BIOEE 1610: Post Prelim 3 Questions

Select all that serve as positive feedback loops to climate change: - Enhanced carbon sink in boreal forests due to longer growing seasons - Decreases of average forest albedo in boreal forests due to longer growing season (leaves are darker than ground and snow) - Increases of soil respiration due to higher temperature - Ocean acidification reduces productivity of phytoplankton - Increases of photosynthesis due to CO2 fertilization

- Decreases of average forest albedo in boreal forests due to longer growing season (leaves are darker than ground and snow) - Increases of soil respiration due to higher temperature - Ocean acidification reduces productivity of phytoplankton

Why is there a net land carbon sink?

- Forests are regrowing following agricultural abandonment - Net primary production increases with increasing atmospheric CO2 concentration (?)

What would the global mean temperature be without any greenhouse gases?

-15°C (average January low temperature in Quebec)

Relatively how much carbon goes to atmospheric sinks?

1/2

Relatively how much carbon goes to land sinks?

1/4

Relatively how much carbon goes to oceanic sinks?

1/4

What is the highest accumulated amount of CO2 that humans can further emit by the end of the 21st century to keep climate warming below 1.5°C?

100 Pg C

How much CO2 do plants assimilate global through photosynthesis annually?

10^17 grams of carbon

Which of the following annual carbon fluxes has the been the largest during the last 10 years> A) Fossil fuel and industrial emission B) Land use change emission C) Land carbon sink D) Ocean carbon sink E) Atmospheric carbon growth

A) Fossil fuel and industrial emissions

How do greenhouse gases contribute to global warming?

Absorb outgoing long-wave radiation

Select all that can be treated as evidence for environmental change: A) Major hurricanes hitting on a city for two consecutive years B) Annual precipitation has a decreasing trend in the past 50 years C) Occurrence of an 100-year flood (statistically only appears one every 100 years) D) Monotonic increases in sea water pH values E) Annual burnt area by wild fires kept increasing over the last few decades

B) Annual precipitation has a decreasing trend in the past 50 years D) Monotonic increases in sea water pH values E) Annual burnt area by wild fires kept increasing over the last few decades

Which of the following statements about deforestation is true? A) Currently, there is more deforestation occurring in temperature forests than tropical forests because more human agricultural happens to be in temperature zones B) Deforestations will incur CO2 emissions to the atmosphere due to tree biomass burning and decomposition. Additionally, soil carbon is lost following the removal of above ground tree biomass C) Deforestation currently contributes about the same carbon as fossil fuel burning to total anthropogenic emission D) All of the above E) None of the above

B) Deforestations will incur CO2 emissions to the atmosphere due to tree biomass burning and decomposition. Additionally, soil carbon is lost following the removal of above ground tree biomass

What three factors contribute the most to the zig-zags in the Keeling Curve? A) Oceans drive the change because of their large volume B) Plants are involved in carbon fixation C) The seasons are opposite in the northern and southern hemispheres D) There is more landmass in the northern hemisphere than in the southern hemisphere E) Annual changes in human behavior result in more fossil fuel use (heating) in the winter F) Respiration drives the change because so many animals are dormant in the winter

B) Plants are involved in carbon fixation C) The seasons are opposite in the northern and southern hemispheres D) There is more landmass in the northern hemisphere than in the southern hemisphere

In 2018, the IPCC published a special report advising to constrain global warming at 1.5°C by the end of the 21st century. Select all of the true statements about the 1.5°C target compared with the previous target of 2°C. A) The 1.5°C target allows humans to emit more CO2 into the atmosphere B) The 1.5°C target will reduce the risk of habitat loss for many species C) The 1.5°C target will reduce the chances of occurrences of an ice-free Arctic sea D) The 1.5°C target will make human adaptation efforts less challenging E) The 1.5°C target will reduce the probability of temperature extremes

B) The 1.5°C target will reduce the risk of habitat loss for many species C) The 1.5°C target will reduce the chances of occurrences of an ice-free Arctic sea D) The 1.5°C target will make human adaptation efforts less challenging E) The 1.5°C target will reduce the probability of temperature extremes

In 1991, a cataclysmic volcanic eruption occurred at Mount Pinatubo, Philippines. The eruption has emitted tons of dust into the atmosphere. In the subsequent years, the global temperature significantly decreased despite a previous warming trend. The cooling effect is mostly because? A) Volcanic eruption speeds us biogeochemical weathering that can take up atmospheric CO2 B) Volcanic eruption increases atmospheric aerosol that reflects more incoming solar radiation C) Volcanic eruption increases atmospheric aerosol that reflects more incoming long-wave radiation D) Volcanic eruption increases atmospheric aersol that traps more outgoing longwave radiation E) Volcanic eruption increases evaporative cooling of the land surface

