BIOL 350 FINAL EXAM -exam elaborations with 100% verified
answer/solutions- Excel & Succeed – Already Graded A+
1) 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. - (ANSWER)Problems of input:
-Deforestation; clearing forests for agriculture, urban expansion, mining, over-harvesting for timber and
paper production
-increased frequency of fire, drought, insect outbreaks
-clearing forests out faster than we can replace them
-world forest area shrunk by 80% per capita in past century
Value:
-"earth's lungs"; source of oxygen
-Earth's major source of water circulation; about 50% of the water that ends up in the clouds for rain has
been transpired by forests
-forests build and protect top soil; without forests we lose soil and minerals through erosion
-major carbon sinks; capture, store, and decrease greenhouse carbon dioxide levels (about 25% of
carbon emitted by burning fossil fuels each year are absorbed by forests)
-home to Earth's treasury of biodiversity
(2) World food production now appears to have peaked and prices are rising. Describe the main reasons
for this crisis that we discussed in BIOL350. - (ANSWER)Today's food shortages result from 4 critical long-
term trends:
1) Rapid pop'n growth
-leads to over-plowing and over-grazing resulting in a loss of top soil
-increased demand for energy therefore increasing energy from fossil fuels which contributes to global
warming
-higher demand for food...causing food shortages
2)Loss of top soil
-because of deforestation, global warming, over-plowing...etc
3)Spreading water shortages
4)Rising temperatures and Global warming
,BIOL 350 FINAL EXAM -exam elaborations with 100% verified
answer/solutions- Excel & Succeed – Already Graded A+
-leads to rising sea level causing coastal flooding, which leads to loss of top soil
-higher temps also reduce crop yield
OTHER REASONS:
-arable land has peaked
-lost irrigation water from melting/dried up glaciers resulting from global warming
-rising energy prices
-more land being used to grow bio-fuels instead of crops
-falling pollinator (bee) pop'ns from pesticide use and pollution
-over exploitation of fish
(3) 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'. -
(ANSWER)problems of input:
-problem of supply and demand
-oil discoveries peaked in the 60s and since the 80s we have used more oil yearly than we are discovering
-most things that we use require oil/natural gas to make (includes everything plastic)
-rely on fossil fuels for transportation
-since the Great acceleration 5x more energy use (especially fossil fuels)
-turn to renewable resources like solar and wind energy but forget that a lot of these alternate solutions
depend on petro chemicals/fossil fuels to keep them running; not durable, reliable, or completely safe
-2x more oil consumption in last 4 decades
-fossil fuels=non-renewable=definite supply
-contributes to global warming/climate change
4) 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 'input' -
(ANSWER)soil is one of the most precious and threatened resources:
-arable land is disappearing...top soil is vital for maintaining the world's food supply
,BIOL 350 FINAL EXAM -exam elaborations with 100% verified
answer/solutions- Excel & Succeed – Already Graded A+
-it takes centuries to generate an inch of top soil even in a healthy ecosystem so essentially it is a non-
renewable resource
-soil degradation is especially high in dry lands due to salination from irrigation
-losing it from water erosion, wind, glacier melting (flooding) , deforestation
-loss of biodiversity from pesticide use; less biodiversity= more susceptible to disease
MAIN PROBLEM OF OUTPUT= decreased capacity for food production
(5) 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. - (ANSWER)Global
conveyer belt= a constantly moving system of deep ocean circulation driven by temp/salinity; warm less
salinated water from gulf stream travels upward towards Europe in Atlantic and the wind over this
current picks up heat to warm Europe...this causes evaporation making the water more salty which
makes the water colder b/c it's more dense and sinks...downdraft of heavy cold water generates south
going stream
How is it disrupted?
