4.a. The two cycles are linked and interdependent

Question 1

How do human activites cause change in carbon stores

Answer 1

• rapid population, economic growth, deforeststation and urbanisation- modified size carbon cycle+rates of flux between stores
• human activity depleting some carbon stores+increasing others
• deforestation- reduced the plants forest cover by nearly 50%- carbon stored by biosphere in steep delince
• deforestation and agricultural mismanagement leading to soil erosion- reducing ability to hold carbon
• wetlands drained for cultivation and urban development, removing their ability to store carbon

Question 2

Statistic- carbon stored in above ground biomass after 10 years after deforestation

Answer 2

• 180

- 10 years- 43

Question 3

How has climate change affected carbon cycle

Answer 3

• higher temperatures increase rates of decomposition
• carbon frozen in permafrost released as temperature rises- allows oxidation and decomposition of vast peat stores
• increasing ocean aciditiy levels lead to reduction in rate of photosynthesis by phytoplankton, increasing oceans capacity