The plot must thicken: a call for increased attention to social surprises in scenarios of climate futures

Climate change scenarios are typically based on trajectories of greenhouse gas emissions out into the future. These emissions are then incorporated into climate and earth system models to simulate pathways of global climate change. These pathways are often communicated as the average of numerous model simulations. Though essential for calculating the role of greenhouse gas emissions on the climate system, this approach inadvertently masks the fact that our future will conform to something akin to a single model simulation, or storyline-rather than the average of many simulations. Human responses to and interactions with these climate storylines will not necessarily be expected or rational. As such, potential social surprises could lead to multiple plotlines emerging from a single earth system storyline. Such social surprises are explored in three examples: net zero emissions achievement, low climate sensitivity, and solar climate intervention. Climate change scenarios are fundamentally dependent on policy pathways that in practice will be influenced by public perception and expectation. Thus, it is essential for climate change scenarios to recognize and incorporate the potential for heterogeneous social surprises to unexpected climate changes.