-warming of arctic ice/Greenland ice sheet making the North Atlantic less salty therefore surface
currents aren't as warm, making Europe colder
Consequences:
-colder Europe= shorter growing season
-crop loss/less food production
(6) Several forecasters have predicted that even if we completely stop all fossil fuel burning tomorrow, it
is too late to stop climate change. Describe the main reasons why this may be so. - (ANSWER)-it will take
an 80% decrease in carbon dioxide emission by 2050 to stabilize atmospheric gas concentration
-feedback loops not in our favor; 1) increased levels of water vapour in the atmosphere traps heat, leads
to more evaporation of water vapour increasing the amount of trapped heat, 2) loss of snow from global
warming exposes more land area which is less reflective then snow that the sun rays hit therefore
absorbing more heat because not as much snow covered surface to reflect,3) melting of permafrost
boreal regions released greenhouse gas methane into the atmosphere
-rising CO2 levels lead to ocean acidity which worsens global warming
, BIOL 350 FINAL EXAM -exam elaborations with 100% verified
answer/solutions- Excel & Succeed – Already Graded A+
-likely not possible to come up with an oil/gas alternative in time to; continue providing the energy need
to keep civilization running as we know it, further stop climate change
-climate change due to increases in carbon dioxide concentration is largely irreversible for 1000 years
after emissions stop
-we have already "kick-started" an irreversible self-escalating series of natural causes effecting global
warming
(7) Many experts today believe that bio-fuel production causes more problems than it solves. Describe
the main reasoning behind this view. - (ANSWER)bio-fuel production causes loss of tropical forests and
other natural habitats, depletes oil, accelerates climate changes, exacerbates world hunger
-releases nitrous oxide
-countries fail to plan for cleaner energy
-these approaches do not help rising sea levels
-to grow biofuel crops, large scale forest burnings are needed to clear area
-farming biofuels releases nitrous oxide (climate change)
-biofuel from algae could create 4x the greenhouse gas
(8) 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 'population' as a problem of 'output'. -
(ANSWER)-population is estimated to reach 9 billion by 2050
-there are at least 1 billion people today that are severely malnourished/starving
-world population growth rate peaked in 1970; now it's slightly decreasing in developed but increasing in
underdeveloped countries
-high growth rates in developing countries and higher fertility rates in poorer countries
-urban growth to mega-cities (cities of 10 million or more) ; how will they survive the effects of climate
change? increasing resource competition? decreasing supplies/oil?
-there are now fewer farmers to feed the growing pop'n
-MALTHUSIAN DILEMMA; pop'n growth will outpace agricultural production ... too many people, not
enough food
-increased risk for disease outbreaks with larger pop'n
answer/solutions- Excel & Succeed – Already Graded A+
1) 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. - (ANSWER)Problems of input:
-Deforestation; clearing forests for agriculture, urban expansion, mining, over-harvesting for timber and
paper production
-increased frequency of fire, drought, insect outbreaks
-clearing forests out faster than we can replace them
-world forest area shrunk by 80% per capita in past century
Value:
-"earth's lungs"; source of oxygen
-Earth's major source of water circulation; about 50% of the water that ends up in the clouds for rain has
been transpired by forests
-forests build and protect top soil; without forests we lose soil and minerals through erosion
-major carbon sinks; capture, store, and decrease greenhouse carbon dioxide levels (about 25% of
carbon emitted by burning fossil fuels each year are absorbed by forests)
-home to Earth's treasury of biodiversity
(2) World food production now appears to have peaked and prices are rising. Describe the main reasons
for this crisis that we discussed in BIOL350. - (ANSWER)Today's food shortages result from 4 critical long-
term trends:
1) Rapid pop'n growth
-leads to over-plowing and over-grazing resulting in a loss of top soil
-increased demand for energy therefore increasing energy from fossil fuels which contributes to global
warming
-higher demand for food...causing food shortages
2)Loss of top soil
-because of deforestation, global warming, over-plowing...etc
3)Spreading water shortages
4)Rising temperatures and Global warming
,BIOL 350 FINAL EXAM -exam elaborations with 100% verified
answer/solutions- Excel & Succeed – Already Graded A+
-leads to rising sea level causing coastal flooding, which leads to loss of top soil
-higher temps also reduce crop yield
OTHER REASONS:
-arable land has peaked
-lost irrigation water from melting/dried up glaciers resulting from global warming
-rising energy prices
-more land being used to grow bio-fuels instead of crops
-falling pollinator (bee) pop'ns from pesticide use and pollution
-over exploitation of fish
