• We present a carbon cycle with an uptake proportional to the CO2 concentration.
• Temperature dependent natural emission and absorption rates are considered.
• The average residence time of CO2 in the atmosphere is found to be 4 years.
• Paleoclimatic CO2 variations and the actual CO2 growth rate are well reproduced.
• Human emissions only contribute 15 % to the CO2 increase over the Industrial
Climate scientists presume that the carbon cycle has come out of balance due to the
increasing anthropogenic emissions from fossil fuel combustion and land use change.
This is made responsible for the rapidly increasing atmospheric CO2 concentrations
over recent years, and it is estimated that the removal of the additional emissions
from the atmosphere will take a few hundred thousand years. Since this goes along
with an increasing greenhouse effect and a further global warming, a better understanding
of the carbon cycle is of great importance for all future climate change predictions.
We have critically scrutinized this cycle and present an alternative concept, for
which the uptake of CO2 by natural sinks scales proportional with the CO2 concentration.
In addition, we consider temperature dependent natural emission and absorption rates,
by which the paleoclimatic CO2 variations and the actual CO2 growth rate can well
be explained. The anthropogenic contribution to the actual CO2 concentration is found
to be 4.3%, its fraction to the CO2 increase over the Industrial Era is 15% and the
average residence time 4 years (emphasis added)