Roadmap toward a planetary sunshade for space-based solar geoengineering

[Geoengineering News]

https://www.sciencedirect.com/science/article/pii/S0273117726004503

Authors: Catello Leonardo Matonti, Marina Coco, Chantal Cappelletti, Bruce Chesley, Christer Fuglesang, Giuseppe Governale

April 2026

https://doi.org/10.1016/j.asr.2026.04.007

Highlights

•A roadmap for a space-based solar geoengineering program is proposed, aiming for a reversible Planetary Sunshade System to mitigate global warming.

•A phased deployment strategy is outlined, starting with precursor missions over the next two decades, followed by an initial operational phase by 2040 and full deployment by 2080.

•This roadmap includes the main aspects to address the full development, considering the involved technologies, launchers, and swarm logistics at the photo-gravitational L1 point.

•Political and regulatory challenges are considered, emphasizing the need for international cooperation, governance frameworks, and public acceptance.

Abstract

Climate change mitigation may require transformative strategies beyond emission reduction. This paper introduces a technology roadmap for developing a Planetary Sunshade System: a space-based solar geoengineering concept designed for reversible Solar Radiation Management. The proposed roadmap is a structured, multi-phase plan from early technology demonstrations to full deployment at the Sun–Earth/Moon Center of Mass photo-gravitational Lagrange point. The roadmap addresses critical aspects such as solar-sail design, in-space assembly, swarm logistics, and launch infrastructure, while outlining milestones for initial operations by 2040 and full capability by 2080. By integrating technological, logistical, and programmatic considerations, this roadmap serves as a framework for assessing feasibility and guiding international collaboration on space-based climate interventions.

Source: ScienceDirect