y H to space The Organic Carbon (and oxygen) Cycles Photolysis of water Atmosphe
ID: 289057 • Letter: Y
Question
y H to space The Organic Carbon (and oxygen) Cycles Photolysis of water Atmosphere 3.8 x 1019 moles 02 7 x 109 moles yr of O2 7.3 x 1016 moles CO Energy production 3 x 104 moles yr Weathering 1013 moles yr-1. Respiration and decay Photosynthesis 106 moles yr 1016 moles yr Surface organic matter 2 x 1017 moles C Burial 1013 moles yr Reservoirs O Processes Feedbacks Sedimentary rocks 101 moles Con Fossil fuels Corg + O2 = CO2 6-10" moles c | CO2 + H2O = "CH20" + o. Fig. 31. Processes (circles) and reservoirs (boxes) affecting the oxygen content of the atmosphere. (From Walker, 1974. Copyright 1974 by the American Journal of Science. New Haven. Conn. Used by permission of the publisher.) at 400 ppmvExplanation / Answer
2) The earth's entire reservoir of fossil fuels as shown in the diagram, Vff = 6*1017 moles
Also, as shown in the diagram, the energy production consumes carbon at a rate of 3*1014 moles/yr
Therefore, the time required to consume all the fossil fuels = 6*1017 / 3*1014 = 2000 years
3) If we burn Earth's entire reservoir of fossil fuels i.e., 6*1017 moles of Carbon instantaneously, the same amount of oxygen will be deducted from the Earth's atmosphere. This is because for every mole of carbon burnt the same amount of O2 will be consumed to form CO2. Therefore, the amount of O2 remaining in the Earth's atmosphere if we burn all the fossil fuels is,
Atmospheric O2 = 3.8*1019 - 6*1017 = 380*1017- 6*1017 = 374*1017 = 3.74*1019 moles O2
The percentage depletion of the oxygen would be = (3.8*1019 - 3.74*1019) / 3.8*1019 = 1.58%
Therefore, yes burning the entire fossil fuel instantaneously would reduce the atmospheric oxygen by 1.58% which is a significant change in a short period of time. Such instantaneous change will impact the atmospheric stability and will impact numerous species that consume oxygen for respiration as well as photosynthesis. The net primary productivity of ecosystems would come down and will impact ecosystem resilience too.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.