Deck 12: Global Biogeochemical Cycles and Their Alteration by Humans

Question 1

The rate of phosphorous flow through the global environment is three times faster now than before the industrial and agricultural revolutions.The main problem with this accelerated cycle is that?

A) It results in acidification of the oceans
B) It causes drastica alteration of ocean currents
C) It causes eutrophication of freshwater lakes
D) It initially slows the growth of freshwater vegetation

Answer 1

C

Question 2

Prior to the Industrial Revolution,what was the level of atmospheric carbon dioxide,and what is the current level?

A) Below 265 ppm pre Industrial Revolution; 200 ppm in 2014
B) Below 200 ppm pre Industrial Revolution; 4,000 ppm in 2014
C) Below 265 pre Industrial Revolution; 398 ppm in 2014
D) Below 200 ppm pre Industrial Revolution; 30,000 ppm in 2014

Answer 2

C

Question 3

What action by humans has most accelerated the phosphorus cycle?

A) Using cleaning agents that contain phosphorus compounds
B) Clear cutting forests
C) Mining phosphorus for fertilizer
D) Ocean acidification that has increased the proportion of phosphorus bound to sediments

Answer 3

C

Question 4

The sulfur cycle is important for many reasons,including ecological processes.Sulfate is critical to the decomposition process.Why else is the sulfur cycle so critical to life on Earth?

A) There are no other reasons
B) Because sulfate is an essential component of several amino acids
C) Because sulfur is always limiting to primary productivity
D) Sulfur gases are essential to global atmosphere

Question 5

The IPCC shows what levels of carbon dioxide were in the Earth's atmosphere for the last 10,000 years.How are they able to do this?

A) They extrapolate data from recent measurements
B) They use tree rings
C) They use bubbles of atmospheric gas trapped in ice samples
D) The data are from a model and not actual data

Question 6

Which researcher(s)proposed the idea that there are ten planetary life-sustaining biophysical systems that are essential for life on Earth?

A) The IPCC
B) Svante Arrhenius
C) Charles Keeling
D) Rockstrom et al.

Question 7

Which of the following is a reason why the rate of phosphorus flow through the global environment is approximately three times greater than preindustrial and pre-agricultural revolutions?

A) Phosphorus from rock beds
B) Decaying plant matter
C) Deforestation
D) Phosphorus cleaning agents and fertilizer usage

Question 8

Using Figure 12.3,which of the following statements is accurate regarding the concentration of Earth's atmospheric carbon dioxide through time?

A) Over the last 200 years (1800 to 2000), the Earth's carbon dioxide levels doubled
B) Over the last 10,000 years carbon dioxide levels on Earth have doubled
C) Over the last 200 years (1800 to 2000), the Earth's carbon dioxide levels have increased greater than 100 ppm.
D) All of the above

Question 9

While some carbon accumulates in the atmosphere the rest is taken up by

A) Oceans
B) Oceans and terrestrial systems
C) Terrestrial systems
D) Frozen tundra

Question 10

Sulfur pollution was primarily responsible for what environmental problem in North America and Europe?

A) Eutrophication
B) Desertification
C) Desalinization
D) Acid rain

Question 11

What most explains the flux of carbon dioxide into the atmosphere from 1960 to present?

A) Deforestation
B) Livestock
C) Fossil fuel combustion
D) Changes to the carbon, nitrogen, and phosphorus cycles

Question 12

You are researching a biotic process that controls the chemistry of the environment and your colleague is studying how the structure and function of that same ecosystem is controlled by geochemical processes.What field of science are you both working in?

A) Community ecology
B) Population biology
C) Biogeochemistry
D) Molecular ecology

Question 13

According to the Rockstrom paper,which of Earth's critical "life-support" systems has been perturbed most beyond Rockstrom's "safe" level?

A) Climate change
B) Biodiversity
C) Phosphorous cycle
D) Ocean acidification

Question 14

How many degrees Celsius was the global average temperature in 2011 above the long-term average from the early 20th century?

