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IB Biology D4.3: Climate Change — Practice Questions & Answers
IB Biology D4.3 Climate change study notes: greenhouse effect, carbon dioxide and methane, consequences for ecosystems and possible responses.
Here are 10 practice questions with full answers and explanations.
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Practice questions with answers
1
Multiple choice
What are the direct consequences of rising carbon dioxide levels in the atmosphere?
Increased greenhouse effect and global warming.
Increased oxygen production.
Decreased species diversity.
Decreased water availability.
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Why Rising carbon dioxide directly enhances the greenhouse effect, causing global warming.
2
Multiple choice
What are the indirect consequences of rising carbon dioxide levels in the atmosphere?
Changes in climate patterns and ocean acidification.
Increased nutrient cycling.
Increased primary production.
Increased energy transfer efficiency.
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Why Indirect effects of rising carbon dioxide include shifting climate patterns and ocean acidification.
3
Multiple choice
What is a primary anthropogenic cause of climate change?
Volcanic eruptions
Natural forest fires
Solar flares
Increased atmospheric carbon dioxide
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Why Rising atmospheric carbon dioxide from burning fossil fuels is the primary human driver of climate change.
4
Multiple choice
What is a positive feedback cycle in global warming?
Decreased volcanic activity
Enhanced cloud formation
Increased plant photosynthesis
Release of carbon dioxide from deep ocean
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Why Warming that releases stored carbon dioxide from the deep ocean is a positive feedback amplifying global warming.
5
Multiple choice
What is a potential tipping point in boreal forests due to climate change?
Change from net carbon accumulation to net loss
Increased winter snowfall
Enhanced biodiversity
Increased primary production
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Why A tipping point in boreal forests is the shift from net carbon storage to becoming a net carbon source.
6
Multiple choice
What is a potential impact of melting landfast ice in the Antarctic?
Increased ocean nutrient upwelling
Enhanced coral reef growth
Loss of emperor penguin breeding grounds
Increased walrus populations
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Why Melting landfast ice destroys the stable platform emperor penguins need for breeding.
7
Multiple choice
What can warmer surface water prevent in ocean currents?
Increased salinity
Enhanced photosynthesis
Nutrient upwelling
Increased marine biodiversity
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Why Warmer, less dense surface water resists mixing, preventing the upwelling of deep nutrients.
8
Multiple choice
What is a common range shift of temperate species due to climate change?
Poleward and upslope shifts
No shifts
Downslope and equatorward shifts
Random shifts
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Why As climates warm, temperate species shift their ranges poleward and to higher elevations to track suitable conditions.
9
Multiple choice
What is a major threat to coral reefs due to increased carbon dioxide?
Enhanced calcification
Ocean acidification
Increased coral growth
Decreased water temperature
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Why Rising carbon dioxide dissolves in seawater to form carbonic acid, causing ocean acidification that threatens reefs.
10
Multiple choice
What is a major threat to coral reefs due to increased water temperature?
Decreased salinity
Increased coral reproduction
Enhanced nutrient uptake
Coral bleaching
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Why Higher water temperatures cause coral bleaching as stressed corals expel their symbiotic zooxanthellae.
Key terms in Climate Change
Greenhouse effect: The warming of the lower atmosphere caused by gases absorbing and re-radiating infrared radiation emitted by the Earth’s surface.
Enhanced greenhouse effect: The intensified warming caused by human activities raising the concentration of greenhouse gases.
Greenhouse gas: A gas, such as carbon dioxide or methane, that absorbs outgoing infrared radiation and contributes to warming.
Infrared radiation: Long-wavelength (heat) radiation re-emitted by the warmed Earth’s surface and absorbed by greenhouse gases.
Carbon sink: A reservoir, such as a forest or the ocean, that absorbs more carbon dioxide than it releases.
Ocean acidification: The lowering of ocean pH as it absorbs carbon dioxide, harming corals and shell-forming organisms.
Phenology: The timing of seasonal biological events such as flowering, breeding and migration, increasingly shifted by warming.
Carbon cycle: The movement of carbon between the atmosphere, organisms, oceans and rocks through processes such as photosynthesis, respiration and combustion.
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