Essays on Climate Adaptation, Agriculture, and Health in Developing Countries

This thesis investigates the human consequences of two critical, yet understudied, aspects of climate change in the developing world: shifts in the timing of the rainy season and ocean acidification. It provides new empirical evidence on whether and how vulnerable populations adapt, the limits of their adaptation strategies, and the resulting impacts on various outcomes. Chapter 1 examines climate risk in Sub-Saharan Africa. Using microdata from six countries, I show that a one-week delay in the rainy season onset reduces yields by 2% and consumption by 1%. Damages disproportionately harm vulnerable female-managed plots, whereas education and wealth build resilience. Farmers adapt by delaying planting, but this is insufficient due to two informational frictions. Specifically, false onsets—rare but misleading early rains followed by a dry spell—trigger damaging premature planting. Negative impacts are concentrated in locations experiencing long-term climatic shifts, indicating a persistent failure to adapt. Projections suggest cumulative discounted losses from 2025 to 2050 could reach 10% of 2024 real GDP. These findings establish shifts in seasonal timing as a first-order economic threat and highlight the value of short-range forecasts. Chapters 2 and 3 shift focus to the world's oceans, establishing a causal link between ocean acidification and human health. Chapter 2 shows that increased ocean acidity adversely affects small-scale fisheries in 36 low- and middle-income countries. This shock propagates to households through a nutritional channel: reduced seafood availability leads to higher prices and diminished nutrient consumption by pregnant women, significantly increasing neonatal mortality risk. The analysis finds no evidence of contemporaneous adaptation. Building on these findings, Chapter 3 investigates long-run adaptation. I find no evidence that historically exposed communities have developed resilience; conversely, they appear more vulnerable. After quantifying the substantial historical mortality burden, I project future impacts: under a high-emissions scenario (RCP8.5) without adaptation, ocean acidification could cause 77.2 million cumulative neonatal deaths by 2100. However, a low-emissions pathway (RCP2.6) could avert nearly 40 million of these deaths. Collectively, these essays demonstrate that subtle environmental changes have economically important consequences, underscoring the need for policies that enhance adaptive capacity and address informational barriers.