Which scenario should I use?
Use more than one, and choose them by your question and your time horizon. Our climate projections come in three scenarios: SSP1-2.6 (low emissions), SSP2-4.5 (intermediate) and SSP5-8.5 (very high). See Shared Socioeconomic Pathways for what each one assumes.
The time horizon matters most
Section titled “The time horizon matters most”Until about 2040 the scenarios hardly differ in global warming; they separate after mid-century.
Table 1. Global warming relative to 1850–1900 for our three scenarios, best estimates (IPCC, 2021, Table SPM.1).
| Period | SSP1-2.6 | SSP2-4.5 | SSP5-8.5 |
|---|---|---|---|
| 2021–2040 | 1.5 °C | 1.5 °C | 1.6 °C |
| 2041–2060 | 1.7 °C | 2.0 °C | 2.4 °C |
| 2081–2100 | 1.8 °C | 2.7 °C | 4.4 °C |
For decisions over the next 15 to 20 years, the differences between climate models and the natural ups and downs of the climate weigh more than the choice of scenario (Hawkins and Sutton, 2009). For long-lived assets, such as buildings, infrastructure or forests, the scenario drives the result.
By purpose
Section titled “By purpose”| Purpose | Scenarios |
|---|---|
| Physical risk screening or stress test | SSP5-8.5, the high end of the scenarios: the change you need to be able to withstand |
| Planning and adaptation design | SSP2-4.5 as the central case, with SSP5-8.5 as the stress test |
| Paris-aligned or transition analysis | SSP1-2.6, with a higher scenario alongside for physical risk |
What reporting frameworks ask
Section titled “What reporting frameworks ask”- CSRD. The European sustainability reporting standard on climate, ESRS E1 as adopted in 2023, asks companies to identify climate-related hazards “considering at least high emission climate scenarios”, for example IPCC SSP5-8.5 (European Commission, 2023, ESRS E1, paragraph 20 and AR 11).
- TCFD. Its recommendations ask companies to describe the resilience of their strategy “taking into consideration different climate-related scenarios, including a 2°C or lower scenario” (TCFD, 2017). Among ours, SSP1-2.6 is that scenario: 1.8 °C by 2081–2100 in the IPCC’s best estimate.
Other scenarios
Section titled “Other scenarios”Our standard datasets cover SSP1-2.6, SSP2-4.5 and SSP5-8.5. Other CMIP6 scenarios can be produced on request when the climate models have run them, for example SSP3-7.0 (high emissions without climate policy, 3.6 °C by 2081–2100) or SSP1-1.9 (the 1.5 °C pathway, 1.4 °C by 2081–2100) (IPCC, 2021, Table SPM.1). Ask us which scenarios, models and variables are available for your needs.
Use all five models
Section titled “Use all five models”Whatever the scenario, use the five climate models of our datasets rather than one: how far they agree shows how certain the change is (Noël et al., 2022).
Need projections for your sites? See our climate projections or request data.
References
Section titled “References”- European Commission (2023). Commission Delegated Regulation (EU) 2023/2772 supplementing Directive 2013/34/EU as regards sustainability reporting standards, Annex I, ESRS E1 Climate change. https://eur-lex.europa.eu/eli/reg_del/2023/2772/oj
- Noël, T., Loukos, H., Defrance, D., Vrac, M., & Levavasseur, G. (2022). Extending the global high-resolution downscaled projections dataset to include CMIP6 projections at increased resolution coherent with the ERA5-Land reanalysis. Data in Brief, 45, 108669. https://doi.org/10.1016/j.dib.2022.108669
- IPCC (2021). Summary for Policymakers. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (pp. 3–32). Cambridge University Press. https://doi.org/10.1017/9781009157896.001
- TCFD (2017). Final Report: Recommendations of the Task Force on Climate-related Financial Disclosures. https://www.fsb-tcfd.org/recommendations/
- Hawkins, E., & Sutton, R. (2009). The potential to narrow uncertainty in regional climate predictions. Bulletin of the American Meteorological Society, 90(8), 1095–1107. https://doi.org/10.1175/2009BAMS2607.1