A framework for understanding and narrowing uncertainties for Solar Radiation Modification modeling experiments - Preprint

[Geoengineering News]

https://essopenarchive.org/doi/abs/10.22541/essoar.15006778/v1

Authors: Dr. Daniele Visioni, Dr. Ben Kravitz, Prof. Douglas G MacMartin, Mr. Timofei Sukhodolov, Gabriel Chiodo, and Mr. Sandro Vattioni

30 July 2026

https://doi.org/10.22541/essoar.15006778/v1

Abstract

A clear conceptualization of what constitutes an uncertainty, and what its sources are, is crucial to understanding how they can be constrained. For Solar Radiation Modification (SRM), this is important as we grapple with deciding how (and if) to pursue research programs capable of narrowing its related uncertainties. We propose to separate &ldquo;uncertainty&rdquo; for SRM evaluation into the following macro-categories: storyline uncertainty, which includes scenario, target and strategy uncertainty; and physical uncertainty, which can be investigated through the exploration of inter-model SRM uncertainty (Earth system processes specific to SRM) and inter-model climate uncertainty (underlying uncertainty in the representation of climatic processes). <br /><br />We apply our framework to model simulations of stratospheric aerosol injections (SAI) and find that: 1) in the same models, inter-model uncertainties due to increases in temperatures of ~2&ordm;C are larger than inter-model uncertainties from SAI aimed at avoiding that increase, independently of spatial aggregation considered, (68% larger for temperatures, 23% larger for precipitation); 2) inter-model SAI uncertainties are strongly driven by uncertainties in the simulation of aerosols and their transport, including their downstream impacts, and we conclude that resolving such uncertainties has the potential to reduce overall uncertainties by over 60%; 3) uncertainties related to the deployment of different aerosols in one model are small compared to inter-model SRM uncertainties; 4) for different strategies and scenarios with one model, we conclude that, while globally temperature and precipitation are overwhelmingly driven by target uncertainty, regionally the strategy uncertainty can be a relevant portion of the overall storyline uncertainty.

Source: ESS Open Archive