Shared Socioeconomic Pathways

Atmospheric CO₂ concentrations by SSP across the 21st century

Methane emissions projections

Shared Socioeconomic Pathways

Shared Socioeconomic Pathways (SSPs) are a set of scenarios developed to explore the challenges to mitigation of and adaptation to climate change. They are part of a framework that integrates climate change science more closely with the broader issues of sustainable development, including the goals related to poverty, economy, and environment in the 21st century. The SSPs are designed to provide a basis for making future projections of greenhouse gas emissions and to assess the implications of these emissions for climate change.

Overview

The concept of Shared Socioeconomic Pathways was developed to improve upon the earlier Special Report on Emissions Scenarios (SRES) by providing a more detailed exploration of the possible futures in terms of socioeconomic challenges for climate change mitigation and adaptation. The SSPs are part of a new framework that also includes Representative Concentration Pathways (RCPs), which are used to project changes in atmospheric concentrations of greenhouse gases, and climate change impacts, adaptation, and vulnerability (IAV) research.

The SSP framework consists of five pathways (SSP1-SSP5), each based on different assumptions about demographics, economic development, energy, land use, and technology. These pathways describe different futures in terms of the severity of climate change and the ability of societies to mitigate and adapt to its impacts.

The Five Shared Socioeconomic Pathways

• SSP1: Sustainability – Taking the Green Road (Low challenges to mitigation and adaptation)
• SSP2: Middle of the Road (Medium challenges to mitigation and adaptation)
• SSP3: Regional Rivalry – A Rocky Road (High challenges to mitigation and adaptation)
• SSP4: Inequality – A Road Divided (Low challenges to mitigation, high challenges to adaptation)
• SSP5: Fossil-fueled Development – Taking the Highway (High challenges to mitigation, low challenges to adaptation)

Each SSP outlines a unique narrative describing how global society, economies, and environments might evolve over the 21st century, leading to different challenges and opportunities for mitigating and adapting to climate change.

Applications

The SSPs are used in climate modeling and climate change impact assessments, including the Intergovernmental Panel on Climate Change (IPCC) reports. They provide a consistent set of parameters for analyzing how different aspects of society and the economy might influence greenhouse gas emissions and climate change outcomes. This allows researchers and policymakers to explore the effectiveness of different mitigation and adaptation strategies under various future scenarios.

Challenges and Criticisms

While the SSPs represent a significant advancement in the integration of socioeconomic factors with climate change research, they are not without their challenges and criticisms. One issue is the complexity and uncertainty involved in projecting future socioeconomic conditions. Additionally, the SSPs have been critiqued for their reliance on quantitative models, which may not fully capture the complexities of human-environment interactions.

Conclusion

The Shared Socioeconomic Pathways provide a valuable tool for understanding the potential socioeconomic challenges to addressing climate change. By exploring a range of possible futures, the SSPs help to highlight the importance of sustainable development in mitigating and adapting to climate change. As research continues to evolve, it will be crucial to refine these pathways and address the criticisms to better support global efforts towards a sustainable and resilient future.