A) 0.7 degrees Celsius
B) 7.0 degrees Celsius
C) 1.7 degrees Celsius
D) 0.0 degrees Celsius

Question 15

In Figure 12.5,prior to 1850,the global flux of carbon dioxide to the atmosphere due to fossil fuel emissions was close to zero.However,in the late 19th century,an increase can be observed.From 1900 to 2010,what has occurred with the global flux of carbon dioxide due to fossil fuel emissions?

A) It has increased from approximately 2 Pg of carbon per year to nearly 5 Pg of carbon per year
B) It has decreased from approximately 2 Pg of carbon per year to nearly -10 Pg of carbon per year
C) It has risen 10 fold
D) It has increased from approximately 2 Pg of carbon per year to nearly 10 Pg of carbon per year

Question 16

In the 1960s,sulfur pollution in North America and Europe was a major cause of acid rain.Though sulfur pollution has been reduced due to regulation,pollution due to which compound appears to contribute to acid rain formation today?

A) Molybdenum pollution
B) Nitrogen pollution
C) Sulfate pollution
D) All of the above

Question 17

In recent years (1993-2013)the global rate of increase in carbon dioxide concentrations has leveled off.True or False

A) True
B) False

Question 18

Where is acid rain most recently becoming a major environmental problem?

A) Australia
B) China
C) India
D) South America

Question 19

Prior to 1900,what was the major source of atmospheric carbon dioxide?

A) The burning of fossil fuels
B) Rubber production
C) Deforestation
D) Livestock

Question 20

Phosphorus cycles within ecosystems,but the vast majority of phosphorus is stored where?

A) Land plants
B) Ocean Sediments
C) Mineable rock
D) Animals

Question 21

If you conducted a whole-ecosystem experiment and manipulated temperature,which of the following would you expect to happen?

A) Overall, NEP would affected
B) NPP would be affected
C) Overall, NEP would not be affected
D) Ecosystem respiration would be affected

Question 22

Why do ocean waters become acidic as carbon dioxide is assimilated?

A) Carbon dioxide produces more hydrogen ions in salt water
B) Carbon dioxide is converted to calcium carbonate and that raises pH
C) Carbon dioxide dissolved in water converts to carbonic acid
D) Carbon dioxide does not play a role in ocean acidification

Question 23

If Earth's oceans are carbon dioxide sinks,that means that carbon dioxide should remain in oceans infinitely.Is that accurate?

A) Yes, the oceans are a sink and no carbon dioxide is ever released. This process explains ocean acidification.
B) No, the oceans are not sinks although they do assimilate carbon dioxide.
C) No, the carbon dioxide assimilated into the deep ocean in the Atlantic will eventually surface elsewhere and be released back into the atmosphere.
D) Yes, the oceans are a sink for carbon dioxide, but only in the Southern Indian and Pacific Oceans. In a few decades the carbon dioxide is assimilated by marine animals and released when they die.

Question 24

Which of the following are natural sources of methane?

A) Oceans
B) Wetlands and lakes
C) Ancient geological formations
D) Bacteria that oxidize organic carbon to carbon dioxide

Question 25

One outcome of increased atmospheric carbon dioxide is that more carbon dioxide is taken up by the ocean which resulted in?

A) Acidification of the ocean and a disruption of organisms with carbonate shells
B) An increase in ocean pH that could result in a crash of fish populations
C) The collapse of the life surrounding deep sea vents
D) An absence of available carbon dioxide for terrestrial systems

Question 26

Acid rain that results from sulfur pollution can cause which of the following problems?

A) Eutrophication
B) Loss of fish from lakes
C) Dieback of forests
D) Declines of plant species richness

Question 27

As carbon dioxide in the atmosphere increase and global temperature rises,what can be expected?

