New Scenarios

Case Study from IIASA Annual Report 2011: 

IIASA  is developing new scenarios to underpin work of the upcoming Fifth Assessment Report of the  Intergovernmental Panel on Climate Change (IPCC AR5) 

Representative Concentration Pathways (RCPs)

As part of research for the upcoming Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5), which aims to provide a clear and up to date view of the current state of scientific knowledge relevant to climate change, the Energy Program (ENE) and the Transitions to New Technologies Program (TNT) in 2011 finalized work on one of the four new Representative
Concentration Pathways (RCPs), that will underpin the AR5: RCP 8.5 scenario of relatively high greenhouse gas emissions, developed by ENE's Keywan Riahi’s MESSAGE modeling team. A special Issue of Climate Change, co-edited by Keywan Riahi was published in 2010 to document the main assumptions and characteristics of the RCPs and the steps involved in their development. 

Shared Socioeconomic Pathways (SSPs)

IIASA began work in 2011 on quantifying one of the five new Shared Socioeconomic Pathways (SSPs) which will be used alongside the RCPs to analyze feedbacks between climate change and socioeconomic factors, like world population growth, economic development, and technological progress. In the process, related issues like environmental status, effectiveness of national institutional efforts against climate change, and progress in poverty alleviation will come under the microscope.

To develop the new SSPs, ENE spearheaded a cross-program collaboration with IIASA’s
World Population (POP) and Ecosystem Services Management (ESM) programs. Integrated  SSP scenarios were developed covering energy, land-use, and the social dimension of future transformations. ENE is also supporting the overall process by hosting the SSP database, which will become the major dissemination tool for SSP data.

RCPs, SSPs and how they integrate into IPCC AR5

The new two-pronged RCP/SSP framework provides the foundation for an integrated approach and improved assessment of climate change vulnerabilities, adaptation, and mitigation needs. The RCPs facilitate the work of the climate modeling community (CM), while the SSPs will serve the integrated assessment modeling community (IAM) and the vulnerability, impacts, and adaptation (VIA) community. The overarching aim is to integrate, in a consistent and timely manner, the work of these three communities, whose research corresponds to the three main working groups of the IPCC.

Strengthening cooperation between these groups, and most importantly, facilitating and expediting the development of more consistent and comparable research within and across them, will take climate research through to the IPCC's Fifth Assessment Report and beyond.

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Last edited: 17 October 2014


Since 1994, IIASA's researchers have contributed to the Intergovernmental Panel on Climate Change.

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