Climate Change Causes & Effects 3 — Questions and Answers
Question 1: What is the 'carbon cycle' and how has human activity disrupted it?
- A natural process balanced by human fossil fuel emissions
- Natural exchanges of carbon between land, ocean, and atmosphere that humans have unbalanced by releasing stored carbon (Correct answer)
- A government policy framework for carbon accounting
- The process by which plants convert CO2 into oxygen
Correct answer: Natural exchanges of carbon between land, ocean, and atmosphere that humans have unbalanced by releasing stored carbon
Burning fossil fuels releases carbon that was stored underground for millions of years, overwhelming natural carbon sinks and raising atmospheric CO2 levels.
Question 2: How does deforestation contribute to climate change beyond removing carbon sinks?
- It has no impact beyond reducing carbon absorption
- Trees release CO2 when cut or burned, adding to atmospheric carbon (Correct answer)
- Deforestation only affects local weather, not global climate
- It reduces rainfall, which cools the planet
Correct answer: Trees release CO2 when cut or burned, adding to atmospheric carbon
When forests are cleared and burned, all the carbon stored in trees is released as CO2, making deforestation both a source and a lost sink.
Question 3: What is 'thermal expansion' in the context of sea level rise?
- The expansion of Arctic land mass as permafrost thaws
- Warming ocean water physically expands in volume, contributing to sea level rise (Correct answer)
- The growth of coral reefs that raise sea floor levels
- Increased evaporation that reduces overall ocean volume
Correct answer: Warming ocean water physically expands in volume, contributing to sea level rise
Water expands as it warms, and since oceans are vast and deep, even small temperature increases produce significant sea level contributions from thermal expansion.
Question 4: Which gas, though emitted in smaller quantities than CO2, has roughly 80 times more warming potential over 20 years?
- Nitrous oxide
- Ozone
- Methane (Correct answer)
- Water vapor
Correct answer: Methane
Methane (CH4) has a global warming potential approximately 80 times that of CO2 over a 20-year period, making its reduction critically important.
Question 5: How does climate change affect hurricane intensity?
- Climate change has no proven effect on hurricane strength
- Warmer ocean temperatures provide more energy, increasing the intensity of storms (Correct answer)
- Climate change reduces hurricane frequency by disrupting wind patterns
- Cooler deep ocean water created by climate change weakens hurricanes
Correct answer: Warmer ocean temperatures provide more energy, increasing the intensity of storms
Hurricanes draw energy from warm ocean water, so as surface temperatures rise, storms can become more intense and carry more moisture.
Question 6: What is 'climate sensitivity' as used by climate scientists?
- How sensitive ecosystems are to temperature changes
- The estimated temperature rise from a doubling of atmospheric CO2 (Correct answer)
- The speed at which climate models update with new data
- A measure of how quickly humans respond to climate threats
Correct answer: The estimated temperature rise from a doubling of atmospheric CO2
Climate sensitivity refers to the equilibrium global mean temperature increase expected if CO2 concentrations double, typically estimated at 2.5–4°C.
Question 7: Which feedback mechanism involves increased water vapor amplifying warming caused by CO2?
- The ice-albedo feedback
- The water vapor feedback (Correct answer)
- The cloud radiative effect
- The lapse rate feedback
Correct answer: The water vapor feedback
As CO2 warms the atmosphere, more water evaporates; since water vapor is itself a greenhouse gas, this further amplifies warming in a positive feedback loop.
Climate Change Causes & Effects 3
What is the 'carbon cycle' and how has human activity disrupted it?