Climate Change Environmental Science Fundamentals 2 — Questions and Answers
Question 1: Which ocean current system plays a critical role in redistributing heat globally and is vulnerable to disruption by freshwater influx from melting ice?
- El Niño Southern Oscillation
- Atlantic Meridional Overturning Circulation (Correct answer)
- Pacific Decadal Oscillation
- Indian Ocean Dipole
Correct answer: Atlantic Meridional Overturning Circulation
The Atlantic Meridional Overturning Circulation (AMOC) transports warm surface water northward and cold deep water southward, but freshwater from melting glaciers can weaken this conveyor belt.
Question 2: What is the primary reason permafrost thaw is considered a climate change 'tipping point'?
- It raises sea levels directly
- It releases stored carbon as CO₂ and methane, amplifying warming (Correct answer)
- It destroys Arctic ecosystems completely
- It blocks sunlight by releasing aerosols
Correct answer: It releases stored carbon as CO₂ and methane, amplifying warming
Permafrost stores vast amounts of organic carbon; when it thaws, microbial decomposition releases CO₂ and methane, creating a positive feedback loop that accelerates warming.
Question 3: Which biogeochemical cycle is most directly disrupted when fossil fuels are burned?
- Nitrogen cycle
- Phosphorus cycle
- Carbon cycle (Correct answer)
- Sulfur cycle
Correct answer: Carbon cycle
Burning fossil fuels releases carbon that was sequestered underground for millions of years back into the atmosphere, disrupting the natural carbon cycle balance.
Question 4: Ocean acidification caused by absorbed CO₂ most directly threatens which marine organisms?
- Bony fish and sharks
- Organisms that build calcium carbonate shells or skeletons (Correct answer)
- Seagrasses and kelp forests
- Deep-sea thermal vent communities
Correct answer: Organisms that build calcium carbonate shells or skeletons
Carbonic acid formed when CO₂ dissolves in seawater lowers pH, making it harder for corals, mollusks, and echinoderms to build and maintain their calcium carbonate structures.
Question 5: What distinguishes 'radiative forcing' as a concept in climate science?
- The rate at which the Earth rotates affecting temperature distribution
- The imbalance between incoming solar radiation and outgoing infrared radiation (Correct answer)
- The reflection of sunlight by ice and snow surfaces
- The transfer of heat through ocean currents
Correct answer: The imbalance between incoming solar radiation and outgoing infrared radiation
Radiative forcing measures the change in energy flux in the atmosphere caused by natural or anthropogenic factors, with positive values indicating net warming and negative values indicating net cooling.
Question 6: Which US region is projected to face the greatest increase in 'heat island' intensity as climate change progresses?
- Rural Midwest agricultural zones
- Dense urban areas in the South and Southwest (Correct answer)
- Coastal Pacific Northwest cities
- Appalachian mountain communities
Correct answer: Dense urban areas in the South and Southwest
Urban areas in the South and Southwest already experience intense heat, and climate change combined with the urban heat island effect—where pavement and buildings trap heat—will amplify temperatures most severely there.
Question 7: What is the concept of 'planetary boundaries' in environmental science?
- The physical limits of Earth's atmosphere in altitude
- A framework defining safe operating limits for Earth's major systems (Correct answer)
- National borders that affect pollution dispersion
- The maximum number of species an ecosystem can support
Correct answer: A framework defining safe operating limits for Earth's major systems
Planetary boundaries identify nine Earth system processes with thresholds that, if crossed, could destabilize the planet's relatively stable Holocene conditions that human civilization depends on.
Climate Change Environmental Science Fundamentals 2
Which ocean current system plays a critical role in redistributing heat globally and is vulnerable to disruption by freshwater influx from melting ice?