A) The ocean sink for atmospheric carbon dioxide will change
B) The terrestrial ecosystem sink for atmospheric carbon dioxide will change.
C) We will be able to predict with accuracy how these changes will occur
D) We will NOT be able to predict with accuracy how these changes will occur

Question 28

Since the late 19th century,which resource has shown the greatest overall increase in consumption?

A) Oil
B) Coal
C) Nuclear
D) Hydro

Question 29

Which of the following statements regarding methane as a greenhouse gas are correct?

A) Methane absorbs infrared radiation at a different wavelength than carbon dioxide
B) The wavelength at which methane absorbs radiation makes it a potent greenhouse gas
C) The concentration of methane in the atmosphere is greater than carbon dioxide, which is why global temperatures have risen so drastically over the last 100 years
D) Methane acts as a catalyst to produce ground-level ozone

Question 30

Which of the following are considered life-sustaining biophysical systems,as proposed by Rockstrom et al.?

A) The nitrogen cycle
B) The phosphorous cycle
C) The solar system
D) The waste cycle

Question 31

Which factors most influence the sinks of atmospheric carbon dioxide?

A) The nitrogen cycle being altered by human activities
B) The phosphorus cycle being altered by animals
C) The increased frequency of fires in the tundra biome
D) The loss of biodiversity

Question 32

How is it possible for scientists to know how much carbon dioxide is assimilated by the oceans?

A) Scientists actually do not know how much carbon dioxide is assimilated by the oceans. There are only crude estimates based off of models.
B) Scientists use ice cores to estimate how much carbon dioxide is assimilated by the oceans.
C) Scientists track this by using carbon in decayed and fossilized organisms from the deep sea.
D) Scientists can estimate how much carbon dioxide is assimilated by oceans with moderate precision because radioactive carbon dioxide from nuclear bombs can be tracked.

Question 33

Why does the flux of methane to the atmosphere from coastal marshes drop (relative to freshwater)to near zero?

A) Because salinity and sulfate increase which prevent methane formation
B) Because methanogenesis dominates
C) Because decrease in salinity is due to the increased concentration of sulfates in sea water
D) Because sulfate reduction is the dominant decomposition process in coastal marshes

Question 34

If you used a whole-ecosystem experiment to add carbon dioxide to forests,what effect would you expect these additional amounts of carbon dioxide to have?

A) Decrease NEP
B) Increase rates of NPP
C) Increase NEP
D) Decrease NPP

Question 35

What patterns do we see historically for the release of carbon dioxide to the atmosphere from tropical and temperate forests?

A) Deforestation in temperature forests remains a source of release even today
B) Around 1960 deforestation in temperate forests became less of a problem
C) Tropical forest emissions peaked in the 1990s but are still a major concern today
D) Temperate forest are likely still deforested at the same rate as tropical forests today

Question 36

How has human activity since the 19th century affected atmospheric concentrations of methane?

A) Since 1800, the atmospheric concentration of methane has more than doubled
B) Since 1800, the atmospheric concentration of methane has increased by less than 200%
C) Has increased at a rate even faster than carbon dioxide
D) The increase has been associated with biomass burning and the creation of landfills

Question 37

As atmospheric carbon dioxide levels have increased,the higher concentration should increase the diffusion of carbon dioxide into the oceans.However,there is a reduced net rate of carbon dioxide uptake by oceans.Why?

A) This is due to supersaturation of the oceans and the inability of any more carbon dioxide to be assimilated.
B) This is due to decreased atmospheric temperatures that decrease the solubility of carbon dioxide.
C) This is the result of increased atmospheric temperatures that increase the solubility of carbon dioxide.
D) The reduced net rate of carbon dioxide uptake is due to increased surface ocean temperatures that lower the solubility of carbon dioxide.

Question 38

Anthropogenic sources of methane include which of the following?

A) Decomposition of organic matter in landfills
B) Bacterial methanogenesis
C) Deforestation
D) Animal agriculture

Question 39

Which of the following statements is correct?

