Lecture 3 Flashcards
Which of the following is NOT a significant contributor to global sea-level rise?
a. Thermal expansion of oceans
b. Melting of mountain glaciers
c. Decreased volcanic activity
d. Ice loss from Greenland and Antarctic ice sheets
c.
Explanation: Volcanic activity does not significantly contribute to sea-level rise.
What is the primary source of anthropogenic methane emissions?
a. Landfills
b. Ruminant livestock
c. Rice production
d. Biomass burning
b.
Explanation: Enteric fermentation in ruminant livestock accounts for the largest share of anthropogenic methane emissions.
Which of these gases has the highest global warming potential (GWP) relative to CO₂?
a. Methane (CH₄)
b. Nitrous oxide (N₂O)
c. Chlorofluorocarbons (CFCs)
d. Carbon dioxide (CO₂)
c.
Explanation: CFCs have a GWP thousands of times greater than CO₂, despite their lower atmospheric concentrations.
Define the greenhouse effect.
The greenhouse effect is the process by which greenhouse gases trap heat in Earth’s atmosphere, warming the planet.
How does the melting of polar ice contribute to global warming?
Melting polar ice reduces the Earth’s albedo, leading to increased absorption of solar radiation and further warming.
What are Representative Concentration Pathways (RCPs)?
RCPs are scenarios that describe possible trajectories of greenhouse gas concentrations and their associated radiative forcing by 2100.
What is ocean acidification, and what causes it?
Ocean acidification refers to the lowering of ocean pH due to the absorption of CO₂, forming carbonic acid.
Explain how deforestation contributes to global warming.
Deforestation reduces the number of trees that absorb CO₂, increasing atmospheric CO₂ levels and enhancing the greenhouse effect.
What is a tipping point in the context of climate systems?
A tipping point is a threshold beyond which small changes can lead to irreversible and significant climate impacts.
Describe the role of methane in global warming.
Methane is a potent greenhouse gas with a high GWP. It traps heat effectively and contributes significantly to radiative forcing.
How do feedback loops amplify global warming?
Feedback loops, such as reduced albedo or permafrost thaw, create self-reinforcing cycles that accelerate warming.
What is phenology, and how is it affected by climate change?
Phenology is the timing of biological events. Climate change alters phenological patterns, such as earlier flowering or migration.
Why is the Arctic warming faster than other regions?
Arctic amplification occurs because ice and snow melt reduces albedo, leading to more heat absorption and faster warming.
What is the impact of climate change on species’ geographical ranges?
Many species are shifting poleward or to higher elevations to track their preferred climate conditions.
Explain how managed relocation can help species adapt to climate change.
Managed relocation involves moving species to new habitats where they are more likely to survive under changing climate conditions.
Analyze the role of nitrous oxide in global warming.
Nitrous oxide is a greenhouse gas with a GWP over 300 times greater than CO₂. Its emissions primarily result from agriculture, where fertilizers and nitrogen-fixing crops intensify nitrogen cycling.
Evaluate the long-term effects of permafrost thawing on the global carbon cycle.
Permafrost thaw releases stored carbon as CO₂ and methane, creating a positive feedback loop that accelerates global warming and disrupts carbon balance.
Compare the risks and benefits of managed relocation as a conservation strategy.
Managed relocation can prevent extinctions by moving species to viable habitats but risks disrupting ecosystems and failing due to uncertainty in climate projections.
Case Study: Bramble Cay Melomys Extinction
Question: What lessons can be learned from the extinction of the Bramble Cay melomys regarding climate change impacts on biodiversity?
The case highlights the vulnerability of low-lying islands to sea-level rise and storm surges, emphasizing the need for proactive conservation measures.
Case Study: Arctic Sea Ice Loss
Question: Discuss the ecological and climatic implications of declining Arctic sea ice.
Loss of sea ice disrupts habitats for species like polar bears and seals, increases ocean absorption of heat, and alters global weather patterns.
