What Humans Contribute to Atmospheric CO 2 : 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.