Shared Socioeconomic Pathways

Predicted atmospheric CO₂ concentrations for different shared socioeconomic pathways (SSPs) across the 21st century (projected by MAGICC7, a simple/reduced complexity climate model). Each data point represents an average of simulated values generated from five integrated assessment models.

Shared Socioeconomic Pathways (SSPs) are climate change scenarios of projected socioeconomic global changes up to 2100 as defined in the IPCC Sixth Assessment Report on climate change in 2021. They are used to derive greenhouse gas emissions scenarios with different climate policies. The SSPs provide narratives describing alternative socio-economic developments. These storylines are a qualitative description of logic relating elements of the narratives to each other. In terms of quantitative elements, they provide data accompanying the scenarios on national population, urbanization and GDP (per capita). The SSPs can be quantified with various Integrated Assessment Models (IAMs) to explore possible future pathways both with regard to socioeconomic and climate pathways.

The five scenarios are:

  • SSP1: Sustainability ("Taking the Green Road")
  • SSP2: "Middle of the Road"
  • SSP3: Regional Rivalry ("A Rocky Road")
  • SSP4: Inequality ("A Road Divided")
  • SSP5: Fossil-fueled Development ("Taking the Highway")

There are also ongoing efforts to downscaling European shared socioeconomic pathways (SSPs) for agricultural and food systems, combined with representative concentration pathways (RCP) to regionally specific, alternative socioeconomic and climate scenarios.