Geoengineering and Security in the Indo-Pacific: Risks, Governance, and Strategic Imperatives

Geoengineering—the large-scale, deliberate modification of atmospheric and environmental conditions—is rapidly transitioning from theory to a potential tool in strategic and security planning.¹ As regional climate variability continues to impact infrastructure and security dynamics, particularly in the Indo-Pacific, security professionals are increasingly focused on its implications. The region faces mounting threats to human, political, economic, and environmental stability, making climate intervention an issue of strategic concern.

The United Nations’ Environmental Modification Convention (ENMOD)—formally the Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques—is the primary international agreement regulating geoengineering.² Its 48 signatories (16 unratified) and 30 additional state parties pledge “not to engage in military or any other hostile use of environmental modification techniques having widespread, long-lasting or severe effects.” Yet, the treaty’s focus on “hostile use” creates a loophole: any state can justify geoengineering by asserting peaceful intent. The treaty itself acknowledges this, stating that its provisions “shall not hinder the use of environmental modification techniques for peaceful purposes.”

The United Nations Environmental Program’s Provisions for Cooperation Between States in Weather Modification further affirms that states must conduct such activities to avoid harming other nations or areas beyond their jurisdiction.³ The Convention on Biological Diversity (CBD) contains provisions that may restrict certain geoengineering practices, and agencies such as the US Environmental Protection Agency (EPA) could regulate aspects of geoengineering domestically.⁴ However, meaningful enforcement mechanisms remain absent.

As geopolitical competition intensifies in the Indo-Pacific, the potential for unilateral geoengineering initiatives increases. Strategic priorities may lead states to pursue climate interventions without full consideration of regional implications, potentially impacting geopolitical stability. Combined with geoengineering’s technological accessibility, potential strategic implications, and evolving regulatory landscape, this reality necessitates prudent and adaptive governance. Without clear guardrails, the field will remain fertile ground for reckless experimentation, geopolitical friction, and conspiracy theories.

Effective geoengineering governance must embody:

• a US-driven strategy that aligns with allied interests and addresses key national security priorities;

• a clear commitment to strategic stability, responsible governance, and national interest protection through transparent and well-structured policies; and

• a forward-looking approach grounded in rigorous, evolving scientific evidence.

The choice is clear: establish responsible governance now, or face the destabilizing consequences of an unregulated climate intervention race.

Background, Rationale, and Underlying Concepts

History offers no shortage of lessons on how climate shifts have shaped the rise and fall of civilizations.⁵ From the deserts of Mesopotamia to the rainforests of Southeast Asia, prolonged changes in rainfall and temperature have played decisive roles in the collapse of societies such as the Sumerians, Khmers, and Mayans.⁶ Today, as nations confront evolving climate challenges, a critical question arises: Can we strategically manage the very forces that have long shaped our environment? The growing capability to alter Earth’s atmosphere and hydrosphere—whether regionally or on a global scale—has placed geoengineering at the center of policy and security debates.

Yet, shifts in climate patterns are influenced by broader human factors—including population growth, resource competition, industrial expansion, and evolving land use practices. Pollution, biodiversity loss, and disparities in economic and environmental conditions are all woven into the same tapestry.⁷ Geoengineering, therefore, is no silver bullet. At best, it is a tool—one with profound risks and uncertain rewards. To its proponents, it offers a way to restore stability, secure resources, and protect vulnerable populations. To its skeptics, it is an experiment in planetary-scale hubris. Either way, it is no longer a theoretical debate. It is a reality that warrants careful and strategic evaluation.

Types of Geoengineering

Geoengineering strategies fall into two primary categories:

• Solar Radiation Modification (SRM) – Techniques designed to reflect a portion of incoming solar radiation to influence temperature and atmospheric conditions.⁸

• Carbon Dioxide Removal (CDR) – Methods that extract carbon dioxide from the atmosphere and store it, mitigating its greenhouse effect.

A third, more experimental approach—pumping seawater onto snow-covered ice sheets—is also under investigation.

Solar Radiation Modification (SRM)

SRM methods seek to reduce global temperatures by reflecting sunlight before it can heat the planet. The four most commonly discussed techniques are: ⁹

1. Sunshades—This concept envisions placing massive reflectors in space to block a fraction of solar radiation before it reaches Earth. While theoretically effective, the engineering and logistical challenges render it infeasible with current technology.

