[Reading Science] Can 'Geoengineering' Be the 'Magic' That Saves the Earth?

'Uncontrollable Technology' vs. 'Planetary Design Technology'
Changing Earth's Climate with a Stratospheric Nuclear Explosion?
Governments and Companies Move Beyond Theory to Direct Experimentation
Removing Billions of Tons of Carbon Annually...

'Geoengineering,' once confined to the realm of imagination in movies and documentaries, is now being discussed as a matter of science and policy in the real world.

Geoengineering refers to large-scale technological attempts to intervene in Earth's systems-such as the atmosphere, oceans, and glaciers-to control the climate in response to climate change. Typical methods include reflecting sunlight from space or removing carbon dioxide from the atmosphere. It is also a product of a new philosophy of technology, as it involves humans viewing the entire planet as a manageable system and seeking to intervene directly.

Movies Dealing with Geoengineering.

'Uncontrollable Technology' vs. 'Planetary Design Technology'

This concept did not originate solely as an extension of science and technology. The imagination of 'designing a planet,' repeatedly depicted in films and novels, served as an important backdrop. Director Bong Joon-ho's film (2013) tells the story of humanity on the brink of extinction after a cooling agent is sprayed into the stratosphere, triggering a new ice age. Dean Devlin's (2017) depicts an attempt to control Earth's climate through a satellite network, which leads to catastrophe due to malfunction and political misuse. In this way, geoengineering has often been portrayed in popular culture as an 'uncontrollable technology.'

However, there are also works with a stronger scientific foundation. The National Geographic documentary (2016) depicts the process of terraforming Mars based on actual scientific research. The same goes for the film (2015). The idea of altering Mars's atmosphere and creating ecosystems using bacteria and plants is not mere fantasy, but closely aligns with the concept of 'terraforming,' which the scientific community has seriously considered for decades.

Changing Earth's Climate with a Stratospheric Nuclear Explosion?

In the 1970s, NASA studied plans to install massive reflectors at Mars's poles or to disperse specific microorganisms to alter the atmosphere. Some scientists even proposed radical ideas such as detonating nuclear devices in the stratosphere to change Earth's climate.

During the Cold War, the United States and the Soviet Union actually conducted weather modification experiments. During the Vietnam War, the U.S. military attempted to block enemy supply routes by inducing artificial rainfall in 'Operation Popeye.' Such efforts ultimately led to the 1977 Environmental Modification Convention (ENMOD), which banned the military use of environmental modification techniques.

In the 1980s, the 'Nuclear Winter' scenario emerged in academia. Calculations suggested that dust and smoke from a large-scale nuclear war could block sunlight and rapidly lower Earth's temperature. Even with the scientific capabilities of the time, it became clear that artificial changes to Earth's environment were within the realm of possibility. This demonstrated how sensitive and vulnerable humanity is to artificial manipulation of the climate system.

Governments and Companies Move Beyond Theory to Direct Experimentation

Although not always implemented, the idea of viewing and designing Earth as a system has been latent in the scientific community for over half a century. Against this historical backdrop, geoengineering has reemerged in the 21st century as the world faces a climate crisis.

Today, geoengineering is no longer just theoretical. Direct experiments are being conducted on Earth. The Advanced Research and Invention Agency (ARIA), a UK government research institute, has been conducting 'Exploring Climate Cooling' experiments since 2025. These experiments, with a total budget of 56.8 million pounds (approximately 100 billion won), include injecting aerosols into the stratosphere, dispersing salt particles over the ocean to brighten clouds, and spreading highly reflective particles over Arctic sea ice to slow melting. This is why some describe it as "actually touching Earth's systems."

However, ARIA's experiments are strictly managed on a small scale, for limited periods, and with the ability to restore conditions to their original state, in order to collect real-world data that cannot be obtained through modeling or laboratory experiments alone. This reflects an awareness of the risks of geoengineering, with a focus on early-stage research to resolve scientific uncertainties rather than on full-scale technological deployment.

Removing Billions of Tons of Carbon Annually... Profiting from Carbon Credits?

Private companies are also entering the field. U.S. startup Equatic and Canadian company Planetary Technologies are conducting ocean alkalinity enhancement (OAE) trials, in which alkaline substances are added to seawater to mitigate ocean acidification and simultaneously absorb atmospheric carbon dioxide.

U.S. company Vesta is testing a method in 'Project Vesta' that involves crushing the mineral olivine and spreading it on beaches, where it reacts with waves to draw carbon dioxide into seawater. These companies are even planning to generate revenue through carbon credit trading. They claim that it is possible to remove billions of tons of carbon annually.

One of the most prominent geoengineering technologies is stratospheric aerosol injection (SAI), which involves spraying particles such as sulfur dioxide into the stratosphere to reflect some sunlight. This idea was inspired by the temporary global cooling that occurred after the 1991 eruption of Mount Pinatubo in the Philippines.

Placing Reflectors Between the Sun and Earth: Cost and Ecosystem Destruction Concerns

Various technologies are being considered under the broad category of solar radiation management (SRM), including the idea of installing massive reflectors in Earth's orbit. In 2006, American astronomer Roger Angel proposed placing tens of trillions of thin reflectors at the Lagrange point between the Sun and Earth. Other proposals have included installing giant mirrors over deserts or oceans to reflect sunlight. However, the enormous cost-amounting to several trillion won-and concerns about ecosystem destruction make implementation unlikely.

Technologies aimed at directly removing carbon are also being actively discussed. These include direct air capture (DAC), which absorbs carbon dioxide directly from the atmosphere, and ocean fertilization, which involves dispersing iron into the ocean to stimulate plankton growth. In fact, in 2012, a private experiment was conducted off the coast of British Columbia, Canada, where 100 tons of iron sulfate were dispersed. While plankton populations exploded, concerns arose that this process depleted oxygen, created ocean 'dead zones,' and disrupted the food chain. There was also criticism that it violated international agreements. Although the technical feasibility was confirmed, the risks became equally apparent.

The potential applications of geoengineering are not limited to addressing the climate crisis. Ideas such as reducing sulfur and nitrogen oxides, controlling ocean circulation, and purifying the atmosphere have also been consistently suggested.

Potential for International Conflict and the Risk of Moral Hazard

The effects and risks of geoengineering technologies coexist. The Intergovernmental Panel on Climate Change (IPCC) has pointed out that while geoengineering can effectively lower temperatures in the short term, it may also cause imbalances in precipitation patterns, leading to droughts and floods. If a particular country implements these technologies unilaterally, it could cause harm to other nations, raising the possibility of international conflict. The more effective the technology, the greater the risk of 'moral hazard,' where countries delay efforts to reduce greenhouse gas emissions. There is also concern about 'technological lock-in,' meaning that once started, it may be difficult to stop. If funding runs out or political reasons force a halt, Earth's temperature could rise rapidly, causing irreversible damage.

Kim Jinsu, a professor in the Department of Civil and Environmental Engineering at KAIST, said, "Regional imbalances are inevitable, and climate models themselves contain uncertainties, so policy decisions must be made cautiously." He added, "Scientific feasibility must be accompanied by international governance and ethical discussions."

Geoengineering could be humanity's 'last card' to overcome the climate crisis. However, if misused, it could also bring about a new crisis. The key issue is not the technology itself, but who uses it, for what purpose, and with what responsibility. Whether the idea of designing Earth through technology will save humanity or lead to disaster remains an open question.