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Originally Posted by Pinner
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That doesn't answer the question that was asked.
Plus the graph is easy to misunderstand without context. Water vapor is very easy to take out of the atmosphere, it happens all the time (rain, snow, condensation, etc). CO2 not so much, it'll stay there for years or even centuries if nothing else pulls it out.
Plus water vapor creates a positive feedback, magnifying the result of smaller things.. a little more CO2 results in warming, which results in more water vapor possible to be in the air, which results in more warming, etc.. positive feedback.
Quote:
Originally Posted by Delthefunky
What percentage do our CO2 emmisions add to the natural release of CO2 (Russian ice pocket, volcanoes, forest fires)?
Honest question...
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The total carbon cycle is something like 750 gigatons per year, human emissions are in the order of 30 gigatons per year. So it's smaller obviously but still significant because the CO2 from the plants and animals and the ocean also gets reabsorbed by the same, everything in a balance with feedbacks to keep it there (otherwise life would have CO2'd itself to death long long ago). The CO2 from fossil fuels gets put out, but there's no natural balance. 40% of the CO2 gets absorbed (the ocean has become more acid as a result), but the rest just sits there. So 30 gigatons is < 750 gigatons, but it's cumulative.
And we know it's from fossil fuels, since you can measure the isotopes of carbon in atmospheric CO2 and compare those to ratios of isotopes in various sources.