Integrated Assessment Modeling (IAM)

IAM and Analysis

Over the last recent years, AIMES’s Integrated Assessment Modeling activity helped initiate and support development of the Representative Concentration Pathways (RCPs), a set of four new pathways developed with the climate modeling community as a basis for long-term and near-term modeling experiments in support of the IPCC. The approach evolved out of a workshop, held in Aspen, Colorado and sponsored by AIMES and the Aspen Global Change Institute (Hibbard et al 2007).  The four RCPs together span the range of year 2100 radiative forcing values (in contrast to traditional emission-oriented scenarios) found in the open literature, i.e. from 2.6 to 8.5 W/m2. Rather than projecting a socio-economic storyline, the RCPs span a range of likely future climate forcings and can be analyzed both in terms of 1) the climate impact and carbon cycle consistent with a given radiative forcing, and 2) multiple socio-economic story lines that could lead to that degree of radiative forcing and so are far less prescriptive and controversial than the prior IPCC approach.   The RCPs are the product of an innovative collaboration between social scientists, including integrated assessment experts, climate modelers, terrestrial ecosystem modelers and emission inventory experts. The resulting product forms a comprehensive data set with high spatial and sectoral resolution for the period extending to 2100.  The underlying integrated assessment model outputs for land use, atmospheric emissions and concentration data consistent with the different radiative forcing scenarios were harmonized across models and scenarios to ensure consistency with historical observations while preserving individual scenario trends. The RCPs are an important development in climate research and are the foundation for a great deal of research and assessment, including emissions mitigation and climate impact analysis.

Integrated Modelling of Human and Environmental Systems