B) Volcanic eruption increases atmospheric aerosol that reflects more incoming solar radiation - Aerosols increase albedo of the atmosphere and increases cloud formation that further blocks solar radiation

Under global warming, the soil carbon locked in the permafrost might be released. This process ____ A) will increase land carbon sink B) will reduce land carbon sink C) will have no effect on land carbon sink D) will reduce atmospheric carbon storage E) none of the above

B) will reduce land carbon sink

Based on your knowledge on the Keeling Curve, atmospheric CO2 concentration will generally increase or decrease from May to October? And where did the carbon come from (if increase) or go to (if decrease) A) Increased atmospheric CO2 coming from higher heterotrophic respiration B) Increased atmospheric CO2 coming from reduced primary production C) Decreased atmospheric CO2 due to enhanced terrestrial ecosystem carbon assimilation from the atmosphere D) Decreased atmospheric CO2 due to reduced heterotrophic respiration

C) Decreased atmospheric CO2 due to enhanced ecosystem carbon assimilation from the atmosphere

What is the main reason for a net ocean carbon sink?

CO2 diffuses into the ocean because ocean water has a lower CO2 concentration than the atmosphere

Is CO2 more soluble in cold or warm water?

Cold water

Goldenrod is competitively dominant in the grassland stage. What traits allow it to be competitively dominant? What traits drive it out?

Competitively dominant: - Many offspring, sexually (seed) and clonally (through tillering) - The most light capturing species in the community - Highly efficient at grabbing limiting nitrogen - Allelopathic (interference competition, chemically suppresses competitors through root exudates) Drives out: - Shade (exploitation competition)

What is the relationship between gall density and the probability of individual gall mortality due to predators and parasitoids?

Constant relationship (zero slope)

The current atmospheric CO2 concentration (~410 ppm) has not occurred in Earth history since the past: A) 1 thousand years B) 10 thousand years C) 100 thousand years D) 1 million years E) 10 million years

D) 1 million years AND E) 10 million years Likely only experienced more than 1 million or even 10 million years ago

Which of the following statements on climate warming detection is true? A) A few consecutive warm years can prove climate warming B) A few consecutive cold years can disprove climate C) Climate warming can only be detected when each year is warmer than the previous year D) Climate warming can be detected when there is a significant temporal increasing trend in temperature E) Climate warming can only be detected when temperature is warming than previous records everywhere on Earth

D) Climate warming can be detected when there is a significant temporal increasing trend in temperature

Since the Industrial Revolution, atmospheric CO2 concentration increased by ~115 ppm. Assume a rough converting factor of 2 Pg carbon per ppm CO2, which of the following statements is true about the cumulative anthropogenic carbon emissions that resulted in such an increase and why? A) Less than 230 Pg C because terrestrial ecosystems have been a carbon source due to plant respiration B) Less than 230 Pg C because ocean ecosystems have been a carbon source through CO2 diffusion into the atmosphere C) Exactly 230 Pg because ocean and land have stayed carbon neutral D) More than 230 Pg C because land and ocean have been carbon sinks and sequestered about half of anthropogenic carbon emissions

D) More than 230 Pg C because land and ocean have been carbon sinks and sequestered about half of anthropogenic carbon emissions

How does deforestation impact the global carbon cycle?

Deforestation results in carbon dioxide flux to the atmosphere as tree biomass is burned or decomposed, and soil organic carbon is respired

What is the relationship between gall density and the probability of mortality of young larvae (due to plant reaction)?

Direct relationship

What is the relationship between gall density and the probability of individual gall mortality?

Direct relationship - If there is some form of density dependence occurring, the probability of success, reproduction, or survival decreases

Select the most likely reason for why cherry blossoms are tending to bloom earlier each year: A) They have more nutrient availability for flowers due to increases in atmospheric nitrogen deposition B) They have more carbon availability for flowers due to CO2 fertilization C) Climate change led to more snow and precipitation in the winter and spring D) Climate change led to increased radiation in the winter and spring E) Urbanization and climate changes led to warmer winters and springs

E) Urbanization and climate changes led to warmer winters and springs

What are various carbon sources?

Fossil fuel emission Land use change through deforestation

What are the various carbon sinks?

Land carbon sinks Ocean carbon sinks Atmospheric accumulation

Which aspect of the global carbon cycle occurs faster? Biological or geologic?

biological is faster

Which aspect of the global carbon cycle is more intensive? Biological or geologic?

biological is more intensive

How does diffusion move?

from high to low concentration

How does ocean acidification affect the global carbon cycle?

more difficult to form CaCO3 shells (reduces biological pump)

How do positive feedbacks impact climate warming?

positive feedbacks reduce resilience to change