2. Stratospheric Aerosol Injection (SAI)—By dispersing fine particles into the stratosphere, SAI would mimic the cooling effects of volcanic eruptions. Of all SRM methods, it is the most technologically viable, but scaling it to global levels and maintaining its effects over time present formidable challenges.

3. Marine Cloud Brightening (MCB)—This technique aims to increase the reflectivity of low-lying marine clouds by injecting aerosols, reducing heat absorption by the oceans. However, the underlying atmospheric processes remain poorly understood, limiting its feasibility.

4. Cirrus Cloud Thinning (CCT)—Unlike other SRM methods, CCT seeks to reduce the heat-trapping effects of cirrus clouds, allowing more thermal radiation to escape. As with MCB, scientific uncertainty over its effectiveness and risks hinders deployment.

Carbon Dioxide Removal (CDR)

CDR approaches fall into two broad categories: ocean-based and land-based methods. Given that oceans cover roughly 70 percent of the planet and can store vast amounts of carbon, many geoengineering efforts focus on marine environments.¹⁰

Ocean-Based CDR Methods:

1. Nutrient Fertilization – Introducing iron, phosphorus, or nitrogen into the ocean could stimulate phytoplankton growth, which would absorb CO₂ before sinking to the seafloor. The long-term effectiveness and ecological consequences remain uncertain.

2. Artificial Upwelling and Downwelling – Bringing nutrient-rich deep water to the surface could boost primary productivity, capturing more CO₂. Conversely, pushing carbon-rich surface waters to the depths might serve as a sequestration method.

3. Seaweed Cultivation – Large-scale farming of fast-growing seaweeds could trap carbon, which, upon decomposition, would be stored in ocean sediments.

4. Recovery of Ocean and Coastal Ecosystems – Restoring marine ecosystems, including seaweed forests and fish populations, could enhance carbon sequestration in coastal environments.

5. Ocean Alkalinity Enhancement – Adding alkaline minerals to seawater could increase its CO₂ absorption capacity.

6. Electrochemical Approaches – Using electrolysis to alter ocean water pH could either remove CO₂ or increase its long-term storage potential.

Land-Based CDR Methods:

1. Direct Carbon Capture and Storage (DCCS) – Emerging technologies can extract CO₂ directly from the air and store it underground or convert it into stable materials. The process remains costly and energy-intensive.

2. Mass Tree Planting (Afforestation) – Large-scale planting of trees could lock up CO₂ for decades, though this competes with land needed for agriculture.

3. Soil-Based Carbon Sequestration (Carbon Farming) – This method enhances soil’s ability to store carbon through regenerative agricultural techniques, but its global scalability is debated.

4. Biomass Accumulation – Growing fast-cycling plants, then burying them in sealed environments, could prevent carbon from re-entering the atmosphere. This approach remains largely untested at scale.

While these 14 methods represent the leading geoengineering proposals, none are currently ready for large-scale deployment. Each faces technological, logistical, economic, and regulatory challenges. Of all approaches, SAI and MCB stand out as the most immediately feasible, with estimated costs in the range of a few billion dollars.

Pumping Seawater onto Snow-Covered Ice Sheets

A separate, experimental geoengineering technique involves pumping seawater onto ice sheets to slow melting. The idea is that seawater would fill air pockets within the snow, increasing the shelf’s thermal conductivity, exposing the ice to the colder Arctic air, and triggering the growth of more ice on the underside of the ice. reducing heat absorption.¹¹ While theoretically promising, the energy required for large-scale pumping presents a major barrier to implementation.¹²

Geoengineering remains a field of scientific ambition and geopolitical uncertainty. If deployed without robust governance, its unintended consequences could rival the very problems it seeks to solve.

Context and Constraints

Geoengineering has never been purposefully tested on the global scale necessary to achieve meaningful climate intervention. Every proposed method interacts with at least one—if not multiple—of Earth’s five major systems: the atmosphere, hydrosphere, geosphere, cryosphere, and biosphere. Each of these is a vast, interwoven network of chemical, physical, and biological processes operating across spatial scales from nanometers to megameters and temporal scales of femtoseconds to millennia. Even in isolation, these systems are only partially understood, and their interactions are even less so. The complexity of geoengineering’s potential consequences is not merely theoretical; it is an unavoidable reality.

