Tropical Agriculture Responses to Stratospheric Aerosol Intervention - Thesis

[Geoengineering News]

https://www.proquest.com/openview/e0444a33db1c589c5383acf49ad459d3/1?pq-origsite=gscholar&cbl=18750&diss=y

Authors: Nina Grant

Rutgers The State University of New Jersey, School of Graduate Studies, 2026

Abstract 

Climate change poses significant threats to global agriculture, impacting food quantity, quality, and safety. The world is far from meeting crucial climate targets, prompting the exploration of alternative strategies such as stratospheric aerosol intervention (SAI) to reduce the impacts, but its effect on agriculture is underexplored. This dissertation investigates the impacts of SAI on agricultural systems across the tropics. Utilizing a process-based crop model, CLM5crop, and 10 agroclimatic indices to diagnose growth-stage specific stressors, I find SAI leads to higher yields for rainfed rice and wheat in India, benefiting rainfed wheat the most with little impact on irrigated crops. Even without the use of SAI, adaptation strategies such as adjusting planting dates could offer partial relief under SSP2-4.5 if it is feasible to adjust established rice-wheat cropping systems. Next, I turned to two very popular, luxury crops, coffee and cocoa, to quantify for the first time how SAI would affect the production of tropical tree crops so dear to many around the world. To begin, I validated the crop model, ALMANAC, through a model intercomparison with the only other general-purpose, process-based model for cocoa and found good agreement between the models, both predicting increased cocoa yields under SSP5-8.5 once including the CO2 fertilization effect. However, ALMANAC excelled by producing realistic historical yields and similar future yields without any further postprocessing. When applying the model to a more realistic climate scenario, SSP2-4.5, I find coffee and cocoa yields decline by nearly 20% across all six models. SAI improves yields by~ 5% but cannot fully restore production to historical levels.

Source: ProQuest