Solar input |
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The sun is earth’s only external energy source, with an average power of 341.5 W/m2, spanning between zero at night and over the poles, and 1366 at the equatorial maximum. |
Annual precipitations | ||||||||||||||||||||
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Human energy production | ||||||||
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Biomass production |
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For a field or a forest producing 30 metric tons of biomass per hectare and year with a heating value of 18'000 KJ/Kg (= 5 KWh/Kg): Biomass growth is not constrained by the solar energy input but by the plant genetics, competition for space (in the soil and above ground), the rate of absorption and the quantity of available nutrients (with the Liebig limiting factor of the least abundant of N, P or K), irrigation, and, last but not least, the concentration of atmospheric CO2 to engage photosynthesis. |
Carbon emissions |
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Since the beginning of the industrial era (BIE), 385 Pg (petagram, or gigaton) of carbon have been emitted into the atmosphere in the form of carbon dioxide (CO2). The current emissions are 10 Pg carbon per year. The atmospheric CO2 concentration was approx. 280 ppm before the beginning of industrial era (BIE). From all emitted carbon since BIE, approx. 66 % remained in the atmosphere, the other 34 % were absorbed to form additional biomass on land or in the seas, to be absorbed by the oceans, and to be mineralized. |
Glacier, ice sheets |
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Most, but not all, glaciers are melting. |
Global temperature rise without climate "victims" |
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In nature these temperature changes make themselves noticeable by earlier crop maturity and by the migration of some insect and plant species from South to North (in the Northern Hemisphere). |