The Short Version
Bill Gates did fund solar geoengineering research, including Harvard's SCoPEx project and earlier cloud-whitening concepts. This is well-documented by credible outlets. However, these experiments were designed to study solar radiation management for global cooling and model refinement — not to control rainfall. Altered precipitation patterns are a recognized potential side effect, not the stated goal. SCoPEx was canceled in March 2024. The claim conflates a foreseeable risk with deliberate intent, making it a partial truth wrapped in a distorting frame.