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Computare
Carbon Cycle Summary
•Humans control much of carbon cycle
–24 billion tonnes of plant production
–Fossil fuels 6 billion tonnes
•Opportunity
–Integrate energy use with carbon control
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Consideration  of the carbon cycle raises some fundamental questions. Does division of the cycle into “human” and “natural” components tend to excessively  focus on   fossil fuel use as the “problem”?  There is reason to think so.
A recent paper addressed human  influence on climate through the development of agriculture. The author concluded humans began to influence climate nearly 8000 years ago.
Humans cultivate 10 to 15% of land – and we control forests. We appropriate about 40% of plant production.
 It follows that we are responsible for 24 billion tonnes of the 60 billion tonnes of carbon absorbed by plants annually. Contrast that with the 6 billion tonnes from fossil fuels.
Thinking about the carbon cycle suggests opportunities to better integrate our energy use with management of carbon.
Let’s consider some examples.