Wednesday, February 6th 2013, 9:23 AM EST
An important new paper published today in Global Biogeochemical Cycles finds that "In contrast to recent claims, trends in the airborne fraction of anthropogenic carbon [dioxide] cannot be detected when accounting for the decadal-scale influence of explosive volcanism and related uncertainties." In other words, after accounting for the large effect of volcanic eruptions, ENSO, and other uncertainties upon natural CO2 sinks, trends in the man-made fraction of atmospheric CO2 "cannot be detected." Thus, despite an exponential increase in man-made CO2 emissions, there is no statistically significant trend in the man-made fraction of CO2 in the atmosphere.
This further suggests that man is not the primary cause of the increase of CO2 in the atmosphere, that temperature is responsible for the increase in CO2 levels due to out-gassing. According to the authors, "Our results highlight the importance of considering the role of natural variability in the carbon cycle for interpretation of observations and for data-model intercomparison."
Note man-made emissions are only about 4% of the total CO2 emissions in the atmosphere, and CO2 only represents about 0.04% of the entire atmosphere
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