The fundamental problem is unintended consequences. In complex systems, interventions often trigger unpredictable and cascading effects. A simple illustration: oxygen, a reactive gas that supports combustion, and hydrogen, a volatile very light and explosive gas, combine to form water—a dense liquid that extinguishes fire. The interaction of Earth’s climate systems follows similarly counterintuitive logic. Modifying one aspect of the climate will inevitably affect others in ways that cannot be fully anticipated.

History provides a stark warning. Consider India’s vulture crisis. In the 1990s, the veterinary drug diclofenac, having become cheap and widely available, was commonly used on cattle. While promoting better growth in livestock, it is highly toxic to vultures. The unintended fallout? Vultures suffered a 95% population collapse.¹³ And without vultures to dispose of animal carcasses, rotting remains fueled an explosion of rats and feral dogs, spreading disease and contaminating water supplies. Rabies infections spiked, and an estimated 100,000 excess human deaths followed annually in affected regions. A similar dynamic unfolded in the United States, where the collapse of bat populations—critical for insect control—led to a surge in pesticide use and rising infant mortality rates. The lesson is clear: tinkering with natural systems produces consequences far beyond the intended effect.¹⁴

Now apply this principle to geoengineering. Even small-scale atmospheric interventions, like cloud seeding, have already caused regional disputes. When one country induces rainfall to alleviate drought, it can deprive neighboring regions of precipitation, worsening their own water crises. This is precisely the concern in South and Southeast Asia, where China’s massive “Sky River” project—a decades-long cloud-seeding effort—raises fears that monsoon patterns could be altered, with unknown consequences for agriculture across the region. While China technically remains within the bounds of the ENMOD Convention, the project’s opacity and potential violation of the “no harm” principle in international law underscore the dangers of unilateral climate intervention.¹⁵

Now, magnify these uncertainties a hundredfold. SAI, a proposed geoengineering technique, aims to cool the planet by dispersing reflective particles into the stratosphere. In theory, it mimics volcanic eruptions, which have historically led to temporary global cooling. But the atmospheric system is not static. The injected particles would spread unpredictably, falling into the lower atmosphere at different rates across regions. Some areas might cool. Others might warm. Precipitation patterns could shift in unforeseen ways, potentially triggering floods in some regions and droughts in others. Sulfate aerosols, one of the primary candidates for SAI, are known to cause acid rain, further compounding environmental risks. The core issue? No one can accurately predict who will bear the costs and who will reap the benefits.

In a sense, humanity has been conducting an uncontrolled geoengineering experiment for centuries. Industrialization, deforestation, and urbanization have already altered climate systems. The rapid release of greenhouse gases has forced the planet into a state of accelerating change. Yet, we have operated largely in ignorance of these interdependencies. Our history suggests a pattern of short-term thinking and reckless exploitation—often at the expense of indigenous populations, natural ecosystems, and long-term sustainability. Geoengineering risks repeating this pattern on a vastly larger scale.

Still, there is precedent for cooperative management of shared environmental resources. The Indus Waters Treaty (IWT), a rare example of successful transboundary water governance, has survived multiple conflicts between India and Pakistan.¹⁶ Its durability stems from clear, enforceable agreements and the high cost of violations—reneging on the treaty would be tantamount to an act of war. Yet even this model has limitations: the IWT lacks provisions for evolving climate realities and does not mandate data-sharing, critical oversights in a rapidly changing and interconnected world.¹⁷

Elsewhere, treaties have failed to prevent kinetic conflict over shared rivers.¹⁸ Human history suggests that nations are notoriously poor at managing common resources, particularly when access to water, food, and energy is at stake. If states struggle to share rivers, can we realistically expect global cooperation on geoengineering—a technology that affects the atmosphere and oceans on which all nations depend? The answer is, at best, uncertain.

For the Indo-Pacific, geoengineering’s maritime consequences are particularly troubling. While most discussions focus on terrestrial impacts, ocean-based carbon dioxide removal (CDR) could disrupt marine ecosystems at a massive scale. This is more than an environmental concern; it threatens regional food security, economic stability, and geopolitical balance. Altering ocean chemistry could destabilize fisheries, shift territorial claims, and spark diplomatic disputes—particularly among nations already engaged in maritime tensions.

