Impacts on natural systems
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Flip to reveal answersState two physical impacts of climate change on Earth systems.
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All 20 Flashcards — Impacts on natural systems
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Question
State two physical impacts of climate change on Earth systems.
Answer
Examples include rising global temperatures, melting glaciers/ice sheets, sea level rise, permafrost thaw, and increased frequency/intensity of extreme weather events.
💡 Hint
Any two big physical changes.
Question
What is meant by a species “range shift” due to climate change?
Answer
A range shift is when a species’ geographic distribution moves (often poleward or to higher altitude) to track suitable temperatures and conditions as climate warms.
💡 Hint
Move to stay cool.
Question
List three key impacts of climate change on natural systems.
Answer
Examples include sea level rise, melting glaciers/ice sheets, more extreme weather, species range shifts, ocean acidification, and coral bleaching.
💡 Hint
Any three natural-system impacts.
Question
State two processes linked to climate change that can cause sea level rise.
Answer
Thermal expansion of seawater, and melting of land-based ice (glaciers/ice sheets).
💡 Hint
Two causes only.
Question
What are the two main causes of global sea level rise linked to climate change?
Answer
Thermal expansion of seawater as it warms, and melting of land-based ice (glaciers and ice sheets).
💡 Hint
Expansion + land ice melt.
Question
Explain why glacier-fed river flow may first increase and then decrease as glaciers retreat.
Answer
Initially, increased melting adds extra runoff. Over time, glacier volume shrinks so there is less ice left to melt, reducing dry-season flow.
💡 Hint
Early boost, later drop.
Question
Define phenology and give one example of a phenological change linked to climate warming.
Answer
Phenology is the timing of seasonal biological events. Example: earlier flowering, earlier insect emergence, or earlier bird migration due to warmer springs.
💡 Hint
Timing of life-cycle events.
Question
In an exam “explain impacts on ecosystems” question, what structure usually scores best?
Answer
Use cause → effect chains. State the climate driver (warming, drought, sea level, acidification), then the biological/physical change, then the consequence for populations and biodiversity.
💡 Hint
Driver → change → consequence.
Question
Suggest how increased atmospheric CO2 can cause thinner shells in oysters.
Answer
CO2 dissolves forming carbonic acid, lowering pH and reducing carbonate ions needed to form calcium carbonate. Shell formation becomes harder and shells can be thinner.
💡 Hint
CO2 → lower pH → fewer carbonates.
Question
Explain how ocean warming can lead to coral bleaching.
Answer
Sustained high sea temperatures stress corals, causing them to expel symbiotic algae (zooxanthellae). Corals lose colour and a major energy source, increasing mortality risk.
💡 Hint
Heat stress → algae expelled.
Question
What is the key difference between ocean warming and ocean acidification?
Answer
Ocean warming is a temperature increase that stresses organisms (e.g., coral bleaching). Ocean acidification is a pH decrease from dissolved CO2 that reduces carbonate availability for shells/skeletons.
💡 Hint
Warming = temperature; Acidification = pH.
Question
Define thermal expansion in the context of sea level rise.
Answer
Thermal expansion is the increase in volume of seawater as it warms, which raises sea level even without adding extra water.
💡 Hint
Warm water takes up more space.
Question
Does melting sea ice significantly raise sea level? Explain.
Answer
No. Sea ice is already floating, so when it melts it largely displaces the same volume of water. Melting land ice raises sea level because it adds water to the ocean.
💡 Hint
Floating ice vs land ice.
Question
What is ocean acidification and why does it harm shell-forming organisms?
Answer
Ocean acidification is the decrease in ocean pH as CO2 dissolves forming carbonic acid. It reduces carbonate ions, making it harder for organisms to build calcium carbonate shells/skeletons.
💡 Hint
Lower pH → fewer carbonate ions.
Question
Explain how permafrost thaw can create a positive feedback to climate change.
Answer
Thaw allows decomposition of previously frozen organic matter, releasing CH4 and CO2, increasing the greenhouse effect and causing more warming and further thaw.
💡 Hint
Feedback loop wording.
Question
Give one named example of an ice-dependent organism and one impact of sea ice loss on it.
Answer
Example: polar bears. Reduced sea ice decreases access to hunting platforms for seals, reducing feeding success and affecting reproduction/survival.
💡 Hint
Organism + specific impact.
Question
A student says: “Melting sea ice will greatly raise global sea levels.” State whether this is correct and justify.
Answer
Not correct. Melting sea ice does not significantly raise sea level because it already floats. Sea level rises mainly from thermal expansion and melting land-based ice.
💡 Hint
Floating ice doesn’t add volume.
Question
Why is sea level rise often described as a major risk multiplier for ecosystems and coasts?
Answer
Rising sea level increases coastal flooding and erosion, pushes saltwater into wetlands and aquifers, and reduces habitat area for coastal ecosystems (e.g., mangroves and salt marshes).
💡 Hint
Flooding + erosion + salinisation.
Question
Give one example of a cause → effect chain showing how climate change can disrupt a food web.
Answer
Warming shifts plankton bloom timing (cause) → mismatch with fish larvae feeding period (effect) → lower fish survival → fewer prey for seabirds/marine mammals.
💡 Hint
Show a clear chain with links.
Question
Why can permafrost thaw create a positive feedback to climate change?
Answer
Thawing permafrost allows organic matter to decompose, releasing CO2 and methane (CH4). These greenhouse gases increase warming, causing more thaw.
💡 Hint
Thaw → GHG release → more warming.
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Full study notes for Impacts on natural systems
Topic 6.2 hub
Climate change—causes and impacts
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