EQ3: How are the carbon and water cycles linked to the global climate system?

6.7 Biological carbon cycles and the water cycle are threatened by human activity

Explain why growing demand for food, fuel and other resources globally has led to contrasting regional trends in land-use cover (deforestation, afforestation, conversion of grasslands to farming) which affect terrestrial carbon stores and subsequently the water cycle and soil health.

Explain how ocean acidification, is increasing due to fossil fuel combustion and is at risks crossing the critical threshold for the health of coral reefs and other marine ecosystems that provide vital ecosystem services

Explain how climate change, resulting from the enhanced greenhouse effect, may increase the frequency of drought due to shifting climate belts, which may impact on the health of forests as carbon stores.

6.8 There are implications for human wellbeing from the degradation of the water and carbon cycles

Explain how forest losses has implications for human wellbeing but that there is also evidence that forest stores are being protected and even expanded, especially in countries at higher levels of development (environmental Kuznets' curve model).

Explain how increased temperatures affect evaporation rates and the quantity of water vapour in the atmosphere with implications for precipitation patterns, river regimes and water stores (cryosphere and drainage basin stores).

Explain why threats to ocean health pose threats to human wellbeing, especially in developing regions that depend on marine resources as a food source and for tourism and coastal protection.

6.9 Further planetary warming risks large-scale release of stored carbon, requiring responses from different players at different scales

Explain why future emissions, atmospheric concentration levels and climate warming are uncertain owing to natural factors, human factors and feedback mechanisms

Analyse the adaptation strategies for a changed climate (water conservation and management, resilient agricultural systems, land-use planning, flood-risk management, solar radiation management) and explain the different costs and risks.

Explain how re-balancing of the carbon cycle could be achieved through mitigation and why this requires global scale agreement and national actions both of which have proved to be problematic..