Anthropogenic emissions of greenhouse gases (GHG) over the past two centuries have resulted in rapid climate change. Current projections of climate change, driven by representative concentration pathways (RCPs) reflect static projections of human greenhouse gas (GHG) emission behaviors. In reality, GHG emissions will be driven by dynamic interactions between the climate and human systems as climate change alters the frequency of extreme climate events, influencing human perception of risk from climate change, and emissions behaviors. Emissions behaviors, in turn, influence the magnitude of climate change.
The global distribution of GHG emissions are largely spatially discordant with climate change impacts. Feedbacks between the human and climate systems are likely to be sensitive to this discordance: The emissions behavior of populations in regions that are experiencing lesser impacts of global climate change may diverge from populations experiencing larger climate change impacts. We develop a simple spatially-implicit dynamical model that couples a climate and emissions behavior models to examine the effect of spatial discordance of patterns of GHG emissions and climate impacts.
Results/Conclusions
We show that the magnitude and trajectory of future climate change is sensitive to feedbacks between the human and climate systems. The uncertainty in climate change that comes from uncertainty in human behavioral responses is of a similar magnitude to the uncertainty that stems from the climate system. Spatial discordance between where GHG emissions occur and impacts are felt can lead to dramatically different Earth system dynamics. We show that sequestration strategies as opposed to purely mitigation strategies can be used to offset spatial discordance in emissions/impacts as also can strong perceived social norms that operate across regions. Finally, the inclusion of feedbacks between humans and climate provides for improved representation of the complexity of the Earth system.