Toward a better understanding of the impacts from climate change on a modern agricultural system in the Walker River Basin: A paleo perspective

As the Earth continues to warm from increasing emissions of CO2 and other greenhouse gasses, many different research groups continue using global climate models to better understand and predict the associated spatial and temporal changes in temperature and precipitation patterns on the landscape. Although the models are generally in agreement that, as the emissions continue the planet will continue to warm, there is still considerable disagreement and uncertainty among the models on the changes in precipitation patterns in many regions, particularly in the western U.S. where significant agricultural activities exist that are extremely sensitive to changes in precipitation. There is, however, a significant body of research that has focused on further understanding how the climate has changed in the past through paleolake studies in the arid and semiarid regions of the western U.S. and other similar locations throughout the world. In particular, several studies have estimated reductions in annual precipitation by as much as 60% of modern values during the Medieval Climatic Anomaly (MCA). In this study, we utilize a detailed, high spatial resolution hydrologic model of the Walker River Basin to conduct a number of climate change studies aimed at assessing the impacts of a wide range of changes in climate variables (i.e. precipitation and temperature) on important agricultural variables (e.g., surface water irrigation, ground water pumping, crop yield, etc.) from the watershed to the farm scale. Specifically, we explore the impacts and resiliency of the modern Walker River watershed and agricultural systems under the climatic conditions that existed during the MCA and those that are forecasted to occur in the future based on popular emission studies using global climate models.