Silver Bullets: Cloud Seeding and Water Resources in California

Abstract: Management of water resources presents complex challenges, especially in drought-prone regions where water scarcity affects energy production, agriculture, and urban water supplies. Weather modification, such as cloud seeding, has been used globally — across the Middle East, Europe, North Africa, China, and the US — to alleviate water shortages and stabilize natural freshwater supplies by increasing precipitation and streamflow. Despite its applications, cloud seeding remains controversial, with debates surrounding its effectiveness and the potential for international conflicts. This paper examines the efficacy of precipitation enhancement as a water management tool, using a nonlinear difference-in-differences framework with a Poisson Quasi Maximum Likelihood Estimator (QMLE) to analyze California’s extensive cloud seeding programs. Our findings indicate that these programs increase precipitation by 57% in targeted areas, with an average cost of $8.65 per acre-foot. However, the effectiveness of cloud seeding varies even among adjacent areas, suggesting that results from one location may not be applicable to another. Furthermore, we identify significant negative impacts on downwind watersheds, with estimated losses amounting to $49 million. This research provides guidance on the contexts in which cloud seeding programs may be viable, along with estimating potential deleterious impacts to neighboring communities.

Joint Estimation of Irrigation Adoption and Crop Choice in Ethiopia

Abstract: I examine the joint decisions of irrigation adoption and crop choice among smallholder farmers in Ethiopia. These decisions are crucial for enhancing agricultural productivity and food security in a context characterized by limited resources and weather variability. I develop a theoretical framework that captures the joint decision-making process, considering both profit maximization and subsistence needs faced by Ethiopian farmers. Using a nested logit model with data from the Ethiopian Living Standards Measurement Study-Integrated Survey on Agriculture (LSMS-ISA), the empirical analysis explores how factors like access to extension services, irrigation availability, and crop prices influence these choices. The results highlight the dominance of subsistence needs in crop selection, with a strong positive influence of household consumption share on crop choice. While extension services encourage cash crops, they discourage fruits, potentially due to perceived higher risk. Irrigation adoption remains limited, despite its potential to mitigate rainfall variability. This paper contributes to the literature by examining the combined effects of extension services and irrigation on crop choices in a water-scarce environment with limited resources. The findings inform the design of policies and interventions aimed at improving food security and farmer livelihoods by better accounting for the path-dependent decision-making process of smallholder farmers.

Economic Impacts of Climate Change on Agriculture and Water Resources in Morocco

Abstract: Climate change presents a major challenge with adverse impacts on sustainable economic development, especially in developing regions such as North Africa. Projected reduced rainfall with increased spatiotemporal irregularity will aggravate water scarcity in this region. Water resources shortages will particularly affect agriculture, the most climate-sensitive economic sector, in terms of agricultural production and incomes. This paper examines the impacts of climate change on water resources and on the agricultural value-added at a regional level in Morocco. Using a dynamic integrated hydro-agro- economic optimization model, I represent the relationship between conjunctive water use and agricultural production in the upstream part of the Oum-Rbia water basin, with a spatial water distribution network of water flows, balances and constraints. The model maximizes the total profit of water use by agricultural producers within the study region, which are primarily constrained by water availability. Simulations are conducted regarding projected changes in climatic and hydrologic variables. Results indicate a total gross margin reduction of 7%. In irrigated areas, production is roughly maintained at the same level as in the “business as usual” scenario but irrigation water quantities increase significantly, by up to 20%. Groundwater use buffers the increase in surface water shortages in agricultural perimeters that use surface water and groundwater conjunctively. Therefore, the groundwater head is reduced in all aquifers as a consequence of climate change. Finally, the economic value of water is greater under climate change scenario compared to “business as usual”, especially in irrigated areas that only use springs (+18%).