Proposed Annual Solar Geoengineering IPCC Pathways as CO2 Goals Falter: ECS Verified Feedback/Loops Critical by 2075-2125—Preprint

[Geoengineering News]

https://www.researchgate.net/publication/392529593_Proposed_Annual_Solar_Geoengineering_IPCC_Pathways_as_CO2_Goals_Falter_ECS_Verified_FeedbackLoops_Critical_by_2075-2125

Author

Alec Feinberg

June 2025

Abstract

Feedback (and loop) trend contributions are projected, estimating increases from current 52% (27%) to 75% (56%) of global warming across RCP scenarios without the aid of Solar Geoengineering (SG). Results indicate there is not enough time and capability to realistically achieve required CO2 reduction goals. Feedback projections were verified with 3 (of 7) trend data points including IPCC AR7 ECS 3oC likely value and the 1870 no feedback reference point indicating reasonable estimates. Therefore, initial mild Annual Solar Geoengineering Pathways (ASGPs) are proposed to include Earth Brightening, SAI in Arctic regions, and feasible L1 Space Sunshades to help avert GW feedback loop risks, providing more CO2 mitigation time. This ASGP proposal attempts to address IPCC AR6 SG concerns. RCPCritical, defined as when feedback loops exceed 50%, which would dominate global warming, is estimated to occur between 2075 and 2125 without ASGPs. RCPCritical is a red flag point, where we may have an inability to reverse GW trends with eventual tipping points’ risks. As of 2024, RCP 2.6 CO2 goals have significantly failed, threatening RCP4.5 and RCP6 goals. The alternative mitigating aid, SG, has been derided by many climate scholars, yet SG is 62% more efficient than carbon dioxide removal (CDR), is timely, is challenging but feasible, and condenses out water vapor GHG quickly. In 2024 the net CO2 was +23 GtCO2 (3ppm) with forest losses of about +4GtCO2 exceeding CDR afforestation/reforestation CDR gains of only -2 GtCO2. Such trends make RCPs goals realistically unachievable. Numerous obstacles create large sustainability risks. Because of unsupported scholars, there are currently no significant SG efforts, which take years to implement. Unfortunately, the opposite problem of critical worldwide abuse is occurring with dark roads, roofs, cars, and building sides, a form of negative SG. Furthermore, recent worldwide ground-based urbanization measurements found a significant global warming contribution of about 13%, contradicting satellite albedo urbanization measurements assessed here as highly unreliable and misleading scholars. Further, ERF urbanization heat flux modeling supports ground-based and not satellite results. This further justifies the critical need for urbanization Earth brightening in heat-stressed cities. International climate strategies including AR7 and the Paris Accord, urgently should include the mild ASGPs proposed (that addresses previous SG AR6 concerns) for sustainability to avoid reaching RCPCritical. There is a vital need for space agencies around the world to contribute to all ASGPs, to achieve sustainability.

Source: ResearchGate