Home › IB Biology › Practice › Climate ChangeIB Diploma · Biology D4.3
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.
Start an interactive IB Biology quiz →
Practice questions with answers
1
Multiple choice
What is a primary anthropogenic cause of climate change?
Increased atmospheric carbon dioxide
Volcanic eruptions
Solar flares
Natural forest fires
Tap an answer to check it.
Why Rising atmospheric carbon dioxide from burning fossil fuels is the primary human driver of climate change.
2
Multiple choice
What is a positive feedback cycle in global warming?
Release of carbon dioxide from deep ocean
Increased plant photosynthesis
Enhanced cloud formation
Decreased volcanic activity
Tap an answer to check it.
Why Warming that releases stored carbon dioxide from the deep ocean is a positive feedback amplifying global warming.
3
Multiple choice
What is a potential tipping point in boreal forests due to climate change?
Change from net carbon accumulation to net loss
Increased primary production
Enhanced biodiversity
Increased winter snowfall
Tap an answer to check it.
Why A tipping point in boreal forests is the shift from net carbon storage to becoming a net carbon source.
4
Multiple choice
What is a potential impact of melting landfast ice in the Antarctic?
Loss of emperor penguin breeding grounds
Increased walrus populations
Enhanced coral reef growth
Increased ocean nutrient upwelling
Tap an answer to check it.
Why Melting landfast ice destroys the stable platform emperor penguins need for breeding.
5
Multiple choice
What can warmer surface water prevent in ocean currents?
Nutrient upwelling
Increased salinity
Enhanced photosynthesis
Increased marine biodiversity
Tap an answer to check it.
Why Warmer, less dense surface water resists mixing, preventing the upwelling of deep nutrients.
6
Multiple choice
What is a common range shift of temperate species due to climate change?
Poleward and upslope shifts
Downslope and equatorward shifts
Random shifts
No shifts
Tap an answer to check it.
Why As climates warm, temperate species shift their ranges poleward and to higher elevations to track suitable conditions.
7
Multiple choice
What is a major threat to coral reefs due to increased carbon dioxide?
Ocean acidification
Increased coral growth
Decreased water temperature
Enhanced calcification
Tap an answer to check it.
Why Rising carbon dioxide dissolves in seawater to form carbonic acid, causing ocean acidification that threatens reefs.
8
Multiple choice
What is a major threat to coral reefs due to increased water temperature?
Coral bleaching
Increased coral reproduction
Decreased salinity
Enhanced nutrient uptake
Tap an answer to check it.
Why Higher water temperatures cause coral bleaching as stressed corals expel their symbiotic zooxanthellae.
9
Multiple choice
What is an approach to carbon sequestration?
Afforestation
Deforestation
Increased fossil fuel use
Urbanization
Tap an answer to check it.
Why Afforestation sequesters carbon by planting new forests whose trees absorb carbon dioxide during growth.
10
Multiple choice
What type of wetlands are important for carbon sequestration?
Peat-forming wetlands
Salt marshes
Mangroves
Tidal flats
Tap an answer to check it.
Why Peat-forming wetlands are important carbon sinks, locking away carbon in waterlogged, undecomposed organic matter.
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.
See the full study notes for this topic.
Practise other IB Biology topics