water and carbon linked? Flashcards
water and carbon linked in atmosphere
atmospheric CO2 has a greenhouse effect
CO2 vital in photosynthesis by plants and phytoplankton
plants store carbon and extract water from the soil and transpire it as part of the water cycle
water evaporated from from oceans to atmosphere and CO2 is also exchanges between the two stores
water and carbon linked in oceans
ocean acidity icnreases when exchanges of CO2 are not balanced
solubility of CO2 in the oceans increases with lower SSTs
Atmospheric CO2 levels influence and the thermal expansion of the oceans, air temps, melting of ice sheets …
water and carbon linked in vegetation and soil
water availability influences rates of photosynthesis, NNP, inputs of organic litter to soils and transpiration
water storage of soils increases with organic content
temps and rainfall effect decomposition rates and the release of CO2 to the atmosphere
water and carbon linked in cryosphere
CO2 levels in the atmosphere determine intensity of greenhouse effect and melting of ice sheets…
melting exposes land and sea surfaces which more solar radiation and raise temps further
permafrost melting exposes organic material to oxidation and decomposition which releases CO2 CH4
run off, river flow and evaporation all respondent to temp
how has human activity effected the water cycle?
rising demand for agriculture, irrigation and public supply has created shortages which can be seen in rivers and aquifers
eg Colorado basin in USA has diminished as water is extracted from
how has human activity effected the carbon cycle?
reliant on fossi fuels
rapid industrialisation across the world in the last 30 years has made worse
1 billion tonnes emitted annually
deforestation
what is the impact of long term climate change on the water cycle?
more vapour atmosphere increases global temp, increasing evaporation and precipitation
higher run off and greater flood risks
vapour is a source of energy in the atmosphere releasing latent heat on condensation
extreme weather events will become more frequent
what is the impact of long term climate change on the carbon cycle?
change is dependent on rising temps and rainfall variations
increase rates of decomposition = accelerating rates of carbon transfers from biosphere to atmosphere
humid tropics climate change increases aridity and threatens the existence of forests and are replaced by grasslands
carbon stored diminishes
carbon frozen in permafrost released and peat stores oxidise and decompose
oceans are acidified
long term= more CO2 stored in atmosphere and less in oceans and biosphere
what is a wetland?
area where the water table is at or near the surface causing the ground to be permanently saturated
marshes, floodplains…
why do wetlands need to be restored?
urbanisation has places huge pressure on wetlands
in US, wetland area has halved since 1600
loss of biodiversity and habitats
why are wetlands important?
can store 3.25 tonnes C/ha per year
in Canada 112,000 ha targeted for restoration which should eventually sequester 364,000 c/ha/ year
what initiatives are helping restore wetlands?
International Convention on Wetlands
European Union Habitats Directive
Cambridgeshire is currently being restored to wetland
UK government wanted to meet restore 500ha of wetland by 2020
how are they going to restore wetlands?
raise water tables to recreate water logged conditions
removing flood embankments
breaching sea defences
diverting or blocking drainage ditches and installing sluice gates
what is afforestation?
plating trees in deforested areas or areas that have never been forested
why is afforestation beneficial?
can help reduce atmospheric CO2 in the medium to long term
reduces flood risk and soil erosion