Determinants of Uncertainty in Population Exposure to Climate-Related Extremes

Bryan Jones, National Center for Atmospheric Research (NCAR)
Brian C. O'Neill, National Center for Atmospheric Research (NCAR)

Climate change risks are a function of both the nature of physical hazards related to climate and the vulnerability of society and ecosystems to those hazards. Vulnerability can be viewed as a function of the exposure and sensitivity of society to hazards as well as its capacity to adapt. In this work we explore sources of uncertainty in the exposure component of vulnerability. Using extreme heat as an example, we consider alternative spatial population projections for the United States (2050) in conjunction with climate output from the North American Regional Climate Change Assessment Project to assess the variation in exposure to extreme heat resulting from alternative assumptions regarding population outcomes. Initial results indicate that broad scale assumptions regarding aggregate population totals and internal migration impact exposure moreso than smaller scale patterns of urban development. We conclude by reporting on our plan for completing this analysis over the coming months.