Estimated major stores of carbon on the Earth

5.2.1 The Carbon CycleCarbon exists in many forms:

•Atmospheric gases (CO2 and

methane)

•Dissolved CO2 in aquatic

ecosystems

•Organic carbon in living

organisms

•Carbon deposits in the

lithosphere, as minerals

(carbonates) or fossil fuels.What are the sources of atmospheric CO2?

What is the sink of atmospheric CO2?

Which processes return C to the lithosphere?

Respiration, Decomposition, Diffusion, burning of fossil fuels (combustion)

Producers and fossil fuels - photosynthesis, some diffusion into aquatic systems

Decomposition of organic matter, marine deposits of carbonates

5.2.1 The Carbon Cycle

5.2.2 Analyse the change in concentration of atmospheric CO2 using historical records

5.2.2 Analyse the change in concentration of atmospheric CO2 using historical records

These measurements indicate a rise in annual average atmospheric CO2 concentrations, from 354.07 parts per million by volume (ppmv) in 1992 to 378.50 ppmv in 2006, or an increase of almost 1.75 ppmv per year, on average.

5.2.3 Relationship between CO2 and other gases and the enhanced greenhouse effect

5.2.3 Relationship between CO2 and other gases and the enhanced greenhouse effect

Elevated levels of greenhouse gases are strongly correlated with an enhanced

greenhouse effect:

Although we see correlation, where do scientist find the evidence for a causal relationship?

As levels of CO2, methane, water

vapour and oxides of nitrogen

increase, more radiation is reflected

back to Earth instead of being lost to

space.

5.2.3 Relationship between CO2 and other gases and the enhanced greenhouse effect.

5.2.3 Relationship between CO2 and other gases and the enhanced greenhouse effect.

Which gases in the table have the potential to cause the most damage?

5.2.4 Outline the precautionary principle

5.2.5 Evaluate the precautionary principle

5.2.6 Consequences of a global temperature rise on arctic ecosystems.

•Increased rates of decomposition of detritus previously trapped in

permafrost,

•Expansion of the range of habitats available to

•Temperate species,

•Loss of ice habitat,

•Changes in distribution of prey species affecting higher trophic levels

•Increased success of pest species, including pathogens