Global warming and human activity: A model for studying the potential instability of the carbon dioxide/temperature feedback mechanism

In this paper, control theory is used to study the connection between human activities and global warming. A feedback model is proposed and tested against temperature and carbon dioxide concentration historical data. Four scenarios are taken into account and simulated by the model; stability analysis is also discussed. The model proposed here simulates the historical data correctly and the scenarios show that, even in the case of dramatic reduction of the anthropogenic carbon dioxide emission, the temperature will not decrease for a certain time. Stability analysis reveals a complex pole near the unit circle. This means that, although the system at the moment is stable, it is very close to becoming unstable with unpredictable consequences on climate change. (C) 2006 Elsevier B.V. All rights reserved.