D4.3 Climate change Flashcards
D4.3.1—Anthropogenic causes of climate change
Limit to anthropogenic increases in atmospheric concentrations of carbon dioxide and methane.
NOS: Students should be able to distinguish between positive and negative correlation and should also
distinguish between correlation and causation. For example, data from Antarctic ice cores shows a positive
correlation between global temperatures and atmospheric carbon dioxide concentrations over hundreds
of thousands of years. This correlation does not prove that carbon dioxide in the atmosphere increases
global temperatures, although other evidence confirms the causal link.
D4.3.2—Positive feedback cycles in global warming
Include release of carbon dioxide from deep ocean, increases in absorption of solar radiation due to loss of
reflective snow and ice, accelerating rates of decomposition of peat and previously undecomposed
organic matter in permafrost, release of methane from melting permafrost and increases in droughts and
forest fires
D4.3.3—Change from net carbon accumulation to net loss in boreal forests as an example of a tipping
point
Include warmer temperatures and decreased winter snowfall leading to increased incidence of drought
and reductions in primary production in taiga, with forest browning and increases in the frequency and
intensity of forest fires, which result in legacy carbon combustion.
D4.3.4—Melting of landfast ice and sea ice as examples of polar habitat change
Include potential loss of breeding grounds of the emperor penguin (Aptenodytes forsteri) due to early
breakout of landfast ice in the Antarctic and loss of sea ice habitat for walruses in the Arctic.
D4.3.5—Changes in ocean currents altering the timing and extent of nutrient upwelling
Warmer surface water can prevent nutrient upwelling to the surface, decreasing ocean primary production
and energy flow through marine food chains.
D4.3.6—Poleward and upslope range shifts of temperate species
As evidence-based examples, include upslope range shifts for tropical-zone montane bird species in New
Guinea and range contraction and northward spread in North American tree species.
D4.3.7—Threats to coral reefs as an example of potential ecosystem collapse
Increased carbon dioxide concentrations are the cause of ocean acidification and suppression of
calcification in corals. Increases in water temperature are a cause of coral bleaching. Loss of corals causes
the collapse of reef ecosystems.
D4.3.8—Afforestation, forest regeneration and restoration of peat-forming wetlands as approaches to
carbon sequestration
NOS: There is active scientific debate over whether plantations of non-native tree species or rewilding
with native species offer the best approach to carbon sequestration. Peat formation naturally occurs in
waterlogged soils in temperate and boreal zones and also very rapidly in some tropical ecosystems
D4.3.9—Phenology as research into the timing of biological events
Students should be aware that photoperiod and temperature patterns are examples of variables that
influence the timing of biological events such as flowering, budburst and bud set in deciduous trees, bird
migration and nesting.
D4.3.10—Disruption to the synchrony of phenological events by climate change
Students should recognize that within an ecosystem temperature may act as the cue in one population
and photoperiod may be the cue in another. Include spring growth of the Arctic mouse-ear chickweed
(Cerastium arcticum) and arrival of migrating reindeer (Rangifer tarandus) as one example. Also include a
suitable local example or use the breeding of the great tit (Parus major) and peak biomass of caterpillars in
north European forests as another.
D4.3.11—Increases to the number of insect life cycles within a year due to climate change
Use the spruce bark beetle (Ips typographus or Dendroctonus micans) as an example.
D4.3.12—Evolution as a consequence of climate change.
Include changes in the fitness of colour variants of the tawny owl (Strix aluco) as a consequence of changes
in snow cover
