Abstract: This Perspective evaluates recent progress in modeling nature–society systems to inform sustainable development. We argue that recent work has begun to address longstanding and often-cited challenges in bringing modeling to bear on problems of sustainable development. For each of four stages of modeling practice—defining purpose, selecting components, analyzing interactions, and assessing interventions—we highlight examples of dynamical modeling methods and advances in their application that have improved understanding and begun to inform action. Because many of these methods and associated advances have focused on particular sectors and places, their potential to inform key open questions in the field of sustainability science is often underappreciated. We discuss how application of such methods helps researchers interested in harnessing insights into specific sectors and locations to address human well-being, focus on sustainability-relevant timescales, and attend to power differentials among actors. In parallel, application of these modeling methods is helping to advance theory of nature–society systems by enhancing the uptake and utility of frameworks, clarifying key concepts through more rigorous definitions, and informing development of archetypes that can assist hypothesis development and testing. We conclude by suggesting ways to further leverage emerging modeling methods in the context of sustainability science.

Authors' Summary: Solar geoengineering is a proposed set of technologies to help lessen the impacts of climate change by reducing the amount of sunlight received by the Earth. Stratospheric aerosol injection is a method of solar geoengineering that reduces sunlight by increasing the amount of aerosol particles in the stratosphere, a process which can also cause stratospheric ozone depletion. Nearly all studies of stratospheric aerosol injection have focused exclusively on the direct impacts of increased stratospheric aerosol on climate. However, changes in sunlight also alter the rates of chemical reactions throughout the atmosphere, changing the concentrations of greenhouse gases that affect climate like methane and tropospheric ozone.

Our results show that these changes in greenhouse gases due to geoengineering chemical feedbacks can substantially alter the climate effect of geoengineering, especially on regional and seasonal scales. Our results also show that geoengineering-induced stratospheric ozone depletion can lead to net global health benefits, as the impacts on mortality from overall improvements in surface air quality due to chemical feedbacks outweigh those from increases in UV exposure. These same chemical feedbacks can also improve crop yields and overall plant growth.

Our results underscore the risk of surprises that could arise from solar geoengineering.