Stabilization of Atmospheric Greenhouse Gases: Physical, Biological and Socio-economic Implications

An understanding of the constraints on the stabilization of greenhouse gas concentrations is fundamental to policy formulation with regard to the goals of the United Nations Framework Convention on Climate Change and its implementation. This Technical Paper provides:

(a) A tutorial on the stabilization of greenhouse gases, the estimation of radiative forcing, and the concept of “equivalent carbon dioxide (CO2)” (the concentration of CO2 that leads to global mean radiative forcing consistent with projected increases in all gases when a suite of gases is being considered);

(b) A basic set of CO2 stabilization profiles leading, via two types of pathway, to stabilization between 350 and 750 ppmv, with a single profile stabilizing at 1 000 ppmv;

(c) The deduced emissions for the aforementioned concentration stabilization profiles;

(d) A consideration of the stabilization of radiative forcing agents other than CO2

(e) Global mean temperature and sea level changes for the CO2 profiles using a range of emissions assumptions for methane (CH4), nitrous oxide (N2O) and sulphur dioxide (SO2), and different values of the climate sensitivity and ice-melt model parameter values in order to characterize uncertainties;

(f) A discussion of the potential environmental consequences of the derived changes in temperature and sea level;

(g) A discussion of the factors that influence mitigation costs; and

(h) A review of the methodology for integrating climate and sea level change effects and mitigation costs to produce a more complete view of the consequences of changing atmospheric composition.