A DYNAMIC SIMULATION MODEL OF CARBON CIRCULATION AND METHANE FEEDBACKS IN ANTHROPOGENIC CLIMATE CHANGE

摘要

The human induced climate change is one of the most serious and difficult environmental issue to manage that has emerged in the recent decades. Although the severity of the problem and the need for urgent action are unquestionable today, people usually prefer 'wait and sec' policies instead of prompt action. One reason of this tendency is inherent difficulties of understanding the dynamics of anthropogenic climate change and anticipating the possible future results of today's actions. Climate change is a good example of a dynamic systems problem. It embodies several delays, feedbacks, nonlinearities and uncertainties in its dynamically complex structure. Therefore, the need for and the usefulness of descriptive and simple models explaining these dynamic complexities are undisputed. The aim of this study is to construct a dynamic simulation model for this end. The model integrates several components of the climate system. It includes the carbon cycle, radiative forcing of CO_2, CH_4, N_2O and induced temperature change as well as the temperature feedback affecting carbon exchange between land and the atmosphere. It also proposes a representation of the permafrost melting and methane feedback processes. The model aims at enabling the user to test the effects of these feedbacks, the emission scenarios and parameter uncertainty on greenhouse gas concentrations and related temperature change. Model structure is validated with indirect structure tests. Historical emissions and temperature change data are used to calibrate the model behavior. For future work, we aim to transform the model to an interactive learning environment that can be reached from the web to be used by the general public so as to improve their understanding of the dynamics of anthropogenic climate change.