Rising sea levels add another layer of complexity. Even under the most ambitious scenarios, geoengineering would not significantly slow sea level rise for decades—a sobering reality for Indo-Pacific nations already struggling with coastal erosion and disappearing islands. Efforts to codify governance for marine geoengineering are underway, but they face immense political resistance. In the absence of a robust regulatory framework, unilateral action—driven by desperation, strategic interest, or economic incentives—remains a serious risk.¹⁹

Specific Indo-Pacific Regional Security Implications

As climate variability continues to impact the Indo-Pacific, regional leaders may encounter growing pressure to respond. Some governments, operating with greater strategic autonomy, may be more inclined to consider unilateral SRM efforts.²⁰

China provides a case study in state-driven environmental intervention. For centuries, its rulers have reshaped landscapes—constructing vast canal systems to redistribute water and, in the modern era, erecting 87,000 dams with little regard for downstream nations. This mindset—that nature is to be controlled rather than accommodated—suggests that China could be an early adopter of SAI or MCB. Its Sky River cloud-seeding project, already operational on the Tibetan Plateau, reinforces concerns about unilateral geoengineering with regional consequences.

Other Indo-Pacific states may follow suit. India, facing lethal heat waves and expanding deserts, could seek to “turn down the thermostat” to protect its population and agricultural base. Pakistan, dependent on the Indus River, might attempt to increase rainfall through SRM, further inflaming tensions with India. Indonesia and the Philippines, battered by intensifying typhoons, might see solar geoengineering as a means of moderating ocean temperatures.

Each of these scenarios carries geopolitical risk. Geoengineering alters weather patterns indiscriminately, meaning one nation’s solution could trigger droughts, floods, or climatic disruptions for its neighbors. Such unintended consequences would inevitably fuel diplomatic disputes, economic instability, and strategic realignments. While major powers are the most likely to pursue SRM, smaller states could also take matters into their own hands—setting the stage for a fragmented and chaotic climate intervention race.

The unpredictability of geoengineering’s regional impacts, coupled with the ENMOD Convention’s prohibitions on hostile environmental modification, makes it unlikely that these technologies will be explicitly weaponized in the near future.²¹ However, their military implications are far from benign. The challenge is not whether geoengineering will be deployed as a tool of war, but rather how states will respond to its unintended strategic consequences. The emphasis will be on reaction and mitigation—preventing, countering, or containing an adversary’s unilateral climate intervention rather than initiating geoengineering as an offensive capability.

This raises a host of complex, unresolved questions. What level of geoengineering deployment—by whom, under what circumstances—might trigger a kinetic response? Could a nation justify military action if it believed another state’s climate modification efforts were harming its agriculture, water supply, or energy production? What nonmilitary deterrence measures exist? Would diplomatic pressure, sanctions, or cyber interventions be sufficient to stop a state from altering the atmosphere?

Domain awareness will be crucial. Some geoengineering efforts, such as ground-based cloud-seeding stations like China’s Sky River project, leave physical footprints and are relatively easy to detect. Others, such as SAI deployed via aircraft, are far more difficult to track. Satellites, aerial reconnaissance, and atmospheric monitoring networks can provide intelligence, but the Indo-Pacific’s vast geography and limited regional monitoring infrastructure create gaps that could allow significant geoengineering efforts to proceed unobserved.

Even if a deployment is detected, attribution presents a serious challenge. In some cases, identifying a nation engaged in SRM may be straightforward, but proving causation of specific weather effects is another matter entirely. Did an anomalous drought, flood, or hurricane result from a country’s geoengineering efforts—or was it simply an expression of natural climate variability? The complexities of atmospheric dynamics make definitive attribution nearly impossible beyond short-term, geographically localized events. The longer the timeframe and the greater the distance, the murkier the link. This uncertainty provides plausible deniability, shielding states from accountability—much like China’s Sky River project, which has drawn regional suspicion but remains difficult to challenge under international law.

