Sectoral Interactions, Compounding Influences and Stressors, and Complex Systems: Understanding Tipping Points and Non-Linear Dynamics

Socioeconomic and environmental forces (both gradual changes and extreme events) variably affect natural resources and physical systems—land, water, energy, air, transportation —across the United States. To manage these systems under changing conditions, decision-makers in communities, regions, and states require the ability to identify particularly vulnerable infrastructure and populations. They also need robust strategies aligned with economic development plans. By focusing research on risks of extremes and compounding events through integrated modeling of physical and socioeconomic systems, we gain insights on the vulnerabilities and resilience in a region, potential tipping points, and responses and feedbacks throughout these systems (Figure 1). 

A REGIONAL FOCUS 

The Mississippi River Basin serves as the region of focus to explore multi-sector dynamics with the goals of advancing understanding of interactions across systems and scales, developing frontier methods/tools, and assessing generalizability and extensibility.  A particular focus is on compounding human and natural system stressors and how they could exceed the resilience of coupled systems. Within the Mississippi River Basin, the focus is on connections within and between two sub-regions: (1) the lower Midwest, and (2) the central Gulf Coast. Both target sub-regions are susceptible to various common types of individual and/or compound extreme climate and weather events, including flooding, heat waves and drought, and are likely to experience changes in population, economic activity, infrastructure and transformation of energy, water, and land-using sectors. In exploring the convergence of human and natural systems and stressors in these regions, we seek to develop methods and acquire insights that have the potential to be transferred and extended to other regions, and more generally investigate the scope, specificity, model forms, details, interoperability, and data requirements for meaningful understanding of system dynamics over multiple scales.

CHALLENGES 

This project is designed to investigate the following overarching questions: 

• How can different tools / methods / scales be combined to provide new, transferable insights into MultiSector Dynamics (MSD)?
• What combinations of tools and capabilities are best aligned with different types of questions and “use case” features?
• How can MSD methods improve understanding of risks and stressors and their implications for physical and socio-economic systems?
• Are there differential responses of complex, interconnected physical and socioeconomic systems to slowly evolving stressors vs. extreme events?

APPROACH 

To address these questions, researchers (1) advance a multi-system modeling framework, (2) investigate regional use cases focused on (a) human-natural system interactions (socioeconomic-climate-energy-water-land-air-human health/well-being) and (b) transportation infrastructure and risk propagation in the context of multi-scale networks, and (3) test strategic pairings among systems to investigate the coevolution of the interconnected systems under multiple stressors. This involves enhancing and applying multiple tools, including:

• Coupled multi-system models to assess compounding stressors (Figure 2);
• Novel tools for: multi-system risk triage, uncertainty quantification, scenario discovery, spatial downscaling, and extreme event projection; 
• High resolution water quantity and quality modeling, and land use modeling;
• Multisector and multi-region energy-economic modeling;
• Conventional Earth system modeling as well as their emulation;
• Decision-making under uncertainty and stochastic dynamic program approaches; 
• Large ensembles of integrated human-Earth system scenarios; and
• Transportation infrastructure and network modeling. 

OUTCOMES 

This project will serve to advance the frontier of MSD methods, tools and understanding, providing insights into: 

• The coevolution of interconnected systems to multiple stressors, both individually and in different combinations, including how stressors interact and can either amplify or ameliorate risks. 
• How compounding influences and stressors affect patterns of economic and infrastructure development, stability of systems, complex interactions and feedbacks among systems, and regional teleconnections.
• How to bring different tools/capabilities together to analyze multiple system dynamics across multiple scales simultaneously.
• Uncertainty and risk propagation, compounding impacts, and potential tipping points.
• Particularly vulnerable areas, populations, system components and infrastructure.
• Potential adaptive responses to improve system resilience.
• Generalizability and extensibility of both MSD tools and insights.

Figure 1.  A complex “system of systems” comprises the MIT Center for Sustainability Science and Strategy’s research vision for future modeling studies and defines the scope of this project.

Figure 2. Schematic of the proposed modeling to integrate water, land, air, and human interactions.

DOE Award Number: DE-FG02-94ER61937

Project proposal PDF - June 2019

Project summary PDF - December 2022