The Carbon Cycle and Energy Security
Contents
Terrestrial Carbon Stores.......................................................................................................................1
Biological Processes Sequestering Carbon.............................................................................................7
Human Interference in the Carbon Cycle.............................................................................................13
Energy Security....................................................................................................................................16
Reliance on Fossil Fuels.......................................................................................................................20
Alternatives to Fossil Fuels..................................................................................................................25
The Threat of Human Activity..............................................................................................................28
The Implications for Human Wellbeing...............................................................................................31
Responses to Risks of Further Planetary Warming..............................................................................36
Terrestrial Carbon Stores
Cycles, Stores & Fluxes
carbon cycle
o biogeochemical cycle by which carbon moves from sphere to another
o acts as a closed system made up of linked subsystems that have inputs, throughputs
and outputs
o carbon stores function as sources(adding carbon to atmosphere) and sinks
(removing carbon from atmosphere)
carbon is the main building block of life
present in the stores of
o atmosphere – CO2 & methane
o hydrosphere – dissolved CO2
o lithosphere – carbonates in limestone & fossil fuels (col, oil, gas)
o biosphere - in living and dead organisms
carbon moves from one sphere to another by linked processes known as the biogeochemical
carbon cycle
complete decomposition of organic matter results in carbon returning to inorganic forms
e.g. CO2 and carbonates contained in rock and seawater
processes including photosynthesis and diffusion drive the flows or fluxes between the
stores
if sources equal sinks the carbon cycle is balanced or in equilibrium
o no change in the size of stores
changes in the system may result in positive or negative feedback
one of the most important drivers of the carbon cycle is the water cycle
Page 1 of 41
The Carbon Cycle and Energy Security
Contents
Terrestrial Carbon Stores.......................................................................................................................1
Biological Processes Sequestering Carbon.............................................................................................7
Human Interference in the Carbon Cycle.............................................................................................13
Energy Security....................................................................................................................................16
Reliance on Fossil Fuels.......................................................................................................................20
Alternatives to Fossil Fuels..................................................................................................................25
The Threat of Human Activity..............................................................................................................28
The Implications for Human Wellbeing...............................................................................................31
Responses to Risks of Further Planetary Warming..............................................................................36
Terrestrial Carbon Stores
Cycles, Stores & Fluxes
carbon cycle
o biogeochemical cycle by which carbon moves from sphere to another
o acts as a closed system made up of linked subsystems that have inputs, throughputs
and outputs
o carbon stores function as sources(adding carbon to atmosphere) and sinks
(removing carbon from atmosphere)
carbon is the main building block of life
present in the stores of
o atmosphere – CO2 & methane
o hydrosphere – dissolved CO2
o lithosphere – carbonates in limestone & fossil fuels (col, oil, gas)
o biosphere - in living and dead organisms
carbon moves from one sphere to another by linked processes known as the biogeochemical
carbon cycle
complete decomposition of organic matter results in carbon returning to inorganic forms
e.g. CO2 and carbonates contained in rock and seawater
processes including photosynthesis and diffusion drive the flows or fluxes between the
stores
if sources equal sinks the carbon cycle is balanced or in equilibrium
o no change in the size of stores
changes in the system may result in positive or negative feedback
one of the most important drivers of the carbon cycle is the water cycle
Page 1 of 41
The Carbon Cycle and Energy Security
