More than 250 people gathered in Reykjavik, Iceland, on October 12 and 13 for the Global Risk and Stabilization Summit, where discussions centered on the accelerating pace of climate change and the growing interest in large-scale Earth system interventions. The summit, organized in part by UCLA’s ESI Project, reflected mounting concern that current climate strategies may fall short as global temperatures rise past 1.5 degrees Celsius.
Earth’s Energy Imbalance Reaches Critical Levels
One of the most closely watched metrics at the summit was Earth’s energy imbalance, currently standing at 1.12 watts per square meter. This figure, drawn from the 2025 Indicators of Global Climate Change report, represents the difference between the energy Earth absorbs from the sun and the heat it radiates back into space. When this number is positive, heat accumulates in the land, oceans, and atmosphere, driving long-term climate shifts.
While greenhouse gas emissions are the primary driver of this imbalance, a second factor has emerged as equally alarming: Earth’s declining reflectivity. Known as “global dimming,” this phenomenon stems from fewer reflective aerosols, reduced cloud cover, and melting ice. Phil Duffy of Spark Climate Solutions noted that the warming caused by this loss of reflectivity is roughly equal to the cumulative effect of all human carbon dioxide emissions since 1750.
This realization has pushed some researchers to consider interventions like solar radiation modification, which aims to reflect more sunlight back into space. Such approaches remain highly controversial, but the doubling of energy imbalance since 2000 has made them harder to ignore. The World Meteorological Organization has highlighted this metric as a key indicator, signaling that the planet is storing more heat than at any point in recent history.
International Reports Stay Silent on Sunlight Reflection
In September, the United Nations Environment Programme released a report acknowledging that the long-term 1.5-degree Celsius target will be exceeded. While the report emphasized the need for carbon removal and adaptation, it made no mention of sunlight reflection or solar radiation modification, despite earlier engagement with the topic. A single reference to “geoengineering” appeared only in the context of ocean-based carbon dioxide removal.
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A recent story in Wired reflects concerns about geopolitical tensions generated from sunlight reflection technologies. Focused on a “war game” scenario by UK academics and Centre for Future Generations, the Wired report describes how tensions escalated during the simulation, especially between delegates from the U.S., Russia, and China.
Meanwhile, private investment in Earth system interventions is accelerating. In 2026, Rainmaker, a US-based company focused on cloud seeding, announced a $100 million Series B funding round. Founded in 2023, the company uses drones to deploy silver iodide, a substance long used in weather modification. Last year, Stardust Solutions secured $60 million for its proposed stratospheric aerosol injection technology, signaling growing confidence in the commercial viability of climate intervention services.
Research Capacity Expands as Private Investment Grows
Several countries have begun establishing dedicated research programs to study Earth system interventions, following the recognition that current climate strategies may not suffice. These initiatives focus on understanding potential risks, developing governance frameworks, and building technical expertise. Scientists involved emphasize the need for rigorous evaluation before any deployment consideration.
Climate Metrics and Political Silence Drive Expanding Interest in Earth System Interventions
Earth’s energy imbalance (EEI) has emerged as one of the most concerning yet under-discussed indicators of climate risk, alongside rising global temperatures, the ongoing El Niño event, and increasing atmospheric carbon dioxide levels. However, these approaches carry significant risks and uncertainties, highlighting gaps in the current climate strategy that focuses primarily on mitigation, adaptation, and carbon removal.