ORIGINAL PAPER Climate and human health: synthesizing environmental complexity and uncertainty James D. Tamerius Æ Erika K. Wise Æ Christoper K. Uejio Æ Amy L. McCoy Æ Andrew C. Comrie Published online: 17 April 2007 Ó Springer-Verlag 2007 Abstract Broad relationships between weather and human health have long been recognized, and there is currently a large body of research examining the impacts of climate change on human health. Much of the literature in this area examines climate–health relationships at global or regional levels, incorporating mostly generalized responses of pathogens and vectors to broad changes in climate. Far less research has been done to understand the direct and indirect climate-mediated processes involved at finer scales. Thus, some studies simplify the role of climate and may over- or under-estimate the potential response, while others have begun to highlight the subtle and complex role for climate that is contingent on other relevant processes occurring in natural and social environments. These fun- damental processes need to be understood to determine the effects of past, current and future climate variation and change on human health. We summarize the principal climate variables and climate-dependent processes that are believed to impact human health across a representative set of diseases, along with key uncertainties in these rela- tionships. Keywords Climate Á Disease Á Ecology Á Environment Á Health 1 Introduction Empirically-based ecological and public health studies demonstrate that climatic variables are engaged in numer- ous processes that affect human health risks. However, these climate-mediated processes are of variable impor- tance in understanding and predicting human health. Health risks are modulated by physical, geographical, biological, genetic, social, cultural, and political environments and are continuously shaping and being shaped by each other. The complex interaction between hosts, reservoirs, vectors and agents of disease results in the dispersion, emergence, reproduction, and persistence of health risks. Much of the prior literature examines climate–health links at global and national scales. Relatively less attention has been paid to outlining direct and indirect climate–health processes at finer scales. Depending on their scale, some studies may therefore over- or under-estimate the potential climate–health response, while a more limited number highlight the complex and contingent role of climate in tandem with other natural and social processes. Previous reviews have examined the social inequities of climate and health impacts, regional assessments of environmentally sensitive health outcomes, and synergistic climate and health impacts on the economy (e.g. Patz et al. 2005; Kolivras and Comrie 2004; Epstein and Mills 2005). Mul- tiple disciplinary perspectives of health, society, and the environment are required to understand human and disease ecology and manage health risk. Adoption of Geographic Information Science perspectives and methods is wide- spread and growing in public health, veterinary medicine, and environmental modeling (e.g., Elliott 2000; Cromley and McLafferty 2002). Other geographical ways of know- ing such as political ecology, critical geography, and physical geography challenge and re-conceptualize social, J. D. Tamerius Á E. K. Wise Á C. K. Uejio Á A. C. Comrie (&) Department of Geography and Regional Development, University of Arizona, Harvill Building, Box #2, Tucson, AZ 85721, USA e-mail: comrie@arizona.edu A. L. McCoy Arid Lands Resource Sciences, University of Arizona, 1955 East Sixth Street, PO Box 210184, Tucson, AZ 85719, USA 123 Stoch Environ Res Risk Assess (2007) 21:601–613 DOI 10.1007/s00477-007-0142-1