CAP Environmental Science Fundamentals 2 — Questions and Answers
Question 1: Which biogeochemical cycle is most directly disrupted by the combustion of fossil fuels?
- Nitrogen cycle
- Carbon cycle (Correct answer)
- Phosphorus cycle
- Sulfur cycle
Correct answer: Carbon cycle
Fossil fuel combustion releases carbon stored underground back into the atmosphere, directly disrupting the natural carbon cycle.
Question 2: What term describes the ability of Earth's surface and atmosphere to absorb and re-emit thermal radiation?
- Albedo effect
- Radiative forcing
- Greenhouse effect (Correct answer)
- Thermal inertia
Correct answer: Greenhouse effect
The greenhouse effect is the process by which greenhouse gases trap heat in the lower atmosphere by absorbing and re-emitting infrared radiation.
Question 3: Which ocean process absorbs approximately 25-30% of anthropogenic CO₂ emissions annually?
- Thermohaline circulation
- Ocean acidification
- Biological pump
- Air-sea gas exchange (Correct answer)
Correct answer: Air-sea gas exchange
Air-sea gas exchange (physical solubility pump) drives CO₂ dissolution from the atmosphere into ocean surface waters, accounting for roughly 25-30% of annual anthropogenic CO₂ uptake.
Question 4: In the context of climate science, what does 'radiative forcing' measure?
- The rate of solar energy reaching Earth's surface
- The change in energy flux caused by a climate driver (Correct answer)
- The total heat stored in the oceans
- The amount of CO₂ emitted per unit of energy
Correct answer: The change in energy flux caused by a climate driver
Radiative forcing measures the change in energy flux (W/m²) in the atmosphere caused by natural or anthropogenic factors, indicating whether the climate will warm or cool.
Question 5: Which of the following best describes a carbon 'sink'?
- A facility that emits large quantities of CO₂
- A reservoir that absorbs more carbon than it releases (Correct answer)
- A geological formation where CO₂ is extracted
- A measurement instrument for atmospheric carbon
Correct answer: A reservoir that absorbs more carbon than it releases
A carbon sink is any reservoir — such as forests, soils, or oceans — that absorbs and stores more carbon from the atmosphere than it releases.
Question 6: What is the primary driver of ocean acidification?
- Increased nitrogen runoff from agriculture
- Absorption of atmospheric CO₂ forming carbonic acid (Correct answer)
- Industrial discharge of sulfuric acid
- Rising ocean temperatures reducing pH buffering
Correct answer: Absorption of atmospheric CO₂ forming carbonic acid
When seawater absorbs CO₂, it reacts with water to form carbonic acid (H₂CO₃), which dissociates and lowers ocean pH, causing acidification.
Question 7: Which layer of the atmosphere contains the ozone layer that protects Earth from UV radiation?
- Troposphere
- Stratosphere (Correct answer)
- Mesosphere
- Thermosphere
Correct answer: Stratosphere
The ozone layer is located in the stratosphere, approximately 15–35 km above Earth's surface, where it absorbs harmful ultraviolet radiation.
CAP Environmental Science Fundamentals 2
Which biogeochemical cycle is most directly disrupted by the combustion of fossil fuels?