This is a companion to DOI:10.1029/2005GL025540.
Positive feedback between global warming and atmospheric CO2 concentration inferred from past climate change
Article first published online: 26 MAY 2006
Copyright 2006 by the American Geophysical Union.
Geophysical Research Letters
Volume 33, Issue 10, May 2006
How to Cite
2006), Positive feedback between global warming and atmospheric CO2 concentration inferred from past climate change, Geophys. Res. Lett., 33, L10702, doi:10.1029/2005GL025044., , and (
- Issue published online: 26 MAY 2006
- Article first published online: 26 MAY 2006
- Manuscript Accepted: 14 FEB 2006
- Manuscript Revised: 9 JAN 2006
- Manuscript Received: 25 OCT 2005
 There is good evidence that higher global temperatures will promote a rise of greenhouse gas levels, implying a positive feedback which will increase the effect of anthropogenic emissions on global temperatures. However, the magnitude of this effect predicted by the available models remains highly uncertain, due to the accumulation of uncertainties in the processes thought to be involved. Here we present an alternative way of estimating the magnitude of the feedback effect based on reconstructed past changes. Linking this information with the mid-range Intergovernmental Panel on Climate Change estimation of the greenhouse gas effect on temperature we suggest that the feedback of global temperature on atmospheric CO2 will promote warming by an extra 15–78% on a century-scale. This estimate may be conservative as we did not account for synergistic effects of likely temperature moderated increase in other greenhouse gases. Our semi-empirical approach independently supports process based simulations suggesting that feedback may cause a considerable boost in warming.