The Spatial and Dynamic Patterns of Climate Variability and Change in the United States

Abstract

Many adaptation and mitigation measures related to climate change require a temporally relevant understanding and for action to be taken at all levels of political jurisdiction. We analyze the developments of county experiences from the years 1895 to 2023 within the CONUS, Western U.S., Arizona, and Minnesota by employing numerous methods. The first descriptive statistical methods examine overall trends and discern how average, maximum, and minimum temperatures and precipitation patterns have changed in variability, spatial variation, as well as how the distributions have developed over time. Polarization indices are then used to analyze how the climatic experiences of counties have grown, be it more similar or less similar. We find that, for most counties, temperature variables have decreased in variability and precipitation has negligibly changed, implying a convergence of temperature ranges and minute shifts in the variability of precipitation. For most counties, the polarization of temperature variables has also decreased, while the polarization of precipitation has changed very little, suggesting that county experiences of temperature across the United States have generally become more alike and that precipitation experiences have changed little. Meanwhile, elements of spatial variation are exhibited through varying levels of significance across our selected regions, and the primarily opposing directions of results in Arizonan summers, which frequently exhibit increases in both variability and polarization.