(3) 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'. -
(ANSWER)problems of input:
-problem of supply and demand
-oil discoveries peaked in the 60s and since the 80s we have used more oil yearly than we are discovering
-most things that we use require oil/natural gas to make (includes everything plastic)
-rely on fossil fuels for transportation
-since the Great acceleration 5x more energy use (especially fossil fuels)
-turn to renewable resources like solar and wind energy but forget that a lot of these alternate solutions
depend on petro chemicals/fossil fuels to keep them running; not durable, reliable, or completely safe
-2x more oil consumption in last 4 decades
-fossil fuels=non-renewable=definite supply
-contributes to global warming/climate change
4) 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 'input' -
(ANSWER)soil is one of the most precious and threatened resources:
-arable land is disappearing...top soil is vital for maintaining the world's food supply
,BIOL 350 FINAL EXAM -exam elaborations with 100% verified
answer/solutions- Excel & Succeed – Already Graded A+
-it takes centuries to generate an inch of top soil even in a healthy ecosystem so essentially it is a non-
renewable resource
-soil degradation is especially high in dry lands due to salination from irrigation
-losing it from water erosion, wind, glacier melting (flooding) , deforestation
-loss of biodiversity from pesticide use; less biodiversity= more susceptible to disease
MAIN PROBLEM OF OUTPUT= decreased capacity for food production
(5) 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. - (ANSWER)Global
conveyer belt= a constantly moving system of deep ocean circulation driven by temp/salinity; warm less
salinated water from gulf stream travels upward towards Europe in Atlantic and the wind over this
current picks up heat to warm Europe...this causes evaporation making the water more salty which
makes the water colder b/c it's more dense and sinks...downdraft of heavy cold water generates south
going stream
How is it disrupted?
-warming of arctic ice/Greenland ice sheet making the North Atlantic less salty therefore surface
currents aren't as warm, making Europe colder
Consequences:
-colder Europe= shorter growing season
-crop loss/less food production
(6) Several forecasters have predicted that even if we completely stop all fossil fuel burning tomorrow, it
is too late to stop climate change. Describe the main reasons why this may be so. - (ANSWER)-it will take
an 80% decrease in carbon dioxide emission by 2050 to stabilize atmospheric gas concentration
-feedback loops not in our favor; 1) increased levels of water vapour in the atmosphere traps heat, leads
to more evaporation of water vapour increasing the amount of trapped heat, 2) loss of snow from global
warming exposes more land area which is less reflective then snow that the sun rays hit therefore
absorbing more heat because not as much snow covered surface to reflect,3) melting of permafrost
boreal regions released greenhouse gas methane into the atmosphere
-rising CO2 levels lead to ocean acidity which worsens global warming
, BIOL 350 FINAL EXAM -exam elaborations with 100% verified
answer/solutions- Excel & Succeed – Already Graded A+
-likely not possible to come up with an oil/gas alternative in time to; continue providing the energy need
to keep civilization running as we know it, further stop climate change
-climate change due to increases in carbon dioxide concentration is largely irreversible for 1000 years
after emissions stop
-we have already "kick-started" an irreversible self-escalating series of natural causes effecting global
warming
(7) Many experts today believe that bio-fuel production causes more problems than it solves. Describe
the main reasoning behind this view. - (ANSWER)bio-fuel production causes loss of tropical forests and
other natural habitats, depletes oil, accelerates climate changes, exacerbates world hunger
-releases nitrous oxide
-countries fail to plan for cleaner energy
-these approaches do not help rising sea levels
-to grow biofuel crops, large scale forest burnings are needed to clear area
-farming biofuels releases nitrous oxide (climate change)
-biofuel from algae could create 4x the greenhouse gas
(8) 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 'population' as a problem of 'output'. -
(ANSWER)-population is estimated to reach 9 billion by 2050
-there are at least 1 billion people today that are severely malnourished/starving
-world population growth rate peaked in 1970; now it's slightly decreasing in developed but increasing in
underdeveloped countries
-high growth rates in developing countries and higher fertility rates in poorer countries
-urban growth to mega-cities (cities of 10 million or more) ; how will they survive the effects of climate
change? increasing resource competition? decreasing supplies/oil?
-there are now fewer farmers to feed the growing pop'n
-MALTHUSIAN DILEMMA; pop'n growth will outpace agricultural production ... too many people, not
enough food
-increased risk for disease outbreaks with larger pop'n