A) Hydro electricity accounts for greater than a fifth of the non-renewable sources of energy used in 2010.
B) Coal and Oil represent greater than 50% of the total percentage of non-renewable resources consumed.
C) Wood is considered a non-renewable source of energy
D) All of the above

Question 40

Scientists say that that the global rate of terrestrial net ecosystem production (NEP)is approximately 56.4 Pg of carbon per year.However,there may be 30% or more uncertainty in these rates.What does that mean?

A) That the NEP is exactly 56.4 Pg of carbon per year and that it does not fluctuate
B) That the global NEP is inferred from data, and that there may be plus or minus 30% of 56.4 Pg of carbon per year
C) That the global NEP is absolute, and that it will likely be higher than 56.4 Pg of carbon per year
D) That the NEP is not reliable because there is 30% or more uncertainty. Therefore we should not trust the estimate.

Question 41

The greatest contribution to the total human input of nitrogen per year in is __________.

A) Fossil fuels burning
B) Nitrogen fixation associate with agricultural crops
C) Manufacturing of synthetic fertilizer
D) Deforestation

Question 42

One reason why the melting of oceanic ice will potentially be problematic for the atmosphere and global warming is _____________.

A) Because less greenhouse gases will be absorbed by ice
B) Because the ice holds huge quantities of gaseous methane
C) Because the ice holds huge deposits of carbon dioxide
D) Because it provides habitat for all polar animals

Question 43

The use of high-volume hydraulic fracturing techniques to release natural gas from shale is of major concern because ____________.

A) Scientists have identified that natural gas from shale may have mercury in it
B) Shale natural gas is composed largely of the greenhouse gas methane
C) Shale natural gas is composed of chlorofluorocarbons that pollute the environment
D) Scientists know that shale natural gas is bad for the environment but not as bad as coal

Question 44

Coastal marshes contribute little to no methane to the atmosphere due to high levels of ________.

A) Nitrogen
B) Carbon
C) Sulfate
D) None of the above

Question 45

The use of fertilizer has produced mixed environmental outcomes.Why?

A) Because it has promoted more crop growth but also an increase in plant diseases
B) Because it has promoted more food and less starvation but has also led to aquatic dead zones and amphibian deformities
C) Because it has led to less hunger and more biodiverse oceans
D) Because it has produced less hunger and fewer human related cancers

Question 46

Using Figure 12.24,it appears that ________________ has used the most synthetic nitrogen fertilizer between 2001 and 2011?

A) Africa
B) East Asia
C) Australia
D) Latin America

Question 47

The slowing of the great oceanic conveyor belts and the increased frequency of burn events in the tundra biome are evidence that __________.

A) The world is increasing its risk towards reaching some tipping point in the global climate system
B) The flux of methane has decreased
C) Solar radiation is warming the planet
D) There is nothing to worry about because these events have happened historically and are a part of Earth's natural climatic fluctuations

Question 48

Amphibian disease may be related to fertilizer production because?

A) Fertilizer promotes frog egg deformities
B) Fertilizer promotes increases in DNA breakdown in the frogs
C) Fertilizer enhances habitats for frog predators
D) Fertilizer enhances an intermediate host of a frog parasite

Question 49

You might say that fertilizer has an indirect negative effect on amphibians because:

A) Fertilizer promotes algae which in turn promotes an intermediate host for a harmful amphibian parasite
B) Fertilizer directly disrupts amphibian development
C) Fertilizer promotes algae which is what frog tadpoles feed on
D) Fertilizer promotes algae which in turn produces more frog predators

Question 50

Methane produced in the late 20th and early 21st centuries is distinguishable from ancient sources of methane by using _________.

A) Molecular markers to detect SNPs from ancient microorganisms
B) An Isotope that is associated with radiation that has a half life of more than 5,000 years
C) Testing remains of decaying animals
D) None of the above