Simulation of the Effects of SO<sub>2</sub> Injection into the Stratosphere on Precipitation and Temperature Regimes in the Sahel, West Africa

To address global warming and its impact on the Sahel, particularly rising temperatures and changing precipitation patterns, this study explores Solar Radiation Management (SRM) through stratospheric aerosol injection (SAI). Using the IPSL-CM5A-LR model, we simulate the effects of SO2 injection on temperature and precipitation. We analyze data across three scenarios: historical greenhouse gas concentrations, RCP4.5 without SO2 injection, and RCP4.5 combined with SO2 geoengineering (G3). Climate data for two future periods (2020-2050 and 2050-2080) are compared to historical data (1950-2005) to assess seasonal and spatial variations in climate parameters. This study aims to evaluate the impact of SAI on temperature and precipitation in the Sahel, comparing historical data with RCP4.5 and SAI scenarios. It seeks to determine SAI’s effectiveness in mitigating warming and identify potential side effects on the region’s climate from 2020 to 2080. Results indicate that stratospheric SO2 injection in the Sahel moderates seasonal temperatures, sustaining reductions through 2050-2080. The injection stabilizes temperatures, especially in summer, potentially mitigating heat stress during the hot season. However, SAI exhibits varied impacts on precipitation patterns across seasons. While it enhances rainfall in June and July, it generally reduces precipitation intensity in May, June, and August. These effects underscore the complex interplay between SAI and regional climate dynamics. Overall, stratospheric SO2 injection emerges as a promising tool for climate mitigation in the Sahel, offering both opportunities and challenges that warrant further investigation as global efforts to address climate change intensify. Understanding these dynamics is crucial for informed decision-making regarding climate intervention strategies in vulnerable regions like the Sahel.