Executive Summary

• Main Authors: Gerald A. Meehl, Kathy Hibbard
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2006
• Subjects: Sea ice
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.417.6600; http://www.agci.org/dB/PDFs/06S1_ExecutiveSummary.pdf

It has been recognized that we are now on the threshold of including earth system model (ESM) components in “standard ” global coupled climate models used for climate change projections. At present, these standard models (referred to generically at atmosphere-ocean general circulation models or AOGCMs) include components of atmosphere, ocean, land, sea ice. New candidate components for inclusion in these models include carbon cycle, aerosols, chemistry, and dynamic vegetation. Including these components would transition AOGCMs to first generation earth system models. However, these components will introduce new feedbacks that will need to be understood through the analysis of sparse observations related to our limited understanding of how these components function in the climate system. These could include, for example, aerosol/cloud/climate feedbacks, vegetation/ocean/biogeochemistry/climate feedbacks. Assuming the IPCC AR5 publication date is early 2013, modeling groups are making decisions this year (2006) on what form their next generation models will take (to be used for climate change projections). The IPCC Task Group on New Emission Scenarios (TGNES) and other groups have been discussing new emission scenarios (e.g. mitigation/adaptation, also referred to as stabilization). These scenarios will come to bear on climate change projections performed for