Quantitative estimates of the impacts of climate change on economic outcomes are important for public policy. We show that the vast majority of estimates fail to account for well-established uncertainty in future temperature and rainfall changes, leading to potentially misleading projections. We reexamine seven well-cited studies and show that accounting for climate uncertainty leads to a much larger range of projected climate impacts and a greater likelihood of worst-case outcomes, an important policy parameter. Incorporating climate uncertainty into future economic impact assessments will be critical for providing the best possible information on potential impacts.

Addressing climate change requires individual behavior change and voter support for pro-climate policies, yet surprisingly little is known about how to achieve these outcomes. In this paper, we estimate causal effects of additional education on pro-climate outcomes using new compulsory schooling law data across 20 European countries. We analyze effects on pro-climate beliefs and behaviors, as well as novel data on policy preferences and voting for green parties. Results show that a year of education substantially increases pro-climate beliefs, behaviors, and policy preferences.

Employing droughts and floods to proxy for changes in precipitation, this paper shows nomadic incursions into settled Han Chinese regions over a period of more than two thousand years—the most enduring clash of civilizations in history—to be positively correlated with less rainfall and negatively correlated with more rainfall. Consistent with findings that economic shocks are positively correlated with conflicts in modern sub-Saharan Africa when instrumented by rainfall, our reduced-form results extend this relationship to a very different temporal and geographical context, the Asian continent, and long historical period.

We examine the structure of preferences for mitigating impacts of global climate change that will not occur during the lifetimes of most who are alive today. Because no market data exist for such distant markets, a statedpreference approach is used. The analysis is based on the random-parameters logit model, and the results indicate substantial heterogeneity in respondent preferences, that mean willingness to pay is a significant and increasing function of the scope of the impact, and, provocatively, that respondents have the same preferences over the two very different time horizons that we consider.

We conduct a disaggregated empirical analysis of civil conflict at the subnational level in Africa over 1997 to 2011 using a new gridded data set. We construct an original measure of agriculture-relevant weather shocks exploiting within-year variation in weather and in crop growing season and spatial variation in crop cover. Temporal and spatial spillovers in conflict are addressed through spatial econometric techniques. Negative shocks occurring during the growing season of local crops affect conflict incidence persistently, and local conflict spills over to neighboring cells. We use our estimates to trace the dynamic response to shocks and predict how future warming may affect violence.

This research examines the climatic origins of the diffusion of Neolithic agriculture across countries and archaeological sites. The theory suggests that a foraging society's history of climatic shocks shaped the timing of its adoption of farming. Specifically, as long as climatic disturbances did not lead to a collapse of the underlying resource base, the rate at which hunter-gatherers were climatically propelled to experiment with their habitats determined the accumulation of tacit knowledge complementary to farming. Consistent with the proposed hypothesis, the empirical investigation demonstrates that, conditional on biogeographic endowments, climatic volatility has a hump-shaped effect on the timing of the adoption of agriculture.

Global phenomena, such as climate change, often have local impacts that are spatially correlated. We show that greater spatial correlation of productivities can increase international inequality by increasing the correlation between a country's productivity and its gains from trade. We confirm this prediction using a half-century of exogenous variation in the spatial correlation of agricultural productivities induced by a global climatic phenomenon. We introduce this general-equilibrium effect into projections of climate-change impacts that typically omit spatial linkages and therefore do not account for the global scope of climate change. We project greater international inequality, with higher welfare losses across Africa.

We document the individual willingness to act against climate change and study the role of social norms in a large sample of US adults. Individual beliefs about social norms positively predict pro-climate donations, comparable in strength to universal moral values and economic preferences. However, we document systematic misperceptions of social norms. Respondents vastly underestimate the prevalence of climate-friendly behaviors and norms. Correcting these misperceptions in an experiment causally raises individual willingness to act against climate change and individual support for climate policies. The effects are strongest for individuals who are skeptical about the existence and threat of global warming.

With climate change as prototype example, this paper analyzes the implications of structural uncertainty for the economics of low-probability, high-impact catastrophes. Even when updated by Bayesian learning, uncertain structural parameters induce a critical “tail fattening” of posterior-predictive distributions. Such fattened tails have strong implications for situations, like climate change, where a catastrophe is theoretically possible because prior knowledge cannot place sufficiently narrow bounds on overall damages. This paper shows that the economic consequences of fat-tailed structural uncertainty (along with unsureness about high-temperature damages) can readily outweigh the effects of discounting in climate-change policy analysis.

We investigate the impact of climate shocks on farmer-herder violence, using geolocalized data on conflict events for Africa, 1997-2014. We find that a one degree temperature increase yields a 54% increase in conflict probability in mixed areas populated by both farmers and herders (versus 17% in non-mixed areas). Quantifying the impact of projected climate change in 2040, we find that -when factoring in the magnifying effect of mixed settlements- annual conflicts are predicted to rise by a third. Drawing on a fine-grained analysis of groups' mobility patterns, we show that resource competition is a major driver of farmer-herder violence.