carbon Flashcards
geological carbon cycle
-natural cycle that moves between land,oceans and atmosphere
-involves a number of chemical reactions that create new stores that trap carbon for significant periods of time
out gassing
terrestial carbon, held within the mantle, is released into the atmopshere as carbon dioxide when volcanos erupt.
chemical weathering
co2 in the atmosphere combines with rainfall to produce a weak acid that dissolves carbonate rich rocks releasing bi carbonate.
4 key proccesses to the bio chemical carbon cycle
-photosynthesis
-respiration
-decomposition
-combustion
what are the three forms of carbon
-inorganic- rocks as bicarbonates/carbonates
-organic- plant material
-gaseous- found as co2,methane and carbon monoxide
the biological carbon pump
-100 million tonnes moved through this cycle
-an exchange of carbon dioxide; some is dissolves into the water and some is vented out into the air above
-the ocean contains phyoplankton which have shells that sequester (through photosynthesis) co2 creating calcium carbonate , when they die they sink to the ocean floor and accumalte sediment.
-this is important as it plays a huge role in pumping co2 out of the atmosphere into the ocean
-slight chnages in temperature or light or pollution can alter the flow, making it a fragile system
the role of trees
-95% of trees biomass is made from co2
-carbon fixation turn gaseous carbon into organic compounds that grow
-leaf litter decomposes and releases carbon
-trees sequest carbon during photosynthesis
-plant respiration releases carbon
mangroves and role of soil
-found along the tropical and sub tropical tidal coasts in africa, australia,asia and the americas
-sequest 1.5 million tonnes of carbon per hectare a year
-mangrove soil consists of thick organic layers of litter,humus and peat containing mass amounts of carbon
-the soils are anerobic allowing them to respire without oxygen producing co2 when submergered
tundra soils
-permantly frozen and contains ancient carbon
-thawing releases all microbes and carbon once stored
the enhanced greenhouse effect
-the concentrations of several greenhouse gases in the atmosphere have increased by 25% since 1750,when industrialisation has started.
-since the 1980s 75% of co2 emissions have come from the burning of fossil fuels
-this lead to an increase in global temperatures leading to an enhanced green house effect
artic amplification
-the artic is warming twice as fast as the global average
-melting permafrost releases co2 and ch4 increasing the concentration of these gases into the atmosphere, leading to a global increase in temperature and further melting
-rapid warming contributes to extensive melting of sea ice aswell as greatly reduced snow cover
urban consumption - london
-city of london generates 1.7 million tonnes of carbon per year, with residents averaging 1.8 tonnes of carbon per capita
-cities consume 75% of the worlds energy and produce 80% of the worlds carbon emissions
