Global climate system links to carbon and water cycles. Flashcards
What human activities are impacting the carbon and water cycles?
- Increasing demand for food, fuel and other resources.
Why does deforestation occur?
For timber or to make space.
How many hectares a deforestated every year?
10 million hectares
What impacts does deforestation have on the water cycle?
- reduced interception
- increased erosion and surface run-off
What impacts does deforestation have on the carbon cycle?
- Reduce storage in soil and biomass.
- Reduce carbon dioxide intake during photosynthesis
- Increased carbon influx to atmosphere by burning and decomposing vegetation.
Why are oceans acidifying?
They are carbon sinks, but their uptake of carbon is increasing, causing pH to decrease
What are the impacts of ocean acidification?
- Increased risk of marine ecosystems reaching a critical threshold of permanent damage.
How can ocean acidification be exacerbated?
- global warming
- tropical storms
- pollution
How does ocean acidification cause coral bleaching?
The acid in the water dissolves carbonate shells.
What implications have climate change had on the Amazon?
- more extreme cycles of droughts and flood
- decreased rainfall in deforested areas
What are examples of services provided by trees?
- nutrient cycling
- soil formation
- primary production
- water purification
- regulating climate
- flood defence
- cultural values
What are examples of goods provided by trees?
- food
- wood/fibre
- fuel
Why has the net loss of forests reduced?
afforestation
What does Kuznet’s curve suggest?
The communities reach a tipping point where exploitation of forests changes to more protection.
What factors may affect a country’s decision to protect forests?
- wealth
- increasing knowledge of benefits
- environmental laws
- involvement of locals
- power/influence of TNCs
What percentage of forests are classed as conserved
18%
What impacts can global warming have on the hydrological cycle?
Changing precipation patterns, river regimes and water stores
What impact has changing global climate had on the Arctic?
- loss of ice sheets
- shrinking glaciers
- loss of albedo effect
What threats does global warming have to oceans?
- bleaching
- acidification
- rising sea levels
- loss of sea ice
Why is ocean life important?
- all countries eat/sell/buy fish
- coral reefs protect areas from waves
- coral reefs attract tourists
- millions rely of fishing for income
- loss of livelihoods if fish die
What are examples of uncertainties about natural factors for future global warming?
- the role of carbon sinks and their capacity to cope
- possible feedback mechanisms
- tipping points
What are examples of uncertainties about human factors for future global warming?
- futural global economic and population growth rates
- planned reduction in global carbon emissions
- exploitation of renewable ergy sources
What may future changes to terrestrial carbon sinks look like with increasing carbon emissions?
- An overall increase in terrestrial carbon stores until 2050.
THEN: - thawing of permafrost
- boreal forests shift north
- tropical rainforests reduce storage as capacity is reached
What may changes to oceanic carbon sinks look like with increasing carbon emissions?
- increased store in sea grasses/algae
- Tropical oceans become warmer so absorb less carbon.
- Decreasing efficiency and slowing down of biological pump.
