20 terms

Human and Physical factors affecting the Carbon Cycle

Physical factors
Those natural factors that can affect the carbon cycle such as volcanic acivity
Human factors
The actions of people and their impact upon the carbon cycle such as agriculture, deforestation and burning fossil fuels
Ocean Carbon Pumps
CO2 can dissolve into ocean water, this carbon sinks towards the bottom of the ocean at high latitudes as it cools down, and rises to the surface at low latitudes as it warms.
Vertical deep mixing
Part of the ocean carbon pump, process where ocean water drags carbon down to the deep oceans in cold high latitudes and carries it up to the surface in lower latitudes where it can be released into the atmosphere
Biological pump
living things in the ocean like phytoplankton help to move carbon from the ocean surface waters into the deeper waters and eventually sequester into sedimentary rocks.
sea creatures make their shells from calcium carbonate. When they die these shells and their tissues sink to the ocean bed where it forms carbon rich sediments. These sediments can be transformed into rocks such as Limestone
occurs when any organic material is burned or reacted in the presence of oxygen to give off water, energy and carbon dioxide.
Biomass combustion
simply means burning organic material, can occur because of human activity but also natural wild fires often caused by a build-up of dry leaf litter and lightning strikes.
Forest fire carbon balance
is complex as some trees are brunt and die releasing carbon, but some of that is released into and stored in soils, and other new trees grow absorbing carbon.
3 to 4 million km squared
amount of the Earth's surface that is burnt by forest fires every year releasing over a billion tonnes of CO2
Volcanic activity and global warming
no discernible relationship as any carbon emitted by volcanic eruptions seems to be counterbalanced by emissions of sulphur dioxide which mixes with water in the atmosphere and increases reflection of sunlight back out to space
Fossil fuels
a natural fuel such as coal or gas, formed in the geological past from the remains of living organisms in anoxic environments. Carbon stores.
Land Use changes
Account for up to 30% of carbon emissions from human activity
Soil ploughing
Increases the emissions of carbon into the atmosphere: as the soil layers invert due to ploughing air mixes in allowing more decomposition to occur
Enteric Fermentation
A digestive process by which carbohydrates are broken down by microorganisms into simple molecules for absorption into the bloodstream of an animal. Releases Methane as a waste gas which is significant due to the farming of animals
Rice paddies
generate 10% of all agricultural methane emissions
Hydrocarbon extraction and burning
is the major cause of global warming, as oil, gas and coal are burned releasing stored carbon
Cement manufacture
Releases CO2 when the calcium carbonate is heated producing lime and CO2 which is released into the atmosphere
is driven mainly by the need for farmland, releases huge amounts of carbon and interferes with the water cycle
Urban growth
Can increase carbon emissions through the conversion of natural vegetation to urban areas, the production of concrete and the CO2 emitting activities that occur in there.