Regional governance solutions remain elusive. No formal mechanisms exist to prevent or punish a state for engaging in geoengineering. A smaller nation might be coerced into abandoning an SRM effort through diplomatic isolation or economic sanctions, but it is unlikely that collective action could dissuade a major power—such as China, India, or Pakistan—from pursuing climate intervention if it deemed it vital to its national security. This underscores the importance of establishing clear, practicable international governance—an objective that remains challenging given current geopolitical dynamics.

Strategic Considerations for Geoengineering Research and Governance

Despite its unknowns, unintended consequences, and the disproportionate risks it poses to vulnerable populations, geoengineering is emerging as a potential tool for strategic advantage in great-power competition. Its appeal lies in its apparent simplicity: reflect sunlight, lower temperatures, and modify climate conditions. This reductionist view, however, ignores the profound complexity of Earth’s interconnected systems.²²

The growing demand for solutions stems from multiple factors, including prolonged droughts, shifting rainfall patterns, and freshwater shortages. Population growth, industrial expansion, and land-use changes further complicate these challenges. As policymakers weigh their options, geoengineering presents both opportunities and risks, raising important questions about feasibility, effectiveness, and oversight.

A key concern is the risk of unilateral action—the possibility that a single state, corporation, or well-resourced entity could deploy geoengineering technology without broader coordination. Unlike other strategic capabilities, certain geoengineering methods, such as SAI and MCB, have relatively low barriers to entry, making them accessible to a range of actors. This presents significant security and governance challenges. How would affected nations respond if another actor altered atmospheric conditions in ways that disrupted regional stability?

Given these considerations, the need for well-structured governance frameworks is evident. Without clear policies and agreed-upon mechanisms for transparency, verification, and dispute resolution, geoengineering risks becoming a source of geopolitical friction rather than a stabilizing tool. Ensuring that such technologies are developed and assessed with appropriate safeguards will be essential in preventing unintended consequences and maintaining regional stability.²³

A fundamental starting point in any discussion of geoengineering is recognizing that the Earth’s atmosphere and oceans are shared resources. Every nation, every community, and every individual depends on clean air and access to water. Given this reality, unilateral climate interventions raise serious ethical and strategic concerns. No state or entity should have the unchecked ability to alter atmospheric or oceanic conditions in ways that could negatively impact others.²⁴

The potential for unintended consequences is particularly troubling. While some advocate geoengineering as a tool to mitigate environmental challenges, its deployment could exacerbate existing disparities in resource access and environmental conditions.²⁵ The World Health Organization reports that 99 percent of the global population breathes air that fails to meet basic health standards, and between one-quarter and one-half of the world lacks access to clean drinking water.²⁶ Introducing large-scale climate interventions without rigorous oversight risks further complicating these challenges rather than solving them.

Beyond the direct risks, geoengineering could serve as a pretext for delaying or avoiding industrial and agricultural modernization. If cooling the planet is as simple as injecting aerosols into the atmosphere, some may ask, why invest in cleaner energy, more efficient manufacturing, or sustainable resource management? Given historical trends in industrial adaptation to environmental regulations, there is a possibility that geoengineering could be viewed as a replacement rather than a complement for emissions reduction efforts.

Also, certain geoengineering methods, such as SAI, require continuous, long-term implementation to maintain their effects. If abruptly halted, they could trigger rapid and severe climate shifts, compounding rather than alleviating environmental instability. Given the realities of longer-term political and economic dynamics, the risks of a sudden shift are nontrivial.

Additionally, while some debate the broader impacts of atmospheric carbon, ocean acidification remains a well-documented phenomenon with serious ecological consequences. The decline of plankton populations, which support marine food chains and global fisheries, directly threatens food security for billions. The argument for reducing atmospheric carbon emissions is not solely about temperature—it is also about maintaining the integrity of critical natural systems.

Finally, the lack of enforceable regulations governing geoengineering is itself a major concern. At present, any sufficiently resourced state, organization, or private actor could pursue climate modification with little to no accountability. Without clear legal frameworks, mechanisms for oversight, or agreements on acceptable use, nothing prevents a small group from unilaterally initiating atmospheric interventions that could have global repercussions. In the absence of responsible governance, geoengineering remains a high-risk proposition—one that could introduce more problems than it solves.

Uncertainty and unintended consequences are inherent in scientific and technological progress. Whether viewed as an unavoidable challenge or a necessary risk, innovation always carries unknowns. That, however, has never been a reason to halt progress. Advancements in science and technology have undeniably improved human life—extending lifespans, enhancing health and nutrition, and driving economic and industrial development. The question is not whether to pursue new technologies but how to manage them responsibly.

