The IPCC AR5 Scenarios Database documents the long-term scenarios as reviewed in the Fifth Assessment Report (AR5) of Working Group III of the Intergovernmental Panel on Climate Change (IPCC).

The IPCC AR5 scenarios database comprises 31 models (sometimes in different versions) and in total 1,184 scenarios. In an attempt to be as inclusive as possible, an open call for scenarios was made through the Integrated Assessment Modeling Consortium (IAMC) with approval from the IPCC WGIII Technical Support Unit.

To be included in the database, four criteria had to be met. First, only scenarios published in the peer-reviewed literature could be considered, per IPCC protocol. Second, the scenario must contain a minimum set of required variables and some basic model and scenario documentation (meta data) must be provided. Third, only models with at least full energy system representation were considered given that specific sectoral studies were assessed in Chapters 8-11 of the report. Lastly, the scenario must provide data out to at least 2030.

Scenarios were submitted by entering the data into a standardized data template that was subsequently uploaded to this database system administered by IIASA. The AR5 scenario database is documented in Annex II, Section A.II.10, of the 5th Assessment Report of Working Group III. For the purpose of the assessment, scenarios have been grouped in various categories relating to, among other things, radiative forcing outcome in 2100, overshoot, technology availability and policy assumptions (see Annex A.II.10.3 for a detailed description). The classification of individual scenarios can be downloaded here.

Model comparison projects

A majority of scenarios was provided by model comparison projects which have published their scenario data in project specific databases. These project scenario databases can hold more information than is provided here. Scenario data from this site may be freely used for non-commercial and educational purposes with proper acknowledgment of the data sources. The data source is specified in the scenario name (i.e. the project name in most cases). Users are requested to ensure proper acknowledgment of the data sources of the scenarios they use as detailed below. Table A.II.15 from Annex II provides information about the model comparison projects that are represented in the AR5 scenario database. In particular, it lists the number of models and scenarios included in the database, the areas in which models were harmonized, the leading institutions and references to the overview publications.