Background information

Starting at a workshop in 2006 (AGCI 2007), the scientific community began developing integrated global, regional, and sectoral scenarios to facilitate interdisciplinary research and assessment to explore the range of possible future climates and related physical changes; the challenges these changes could pose to human and natural systems; how these could interact with social, economic, and environmental development pathways; the degree to which mitigation and adaptation policies can avoid and reduce those risks; the costs and benefits of various policy mixes; residual risks under alternative pathways; and the relationship with sustainable development. Working together, climate change researchers from a broad range of perspectives and disciplines developed policy-relevant scenarios, exploring the implications of different possible futures for the challenges and opportunities human and natural systems could face with increasing climate change.

Key steps:

  • The integrated assessment modeling (IAM) community developed four emission pathways (Representative Concentration Pathways or RCPs) of how emissions could develop over the 21st century, considering the full basket of greenhouse gases, land use change, and other factors. Development of the RCPs is documented in a special issue of Climatic Change (van Vuuren et a, 2011). The RCPs were used as a basis for simulations with earth system models as part of the Climate Model Intercomparison Project (CMIP-5), producing projections of the magnitude and pattern of climate change over this century and, in some cases, to 2300 (Taylor et al., 2012).
  • The IAM and impacts, adaptation, and vulnerability (IAV) communities developed five global descriptions of future socioeconomic conditions that describe changes in demographics, human development, economy and lifestyle, policies and institutions, technology, and environment and natural resources over this century (Shared Socioeconomic Pathways or SSPs) (O’Neill et al. 2017). A special section of Global Environmental Change documents quantification of the SSPs (Riahi and van Vuuren, 2017).
  • Scenarios for use by the climate change science community are being created, integrating the descriptions of socioeconomic development with the climate change projections and with assumptions about climate policies (Kriegler et al. 2014).

Key meetings and workshops:

  • A roadmap to develop new scenarios was formalized at the 2007 Expert Meeting on Scenarios organized by the IPCC at Noordwijkerhout, Netherlands (Moss et al. 2008; Moss et al. 2010).
  • A team of authors from the IAM and IAV communities produced an overarching conceptual framework for developing and using SSPs (Core Writing Team, 2011).
  • A joint IPCC-NRC (U.S. National Research Council) workshop in Washington, DC, in February 2010 explored the needs for socioeconomic and environmental futures that could be used with climate scenarios (NRC, 2010) and could serve as a stimulus for proposed frameworks within which such scenarios could be developed (van Vuuren et al. 2012; Kriegler et al. 2012)
  • An IPCC Workshop on Socioeconomic Scenarios held in Berlin in November 2010 led to the adoption of a unified framework for the development of a small set of Shared Socioeconomic Pathways (SSPs) and their use in conjunction with the RCPs and associated climate model simulations to facilitate integrated research and assessment (IPCC, 2012).
  • In early November 2011, a meeting in Boulder, Colorado, adopted a basic set of narratives for the SSPs and laid out priorities for further activities (O’Neill et al., 2012).
  • A workshop co- sponsored by the IPCC and the government of the Netherlands in the Hague in May 2012 broadened the dialogue on the draft SSP narratives and presented initial quantifications of the SSPs. The meeting resulted in a draft plan of action for a range of joint IAV- IAM activities, pursued under the auspices of ICONICS.
  • IPCC Expert Meeting on Scenarios, in Laxenburg, Austria in May 2015 (IPCC, 2015).
  • First Forum on Scenarios for Climate and Societal Futures (“Scenarios Forum”) in Denver, Colorado, USA, March 2019 (O’Neill et al, 2019)
  • The second Forum on Scenarios for Climate and Societal Futures will take place in Laxenburg, Austria in June 2022. For more information see https://scenariosforum.org/