2. Estimated major stores of carbon on the Earth 5.2.1 The Carbon Cycle Carbon exists in many forms: Atmospheric gases (CO 2 and methane) Dissolved CO 2 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 CO 2 ? What is the sink of atmospheric CO 2 ? 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

3. 5.2.1 The Carbon Cycle

4. 5.2.2 Analyse the change in concentration of atmospheric CO 2 using historical records

5. These measurements indicate a rise in annual average atmospheric CO 2 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.

6. 5.2.3 Relationship between CO 2 and other gases and the enhanced greenhouse effect

7. 5.2.3 Relationship between CO 2 and other gases and the enhanced greenhouse effect

8. 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 CO 2, 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 CO 2 and other gases and the enhanced greenhouse effect.

9. 5.2.3 Relationship between CO 2 and other gases and the enhanced greenhouse effect. Which gases in the table have the potential to cause the most damage?

10. 5.2.4 Outline the precautionary principle

11. 5.2.5 Evaluate the precautionary principle

13. 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