Drought is among the most ruinous of natural disasters and is expected to become increasingly prevalent in a warming world. In the future, natural hydroclimatic variability will be superimposed on continued human-driven changes to regional climate, with both long-term warming and regional drying likely to exacerbate droughts of the future. Among the greatest challenges of decadal prediction and climate change projection are the quantification of prolonged drought risk in vulnerable regions and the integration of knowledge about this risk into the decision-making processes of the many resource managers and other stakeholders who deal with drought.
This project focuses on a scale of drought variability - decadal to multidecadal - that is not well constrained by observations, nor well represented in models. The activity relies on the integrated use of satellite, instrumental, and paleoclimatic observations, along with climate models and analysis, to understand both the natural and human influences on drought, potential model biases, and the roles of land cover change (vegetation and dust), ocean temperatures, and other factors behind drought. The goal is to develop improved estimates of drought risk, as well as the improved partnerships between scientists and stakeholders that are required to reduce the vulnerability of society to drought. Key vulnerable regions will be identified, where natural variability and anthropogenic change combine to amplify the risk of prolonged, severe drought with large consequences: southwestern North America (US and Mexico), Australia, the Amazon, and West Africa/Sahel.
The strategy takes advantage of several unique observational, model and stakeholder resources: (1) an unprecedented number of simulations of the past millennium from a state-of-the-art Earth System Model (CESM; in addition to the CMIP5 archive); (2) an expanding set of published and emerging paleoclimate datasets from multiple proxies that reveal long observational histories of decadal-multidecadal hydroclimate variability; (3) a longstanding network of stakeholders and collaborators in the southwestern US, Mexico, and beyond with whom we can develop best practices in applying drought risk estimates to real-world problems across a broad social context; and (4) a long history of working on drought variability and stakeholder-driven.
