Shared Socioeconomic Pathway

To address the RCPs’ limitations, a new set of scenarios called SSPs was developed (Kriegler et al., 2014; O’Neill et al., 2014; Van Vuuren et al., 2014). The SSPs are narratives that combine a range of socio-economic and technological factors with different GHG emissions pathways, thus specifying and standardising socio-economic foundations consistent with the RCPs (Moss et al., 2010; Van Vuuren et al., 2017). While the SSPs are based on future socioeconomic developments, such as population growth, economic growth, technological change, and social values, and how these factors will drive GHG emissions over time (O’Neill et al., 2014; Riahi et al., 2017), these assumptions are mainly qualitative descriptions. Hence, the SSPs need to be quantified to be usable for assessments and recommendations. This is the role of the Integrated Assessment Models (IAMs), a class of models used to study the complex interactions between human activity and the natural environment. Developed primarily by economists, climatologists, and energy system experts, IAMs simulate the SSPs with some level of granularity (on country and partially on sector level) and generate key variables such as GHG emissions, energy supply and demand (from various energy sources), mitigation costs, and other macroeconomic variables (NGFS, 2023a). Thus, IAMs combine multi-disciplinary information to support policymakers in understanding the impacts of their decisions on the environment, economy, and society.

_{Kriegler, E., Edmonds, J., Hallegatte, S., Ebi, K.L., Kram, T., Riahi, K., … van Vuuren, D.P. (2014). A new scenario framework for climate change research: The concept of shared climate policy assumptions.}_{Climatic Change, 122}_{, 401-414.}_{https://doi.org/10.1007/s10584-013-0971-5}

_{Moss, R.H., Edmonds, J.A., Hibbard, K.A., Manning, M.R., Rose, S.K., van Vuuren, D.P., … Wilbanks, T.J. (2010). The next generation of scenarios for climate change research and assessment.}_{Nature 463}_{, 747-756.}_{https://doi.org/10.1038/nature08823}

_{NGFS (2023a). NGFS climate scenarios. Technical Documentation. V4.1.}_{Network for Greening the Financial System}_._{https://www.ngfs.net/sites/default/files/media/2023/11/07/ngfs_scenarios_technical_documentation_phase_iv.pdf}

_{O’Neill, B.C., Kriegler, E., Riahi, K., Ebi, K.L., Hallegatte, S., Carter, T.R., … van Vuuren, D.P. (2014). A new scenario framework for climate change research: The concept of shared socioeconomic pathways.}_{Climatic Change, 122}_{, 387-400.}_{https://doi.org/10.1007/s10584-013-0905-2}

_{Riahi, K., van Vuuren, D.P., Kriegler, E., Edmonds, J., O’Neill, B.C., Fujimori, S., … Tavoni, M. (2017). The Shared Socioeconomic Pathways and their energy, land use, and greenhouse gas emissions implications: An overview.}_{Global Environmental Change, 42}_{, 153-168.}_{https://doi.org/10.1016/j.gloenvcha.2016.05.009}

_{Van Vuuren, D.P., Kriegler, E., O’Neill, B.C., Ebi, K.L., Riahi, K., Carter, T.R., … Winkler, H. (2014). A new scenario framework for climate change research: scenario matrix architecture.}_{Climatic Change, 122}_{, 373-386.}_{https://doi.org/10.1007/s10584-013-0906-1}

_{Van Vuuren, D.P., Riahi, K., Calvin, K., Dellink, R., Emmerling, J., Fujimori, S., … O’Neill, B. (2017). The shared socio-economic pathways: Trajectories for human development and global environmental change.}_{Global Environmental Change, 42}_{, 148-152.}_{https://doi.org/10.1016/j.gloenvcha.2016.10.009}