What are Shared Socioeconomic Pathways, or SSPs?

Shared Socioeconomic Pathways (SSPs) are scenarios used in climate research to explore how global society, demographics, and economics might evolve over the 21st century, affecting greenhouse gas emissions and climate change. They describe five distinct pathways that represent different ways the world could develop in terms of population growth, economic development, technological progress, energy use, and environmental policies.

• SSP1 ("Sustainability") envisions a world making significant efforts toward sustainability, with low inequality, green energy, and sustainable economic practices.
• SSP2 ("Middle of the Road") describes a future that continues on current trajectories, with moderate economic growth, technological development, and environmental awareness.
• SSP3 ("Regional Rivalry") projects a fragmented world with high population growth, limited technological advancement, and countries prioritizing self-reliance and security over cooperation.
• SSP4 ("Inequality") portrays a world with high inequality, where well-off regions focus on technology and carbon reduction while poorer regions face significant challenges.
• SSP5 ("Fossil-Fueled Development") imagines a future driven by rapid economic growth and high energy demands, primarily reliant on fossil fuels, with little effort to mitigate climate change.

These pathways are combined with different climate policies and mitigation strategies to model a range of potential climate futures, helping policymakers and researchers understand the potential outcomes of various choices and their impacts on global warming and societal well-being.