Unformatted text preview: Earth is a system open to the sun’s radiation • About 6000K taken into the earth • 300K are emitted o Ecosystems are self sustaining with only sun rays as the only input It takes a forest 120 years to achieve this stability • At stability, the ecosystem is most evolved • Then fires occur to restart the cycle • Little fires are good, big fires will cause extinction But a microcosm can do it in 120 days o China For 4000 years has been engaged in sustainable agriculture • They recycled everything o Solar power is significantly more efficient than agri-fuels systems o Lecture # 1 of 1 #/#/07 Written By Raymond Leung...
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This note was uploaded on 04/02/2008 for the course CE 70 taught by Professor Johnson during the Fall '07 term at Berkeley.
- Fall '07
- Civil Engineering