Climate Change

Climate change increasingly disrupts the infrastructure underpinning global trade. Maritime chokepoints are particularly exposed: localized shocks can propagate through shipping networks, generating welfare losses far beyond the directly affected region. This paper studies this mechanism using the Panama Canal, whose lock system relies on a freshwater reservoir (Gatun Lake), making transit capacity directly sensitive to hydrological conditions. I develop a structural maritime network model with endogenous routing and network spillovers to quantify how water scarcity propagates through global shipping routes and affects U.S. international trade. At the network level, a one-foot decline in lake levels raises transport costs on Canal links by approximately 0.19%, triggering rerouting and increased traffic along alternative corridors. The resulting welfare effects are highly uneven across U.S. states, with losses concentrated along the East and Gulf Coasts and modest gains on the Pacific Coast. While reduced-form estimates imply that a one-foot decline in lake levels lowers trade on Canal-dependent routes by about 2–3%, general-equilibrium network effects amplify this impact. Accounting for rerouting and network spillovers, trade declines by approximately 8% on average across affected routes.

We decompose state-level U.S. agricultural greenhouse gas emissions growth into output growth, input emission intensity, and total factor productivity (TFP). Combining EPA emissions data with USDA productivity accounts over 1990–2015, we find that TFP growth historically slowed emissions but has recently weakened. Declining input emission intensity, concentrated in the Southeast, has become the dominant mitigating factor. Further decomposition suggests that land productivity gains are more closely linked to emission reductions than labor productivity gains.

Studies analyzing the impact of climate change on agriculture mostly emphasize effects on production quantity, overlooking potential impacts on quality and nutritional content. We explore this question in the context of U.S. milk production which represents about 20% of national animal products. We link individual lactation records for over 6.5 million cows over 2007-2016 with high-resolution weather data to estimate the nonlinear effects of heat on both milk yield and quality (composition in fat and protein). While milk yield declines sharply only when the Temperature-Humidity Index (THI) exceeds 70 (primarily in the summer), milk quality decreases steadily with rising THI (throughout the year). Combining these findings indicates that estimates of heat damages that ignore quality effects –common in the literature– underestimate total economic losses by at least a factor of two. We also find that the sensitivity of both milk yield and quality to heat varies little with cow age, farm size, region of the country, or period in the sample, suggesting there has been little progress in adapting U.S. dairy systems to a warming climate.

Global population growth has increased food demand, particularly in emerging economies such as Latin America. There, the subsequent increase in livestock production has been a main driver of greenhouse gas emissions and deforestation. Silvopasture emerges as a promising solution for both economic and environmental sustainability. However, to be successful, cattle ranchers need to implement (set-up) and afterwards adopt (continued use after implementation) silvopasture. Although resources have been invested in the implementation of silvopastoral systems in Colombia, adoption rates remain variable. In this study, we aim to understand the barriers to adoption of silvopasture in Colombia by surveying 182 ranchers who received technical assistance and payment for ecosystem services to implement silvopasture in Colombia. We used survey results and precipitation and temperature data to identify socioeconomic and environmental variables that could explain the varying levels of adoption among ranchers. Our results indicate that high precipitation and temperature during the dry season have a negative impact on adoption. Ranchers who have experienced food insecurity are more likely to adopt while ranchers with larger farms, tractors, and water pumps, all indicators of good economic status, are less likely to adopt silvopastoral applications. Collectively, our data suggests that ranchers facing economic and environmental challenges are more likely to adopt silvopastoral technologies. This highlights the need for future implementation programs to focus on socially and environmentally vulnerable farmers, who stand to benefit the most and are more likely to maintain these practices long-term.