What Humans Contribute to Atmospheric CO<sub>2</sub>: Comparison of Carbon Cycle Models with Observations

Abstract

The Intergovernmental Panel on Climate Change assumes that the inclining atmospheric CO 2 concentration over recent years was almost exclusively determined by anthropogenic emissions, and this increase is made responsible for the rising temperature over the Industrial Era. Due to the far reaching consequences of this assertion, in this contribution we critically scrutinize different carbon cycle models and compare them with observations. We further contrast them with an alternative concept, which also includes temperature dependent natural emission and absorption with an uptake rate scaling proportional with the CO 2 concentration. We show that this approach is in agreement with all observations, and under this premise not really human activities are responsible for the observed CO 2 increase and the expected temperature rise in the atmosphere, but just opposite the temperature itself dominantly controls the CO 2 increase. Therefore, not CO 2 but primarily native impacts are responsible for any observed climate changes.

Human CO<sub>2</sub> Emissions Have Little Effect on Atmospheric CO<sub>2</sub>

“…Equation 12shows the percentage of human-produced CO 2 in the atmosphere equals its percentage of its inflow, independent of e-time. Equations 9and (10) support the key conclusions of Harde [24,25]:…”

“…Authors who support the USGCRP [1] and IPCC [2,3] include Archer et al [4], Cawley [5], Kern and Leuenberger [6], and Kohler [7]. Authors who conclude human CO 2 increases atmospheric CO 2 as a percentage of its inflow include Revelle and Suess [8], Starr [9], Segalstad [10], Jaworoski [11,12], Beck [13], Rorsch, Courtney, and Thoenes [14], Courtney [15], Quirk [16], Essenhigh [17], Glassman [18], Salby [19][20][21][22], Humlum [23], Harde [24,25], and Berry [26,27].…”

How Much Human-Caused Global Warming Should We Expect with Business-As-Usual (BAU) Climate Policies? A Semi-Empirical Assessment

“…The annual changes in atmospheric concentrations show quite a lot of variability from year-to-year, which is not apparent from the annual anthropogenic emissions, and the airborne fraction actually varies quite a bit from year-to-year, as has been noted by others (e.g., refs. [74][75][76][77][78][79][80][81][82]). This suggests that natural variability actually plays quite a substantial role in atmospheric CO 2 concentration trends.…”

“…Moreover, if it were to transpire that all (or even most) of the recent increase in atmospheric CO 2 were a natural phenomenon, then this would completely undermine the entire basis for claiming that society's CO 2 emissions are causing "human-caused global warming". Therefore, whenever a researcher publishes an analysis suggesting that some or all of the recent increase could be natural in origin, such as the references cited above [76,[78][79][80][81][82] and also refs. [74,75,77,[83][84][85][86][87][88][89], their arguments are attacked with a particular vehemence, e.g., [90][91][92][93][94][95][96][97][98][99].…”

“…For this reason, several researchers have argued that some component of the observed increase in atmospheric CO 2 since 1959 could be a result of a natural global warming trend (i.e., the opposite of the human-caused global warming theory), e.g., refs. [16,17,74,75,77,[79][80][81]85,113]. Importantly, this paradigm does not rule out a contribution from anthropogenic emissions in the recent increase-rather, anthropogenic emissions are treated as an additional source that needs to be taken into account.…”