ENV100H1 Lecture Notes - Lecture 13: David Schindler, Crop Rotation, Water Cycle

• School: UTSG
• Department: School of Environment
• Course: ENV100H1
• Professor: Barbara Murck

Document Summary

How carbon dioxide in the atmosphere has fluctuated in earth"s history. Flux rate into the atmosphere has changed over time. Size of the carbon reservoir was different during the geological history of the earth. 110-90 mya co2 levels were 4 times higher than they were today. We will not survive in a cretaceous earth. Mean global temp was 6. 2 degrees higher than today caused by rapid sea floor spreading: new crust being formed which released a lot of co2 no glacial ice caps. When we talk about the carbon cycle, it functions on a whole bunch of temporal scales dramatic change in the flux of carbon in history. Humans affect the carbon cycle carbon mobilization: burning fossil fuels geosphere atmosphere, deforestation, burning of biomass biosphere atmosphere, cattle and rice production biosphere atmosphere. Cattle contribute an enormous amount to greenhouse gases. Methane is a very potent greenhouse gas. Livestock produce 18% of greenhouse gases: more than the transportation sector.