The urgency of establishing clear guidelines for geoengineering is underscored by recent developments. While several proposed US field tests have been canceled in recent years, the UK government has announced funding for small-scale outdoor geoengineering experiments.²⁷ These projects include safeguards and oversight, but their very existence highlights the growing international interest in climate modification technologies. If nations are moving forward with research, the absence of agreed-upon governance frameworks becomes even more concerning. Without clear regulations, the risks of uncoordinated or unilateral geoengineering efforts grow exponentially.

Establishing effective governance for solar geoengineering presents significant challenges. Divergent national priorities—ranging from economic interests and industrial capabilities to political structures and strategic considerations—complicate efforts to develop a cohesive framework. While some nations emphasize technological innovation and intellectual property protections, others focus on legal and geopolitical implications. The risk of unilateral deployment by a single actor further complicates regulatory efforts, raising concerns about oversight, accountability, and the potential for unintended consequences.

Despite multiple attempts to outline governance principles, there is little consensus on enforceable mechanisms. Beyond broad, high-level agreements, nations remain divided on the specifics of oversight, research permissions, and potential deployment. As interest in geoengineering grows, so too does the need for a realistic, enforceable framework—one that balances scientific advancement with geopolitical stability.

Conclusion

Geoengineering is no longer a distant possibility—it is a developing reality. Ignoring it is not an option. There are two fundamental reasons why advancing knowledge in this field is critical. First, if geoengineering is deployed unilaterally by a single nation, organization, or even a small group of individuals, governments must be prepared to respond effectively. Second, if the global community ultimately decides to pursue geoengineering in a coordinated manner, decision-makers must have a clear understanding of its mechanisms, risks, and strategic implications. The notion that these technologies will simply be set aside or that a universal moratorium will hold indefinitely is unrealistic.

For military planners and security professionals, geoengineering governance remains an unresolved challenge. While the need for strategic guidelines is clear, efforts to develop enforceable frameworks have stalled amid geopolitical divisions. The complexities of oversight, verification, and international cooperation remain formidable. However, some core principles have begun to emerge.

First, geoengineering research alone is insufficient.²⁸ Governance must evolve alongside technological development.²⁹ As outlined by the National Academies of Sciences, Engineering, and Medicine, any advancement in solar geoengineering must be pursued within a structured framework—one that accounts for scientific, technological, and geopolitical factors. Without a deliberate and measured approach, the world risks being caught off guard by the realities of geoengineering rather than prepared to shape its responsible use.³⁰

Second, any viable geoengineering framework must address key areas, including:³¹

• interdisciplinary collaboration among natural scientists, social scientists, and international relations experts;

• cultural and societal assessments by anthropologists and sociologists to track evolving public perceptions and the decision-making frameworks of political leaders; and

• strategic analysis through game theory, behavioral modeling, and numerical simulations to anticipate geopolitical and economic responses.

Third, a parallel framework has been proposed for ocean-based CDR technologies.³² Effective geoengineering research and governance should incorporate:

• a US-led approach that prioritizes national security while coordinating with allies to address strategic concerns;

• a clear, principles-based structure that ensures transparency, ethical oversight, and accountability; and

• a forward-looking strategy based on continuous scientific evaluation and adaptive policy making.

For the Indo-Pacific, where security and environmental stability are deeply intertwined, geoengineering cannot remain an abstract academic debate. Its research, development, deployment, and regulation must be actively discussed at the highest levels of policymaking and defense planning. Without clear governance, the risks—both strategic and environmental—will only grow. ♦

Dr. Ethan Allen

Dr. Allen is a professor at the Daniel K. Inouye Asia-Pacific Center for Security Studies (DKI APCSS), specializing in science, technology, and security issues in the Indo-Pacific. He holds a doctorate in systems and integrative biology (neuroscience) from the University of Oregon, with postdoctoral research at the University of Texas at Austin. Before joining DKI APCSS, he led STEM education and water security initiatives across the Pacific, including National Science Foundation-funded projects on drinking water conservation and improvement. His current research focuses on the intersection of environmental change, technological innovation, and regional security dynamics.

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