D4.3 climate change (year 6) Flashcards
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Name anthropogenic (human) causes of climate change/release of greenhouse gases (3)
- carbon dioxide is produced when fossil fuels are burnt
- natural carbon sinks are being cleared (deforestation)
- methane produced by livestock such as cattle and certain agriculture cultivations like rice
Global warming positive feedback loops (5)
- carbon dioxide is released from deep sea decomposers such as bacteria and archaea when they consume the corpses of marine animals that sink to the bottom of the sea
- increase in absorption of solar radiation from loss of reflective snow/ice
- accelerating rates of decomposition of peat and previously undecomposed organic matter in permafrost
- release of methane from melting permafrost
- increases in droughts and forest fires
what is a tipping point + example
Tipping point: threshold that when crossed leads to accelerating and irreversible changes in climate system
Example: in taigas, warmer temperatures and decreased winter snowfall leads to increased incidence of drought, leading to forest browning (dropping of leaves from coniferous trees due to lack of water for photosynthesis) and increase in intensity and frequency of forest fires, leading to legacy carbon combustion (carbon trapped in soil being released from the fires)
example of polar habitat change (2)
Melting of landfast ice and sea ice
- loss of breeding grounds of emperor penguin (Aptenodytes forsteri) due to breakout of landfast ice in antarctic
- loss of breeding ground of walrus (Odobenus rosmarus) due to melting sea ice in arctic
effects of ocean current change
Warmer surface water prevents timing and extent of nutrient upwelling to surface, decreasing ocean primary production and energy through marine food chains
example of poleward (higher latitude) range shift
tree species in north america have been moving polewards due to increasing temperatures
example of upslope (higher elevation) range shift
montane birds (birds that live on mountains) have been moving upslope due to increasing temperatures, sensitive to temps
example of ecosystem collapse
collapse of reef ecosystems
increased carbon dioxide concentrations causes ocean acidification and suppression of calcification in corals
higher water temperatures cause coral bleaching
examples of carbon sequestration (removing carbon added to atmosphere)
- afforestation (planting trees where there were no forests before)
- reforestation
- restoration of peat forming wetlands
example of disruption of synchrony of phenological events (essay qn)
Reindeer (Rangifer tarandus) use day length to know when to return to breeding grounds
Plants they eat, mouse-ear chickweed (Cerastium arcticum), depend on temperature to come out of dormancy, but with rising temperatures this makes their peak production time come earlier
There might not be sufficient plants to provide enough nourishment to the reindeer to produce enough calves to maintain population
This is called trophic mismatch
effect of climate change on insect life cycles
Increase in number of insect life cycles within a year due to climate change
Spruce bark beetle (Ips typographus or Dedroctonus micans) life cycles depend on temperature. Warmer temperatures with milder and shorter winters enable more life cycles per year
When the beetles emerge they could have a negative economic impact on timber industries by eating wood under the bark of spruce tree. However, this also means they kill off less healthy trees
example of evolution due to climate change
Changes in the fitness of colour variants of the tawny owl (Strix aluco) - polymorphism
Increase in brown morph of tawny owl compared to white morph due to milder winters in Finland
No need to camouflage as much to catch prey due to less snow
