastic—including in solar panels and wind turbines
, The current state of civilization can be described in terms of problems of 'input' or problems of
'output'. Describe the main current concerns associated with 'soil loss' as a problem of 'output'.
- correct answer ✔✔ The Current State of Civilizations: Problems of Input - Soil
• Successful agriculture requires healthy soil
o In a natural habitat, soil is healthy and stable because organisms take and put resources into
the soil
o In an agricultural crop, the soil becomes degraded over time (volume loss/nutrient loss b/c
erosion from wind and water)
o Can remedy this loss with fertilizers but this causes more volume/nutrient loss and pollution
of water systems
o Since it is a monoculture, pesticides are added leading to MORE volume/nutrient loss, water
pollution and lost biodiversity (esp. for organisms living in the soil)
o Irrigation also worsens these same things (and causes salination over time)
• Fertilizers, pesticides are produced from oils and oil pumps for irrigation but without oil?
o Modern agriculture cannot continue without oil
• The loss of arable land places a critical limitation on agricultural activity
o Soil degradation is high in drylands because of salination from irrigation
• Africa, Middle East and Asia are most at risk for future soil degradation mainly because of
combinations of dry climate (degradation from irrigation and salination) but also because of the
long history of agriculture and high population densities
• North America and Europe have highest pesticide use
• We have now passed the peak of global abundance of healthy topsoil
Forecasters worry that climate change may disrupt the so-called 'global ocean conveyer'.
Describe what this is, how it might be disrupted, and what the main consequences would be. -
correct answer ✔✔ Global warming is starting to disrupt the global ocean conveyor
• Ocean currents are driven by an important transition that takes place in the North Atlantic
• As the gulf stream pushes N, wind blowing across the Atlantic causes evaporation, leading to
saltier water and picks up heat from the water thus warming Europe
answers graded A+
The current state of civilization can be described in terms of problems of 'input' or problems of
'output'. Describe the main current concerns associated with 'forests' as a problem of 'input',
and describe the main reasons why forests have important value in terms of providing
ecosystem services for humans. - correct answer ✔✔ The Current State of Civilizations:
Problems of Input - Forests
• Forests provide essential services
o Provide fuel, fiber and lumber
o Are the earth's lungs (w/ algae in ocean) act as a major source of oxygen for the atmosphere
o Are the earth's source of water circulation (50% of water in clouds has been transpired by
forests)
♣ Remove forests = produce desert
o Build and protect top soil
♣ Remove forests = loss soil and minerals by erosion
o Act as a major carbon sink, capturing and decreasing greenhouse carbon dioxide levels
o Home to the earth's treasury of biodiversity
• Timber production has increased dramatically during acceleration
o Household and sanitary paper, writing paper, cardboard and packaging
World food production now appears to have peaked and prices are sky-rocketing. Describe the
main reasons for this crisis. - correct answer ✔✔ The Current State of Civilizations: Problems of
Input - Food
• The absolute number and % of chronically undernourished people in the world are climbing
while the world's backup food supply is declining
• Populations are expanding fastest in regions where it is most difficult to grow food
,o Africa/Middle East - driest regions but fastest growing in population
• Key factors in food shortages:
o Loss of topsoil
o Spreading water shortages
o Rising temperatures
o Escalating population growth
• Food production has peaked and prices are rising
• Other reasons for food shortage include:
o Arable land has peaked
o Lost irrigation water from melting glaciers resulting from global warming
o Rising oil prices
o More land used to grow biofuels instead of crops
o Pollinator (bee) populations have been failing due to pesticide use and pollution
o Rising prosperity of the world's two most populous nations, China and India
• The warming world of climate change poses a threat to our food supply
o Higher temperatures, reduced rainfall = reduced agricultural productivity
• Another limitation is the result of emphasis on only a few high-yielding and profitable varieties
of fruits and vegetables
o Seed stock for over 90% of varieties available in 1903 have been abandoned, that genetic
diversity is lost forever
• Much of the world depends on fish as a staple in diet
o Marine fishstocks are now fully exploited or decimated worldwide
• We have reached a global food crisis and food security has become one of the most pressing
issues of our time
o Efforts to solve it can escalate the problem
o Growing more food feeds the hungry—for now—but it also creates more mouths that need
feeding
,The current state of civilization can be described in terms of problems of 'input' or problems of
'output'. Describe the main current concerns associated with 'fossil fuels' as a problem of
'input'. - correct answer ✔✔ • The great acceleration is a direct product of the extraction and
use of energy, mainly from fossil fuels
o World reserves of fossil fuels vary by region
• Oil and natural gas are prized fuels because of high energy density
o Oil fields don't last forever, they all peak
o At some point, the energy required to extract a barrel of oil exceeds the energy contained in a
barrel of oil so that pumps shut down
o Oil production is now starting to peak
• Since 1980, we use more oil than we have discovered
o 25 years of oil are left at current exploitation levels, so we're starting to be "tapped out"
• The arrival of peak oil may have benefits for climate change
• Oil will become scarce, expensive but we won't run out
• As oil runs out, there is concern that society will switch to the most abundant fuel, which is
coal
o Coal emits 25-50% more carbon dioxide
• The other fossil fuel alternative is natural gas, available in abundance using hydraulic
fracturing
o Has risks of leaks of methane which is a more powerful greenhouse gas than carbon dioxide
• The demand for fossil fuels is likely to keep growing
• Nuclear power is an unlikely rescue due to serious limitations and safety concerns
• Renewables show great promise for electricity generation
o Hydro, wind, solar will exceed gas and be twice more than nuclear
o Presently it seems doubtful that renewables will replace the energy received from gasoline
(dense/portable)
• Petro-chemicals from oil and natural gas are used as ingredients in most things that we use
including everything plastic—including in solar panels and wind turbines
, The current state of civilization can be described in terms of problems of 'input' or problems of
'output'. Describe the main current concerns associated with 'soil loss' as a problem of 'output'.
- correct answer ✔✔ The Current State of Civilizations: Problems of Input - Soil
• Successful agriculture requires healthy soil
o In a natural habitat, soil is healthy and stable because organisms take and put resources into
the soil
o In an agricultural crop, the soil becomes degraded over time (volume loss/nutrient loss b/c
erosion from wind and water)
o Can remedy this loss with fertilizers but this causes more volume/nutrient loss and pollution
of water systems
o Since it is a monoculture, pesticides are added leading to MORE volume/nutrient loss, water
pollution and lost biodiversity (esp. for organisms living in the soil)
o Irrigation also worsens these same things (and causes salination over time)
• Fertilizers, pesticides are produced from oils and oil pumps for irrigation but without oil?
o Modern agriculture cannot continue without oil
• The loss of arable land places a critical limitation on agricultural activity
o Soil degradation is high in drylands because of salination from irrigation
• Africa, Middle East and Asia are most at risk for future soil degradation mainly because of
combinations of dry climate (degradation from irrigation and salination) but also because of the
long history of agriculture and high population densities
• North America and Europe have highest pesticide use
• We have now passed the peak of global abundance of healthy topsoil
Forecasters worry that climate change may disrupt the so-called 'global ocean conveyer'.
Describe what this is, how it might be disrupted, and what the main consequences would be. -
correct answer ✔✔ Global warming is starting to disrupt the global ocean conveyor
• Ocean currents are driven by an important transition that takes place in the North Atlantic
• As the gulf stream pushes N, wind blowing across the Atlantic causes evaporation, leading to
saltier water and picks up heat from the water thus warming Europe
