CAP Environmental Impact 2 — Questions and Answers
Question 1: Which greenhouse gas has the highest 100-year Global Warming Potential (GWP) among those commonly tracked in carbon audits?
- Carbon dioxide (CO₂)
- Methane (CH₄)
- Nitrous oxide (N₂O)
- Sulfur hexafluoride (SF₆) (Correct answer)
Correct answer: Sulfur hexafluoride (SF₆)
SF₆ has a 100-year GWP of approximately 23,500, making it the most potent GHG commonly tracked under the Kyoto Protocol basket.
Question 2: In life cycle assessment (LCA), which phase typically contributes the most to the carbon footprint of a manufactured steel product?
- Raw material extraction and processing (Correct answer)
- Product use phase
- End-of-life disposal
- Packaging and distribution
Correct answer: Raw material extraction and processing
For steel, raw material extraction and the energy-intensive smelting process (especially blast furnace operations) dominate the product's lifecycle carbon emissions.
Question 3: What does the concept of 'carbon sequestration' refer to in environmental impact assessments?
- The release of stored carbon from fossil fuels
- The process of capturing and storing atmospheric CO₂ (Correct answer)
- The measurement of carbon in soil samples
- The trading of carbon credits on exchanges
Correct answer: The process of capturing and storing atmospheric CO₂
Carbon sequestration is the long-term capture and storage of atmospheric CO₂ in reservoirs such as forests, soils, oceans, or geological formations.
Question 4: A company's Scope 3 emissions include which of the following?
- On-site combustion of natural gas for heating
- Purchased electricity consumed at company facilities
- Business air travel by employees (Correct answer)
- Emissions from company-owned vehicle fleet
Correct answer: Business air travel by employees
Employee business travel is a Scope 3 Category 6 emission because it occurs in assets not owned or controlled by the reporting company.
Question 5: Which land-use change activity is a major contributor to global greenhouse gas emissions according to the IPCC?
- Converting farmland to urban development
- Deforestation of tropical rainforests (Correct answer)
- Planting cover crops on agricultural land
- Converting wetlands to managed grasslands
Correct answer: Deforestation of tropical rainforests
Tropical deforestation releases enormous amounts of stored carbon and eliminates carbon sinks, making it one of the largest land-use emission sources globally.
Question 6: When assessing the environmental impact of aviation emissions, auditors apply a Radiative Forcing Index (RFI) because:
- Aviation fuel is more carbon-intensive per liter than diesel
- Non-CO₂ effects at altitude amplify the climate impact beyond CO₂ alone (Correct answer)
- Aircraft emit more methane than ground vehicles
- International aviation is excluded from national GHG inventories
Correct answer: Non-CO₂ effects at altitude amplify the climate impact beyond CO₂ alone
Aviation's non-CO₂ effects — contrail formation, ozone creation, and cirrus cloud impacts at high altitude — multiply its effective climate warming beyond the CO₂ emissions alone.
Question 7: Which metric best quantifies the long-term environmental impact of a single molecule of methane compared to CO₂?
- Carbon Intensity Factor (CIF)
- Global Warming Potential (GWP) (Correct answer)
- Emissions Factor (EF)
- Net Present Value of Carbon (NPVC)
Correct answer: Global Warming Potential (GWP)
GWP expresses how much heat a greenhouse gas traps over a specific time horizon (typically 20 or 100 years) relative to CO₂, enabling comparison of different gases.
CAP Environmental Impact 2
Which greenhouse gas has the highest 100-year Global Warming Potential (GWP) among those commonly tracked in carbon audits?