As climate hazards and their associated socioeconomic impacts become more severe, individuals and governments across the globe are reckoning with how best to adapt. For some, this might entail staying in place and altering their behaviors, livelihoods and investments as temperatures rise and rainfall becomes more variable. For others, however, the increased risk of physical harm, economic loss and social instability wrought by worsening climatic conditions may compel them to migrate in search of security elsewhere. Identifying how climate phenomena influence human movement can be straightforward, such as forced displacement that occurs following the physical destruction of a storm, flood or fire; however, in many instances, the climate-migration relationship is more opaque. Impacts on economic productivity, health and wellbeing from chronic stressors like drought, heatwaves, desertification and sea level rise may spur certain members of an afflicted region to out-migrate, while limiting the ability of others to do so, and will occur amidst a multitude of other, non-climatic influencing factors. Therefore, disentangling the manner and extent to which climate has driven human migration in the past, and the potential for it to do so in the future, is a challenging yet critical priority to shaping robust, proactive adaptation policies and humane migration governance frameworks moving forward.

This dissertation helps address this need by investigating the intersection of climate impacts, inequities and human displacement in various contexts. It is segmented into three distinct chapters based on relevance to i) Central America, ii) the United States and iii) global coastlines, regions in which climate-migration dynamics are likely to become increasingly relevant. The chapters are comprised of the following project-based subsections: (i) assessing 21st century drought projections in Central America’s Dry Corridor, which finds that seasonal and annual-scale droughts in the region are projected to lengthen, intensify and increase in frequency throughout the remainder of the century; (ii) modeling of international emigration and internal migration, as reported in the Guatemalan 2018 national census, using sociodemographic, physical and climatic covariates, finding various sociodemographic variables and drought stress as significant predictors of out-migration from the country; (iii) reviewing literature linking climate hazards, internal displacement, movement and inequities in the United States, which assesses the complex manner by which acute and chronic climatic hazards impact human displacement and exacerbate social inequality; (iv) producing high-resolution dasymetric maps of population in California using the 2020 census for various demographic subgroups, which are publicly available and useful in evaluating geospatial population distributions across the state for any number of research applications, and which to date have included numerous climate change, environmental justice and health equity studies; (v) conducting geospatial analysis of Hurricane Maria’s impact on Puerto Rican power supply, recovery and re-electrification and correlational relationships to subsequent out-migration, with constructed models explaining up to 82% of observed variance in post-storm power outage patters, indicating both physical and socioeconomic variables as being significant predictors of prolonged recovery; and (vi) creating an open-source coastal impacts and adaptation modeling platform along fine-scale global coastlines for multiple scenarios of 21st century sea level rise, which was used to inform the U.S. Environmental Protection Agency’s updated social cost of carbon estimate and suggests that, globally, between 16-46 million people are expected to relocate inland by 2100 if optimal adaptation strategies are undertaken and up to 200 million people under high-end sea level rise and sub-optimal adaptation pathways.

Climate change is set to have a significant economic impact, affecting our behavior and changing the ways we produce and consume. This dissertation illustrates different channels through which environmental change has already been impacting our economy and highlights potential measures and market designs to mitigate future costs. The first two chapters of this dissertation leverage historical weather data to assess the market and behavioral responses to extreme temperature shocks. Chapter 1 utilizes European electricity markets data to assess the non-linear relationship between weather and energy cost. The analysis of spot market electricity prices reveals that estimates of the energy cost due to climate change which rely solely on consumption are significantly biased downward. In addition, the creation of a ``unified'' European market through regional market integration has contributed to drastically lower the impact of extreme temperatures on electricity price. Chapter 2 demonstrates that warm temperatures are associated with a rise in violent crime in the US. I further investigated the effect of extreme weather on police officer behavior using original and novel crowd-sourced data on civilian deaths involving police. The results indicate that fatal shootings increase proportionately to the growing number of violent crimes during warmer days. Taser use and physical restraints --- two controversial uses of force --- increase significantly on such days regardless of the threat level, indicating a need to reevaluate their usage. Finally, chapter 3 explores the distribution of human attention to moments in time using Google search data. Attention is a key parameter in the field of environmental economics as public policies enacted today are a direct function of how much people value the past, current, and future states of the economy. The results suggest strong common patterns of thought with respect to time, however recent trends and regional variations indicate that some non-biological factors can alter these patterns slightly.

In this dissertation, the reader will find four essays examining the empirical effects of future climate change, while accounting for both adaptation as well as its costs. In three of these essays, we uncover climate impacts that result in a substantially altered future from

our present reality: crop yields in sharp decline (while accounting for costly adaptation); cropped areas shifted away from present-day locations; and increased human mortality, with costly adaptations undertaken to avoid even further excess deaths. In one essay, we estimate that the impact of climate change on global energy consumption will be small in aggregate due to offsetting effects from more hot days but fewer cold days, though regional disparities may be important.

Several conclusions follow. First, accounting for both adaptation and its costs is important for grounding an accurate estimate of the social cost of carbon. Second, performing these analyses at a global scale and with high spatial resolution reveals important sources of heterogeneity -- both in impacts as well as in the magnitude of adaptation. Third, results such as these may be useful inputs to the Integrated Assessment Modeling community, improving the empirical grounding of the damage functions employed.

In these essays, we seek to include information from as globally representative a sample as possible, and where possible estimate heterogeneous effects for the global rich versus the global poor. We also seek to graphically illustrate projected effects so that non-expert readers can locate themselves within the empirical estimates we produce.

Many questions of importance for sustained human progress on a planet of finite resources remain unanswered. As environmental change accelerates, there is growing urgency to build an understanding of how the environment and society influence one another. This dissertation mobilizes novel, large-scale datasets in combination with methodological advances in casual inference and original theoretical contributions to study the interdependence between societies, economies, and two of the world's most vital natural endowments: the climate and freshwater. Throughout these essays, I estimate causal, policy-relevant relationships between global-scale processes of environmental change and human wellbeing. The first three essays provide new estimates of the climate's influence over market and non-market outcomes, generating insights in climate impact attribution, climate impact mechanisms, and the estimation of adaptation costs and benefits under anthropogenic climate change. The final essay studies the other direction of the society-environment relationship, measuring how changes in economic systems influence freshwater. This chapter uses satellite data to uncover links between agricultural policies and water depletion at a scale that has been impossible to investigate with standard water monitoring tools. Together, these essays aim to demonstrate that combination of data and methods across physical and social sciences can yield valuable answers to questions that have been discussed, debated, and left unresolved for generations.