SANTA CLARA COUNTY, Ca. – Luke Iseman and Andrew Song were not breaking any laws as they transported heavy tanks of sulfur dioxide in Song’s RV to release it into weather balloons.

Illegal? No. Controversial? Definitely.

On a warm Californian summer evening at the rural fringe of Silicon Valley, Song injected 3.8 pounds of gas into the balloon, while Iseman prepared a small Styrofoam box containing an altimeter and GPS module.

Then, Iseman connected the balloon’s neck to a helium tank, and it gradually inflated until it became a massive sphere, towering over him.

With a gentle thrust, he released the biodegradable latex balloon, watching it soar past a large oak tree into the clear evening sky.

At an altitude of over 14 miles, far above commercial air traffic, the balloon burst, dispersing its tiny and reflective gas payload into the stratosphere.

“Our aim,” Iseman stated, “is to lower global temperatures.”

The pair, both alumni of the prestigious tech incubator Y Combinator and having worked with multiple tech firms, are at the forefront of a global initiative aimed at combating climate change. Their venture is named Make Sunsets.

At a microscopic scale, they are mimicking what massive volcanoes have done for eons – sending lightly reflective gas into the stratosphere, which shields a tiny fraction of the Sun’s rays while also resulting in more vibrant sunsets.

In 1815, the eruption of Indonesia’s Mount Tambora reportedly cooled global temperatures by nearly 2 degrees due to the substantial amounts of ash and sulfur dioxide it released.

However, while Iseman and Song view these actions as initial steps towards climate salvation, long-standing climate scientists regard them as the potential trigger for a series of disastrous outcomes.

“I understand this isn’t the ideal approach – it should involve a global coalition of nations and NGOs, guided by exceptional scientists,” Iseman noted.

Sadly, he doesn’t expect that to happen in the near future, expressing frustration.

“Too many intelligent individuals are wrapped up in discussing political issues and alternative solutions while the planet is facing severe crises.”

He takes solace in the fact that their recent launch could offset annual carbon dioxide emissions equivalent to that of 1,745 tons, roughly the output of 380 vehicles.

‘It’s like giving morphine to the Earth’

For years, experts regarded climate engineering, or geoengineering, as a perilous concept steeped in science fiction.

Faced with proposals such as fertilizing oceans to trigger massive algae blooms and adding tons of sulfur dioxide to the stratosphere annually, they collectively reacted with alarm.

The Center for International Environmental Law classifies geoengineering as “dystopian technologies.” A manifesto signed by over 100 organizations worldwide advocates for a moratorium on all geoengineering field trials. The ETC Group, an activist organization, closely tracks geoengineering endeavors.

However, attitudes have started to shift recently: Some environmental organizations are now acknowledging that humanity may need to employ some strategies to cool the planet while simultaneously reducing carbon dioxide levels, recognizing these methods might be part of a broader strategy to cope with climate change.

“Environmental organizations are coming to the realization that if they don’t participate in this dialogue, they’ll miss the opportunity to influence what happens, so they need to engage,” said Katharine Ricke, a climate science professor at the University of California, San Diego.

Acting swiftly on geoengineering is crucial because critical decisions are looming sooner than anticipated, warned Wake Smith, a lecturer at Yale School of the Environment and author of “Pandora’s Toolbox: The Hopes and Hazards of Climate Intervention.”

“I fear the climate crisis is worse than you imagine,” he remarked. Although geoengineering, particularly the solar methods employed by Make Sunsets, is not a definitive solution, it could provide valuable time for the world to swiftly reduce carbon emissions. “It’s not a cure-all; it’s a pain reliever while we mend things,” he added.

Scientists are still debating the best analogy for geoengineering – is it akin to medication that allows Earth to recuperate, or is it comparable to narcotics that might harm it further?

Given this uncertainty, many global organizations remain convinced that experimenting with these technologies poses excessive risks.

And Nonetheless, in spite of their concerns, Make Sunsets continues to launch its balloons.

What are the risks?

Environmentalists are worried that geoengineering might lead to excessive or uneven cooling of the Earth. This could have detrimental effects on ecosystems, disturb global weather patterns, or even exacerbate global warming should a geoengineering project abruptly cease.

Such actions could trigger droughts, famines, and potentially conflict if they alter the rainfall patterns crucial for farming in regions like Asia and Africa. Furthermore, it could intensify storms or create scenarios where one nation diverts rainfall from another.

A concerning scenario, referred to as “termination shock” by scientists, implies that if large-scale solar geoengineering initiatives were implemented and then halted due to political disputes, it could lead to a rapid increase in temperatures.

If artificial cooling were removed suddenly, the Earth could warm up at an alarming rate, causing more chaos than gradual warming. Another possible outcome is that geoengineering could cool certain regions while leaving others warmer, intensifying global inequalities.

However, the precise future remains uncertain, leading many scientists and a growing number of conservationists to believe that exploring various methods of geoengineering is vital.

Additionally, there’s a persistent concern about “moral hazard”—the fear that the implementation of temporary solutions might convince the public that continuing to burn fossil fuels is acceptable, allowing the root of the issue to worsen.

A startup ventures into uncharted territory

Geoengineering comes in two varieties, one of which stirs more controversy than the other.

The first category is currently in action: initiatives aimed at removing excess carbon dioxide from the Earth’s atmosphere, which has been emitted since the Industrial Revolution.

The second variety teeters on more speculative ground—methods that some believe could have disastrous consequences.

This section of geoengineering focuses on finding alternative ways to artificially cool the Earth, aiming to counteract the destruction caused by greenhouse gases while transitioning away from fossil fuels.

The endeavors of Make Sunsets fall into this latter category.

There are concerns that if practices like those of Make Sunsets were implemented widely, ceasing them could lead to a spike in temperatures.

However, Iseman believes this is not highly concerning, as humans are already releasing significant amounts of sulfur dioxide through fossil fuel combustion annually. Unfortunately, this occurs in the lower atmosphere, where it affects human health without aiding in the reflection of solar radiation.

Make Sunsets, however, focuses on the stratosphere, where the gas can remain for about a year before returning to the surface.

They ensure to notify the Federal Aviation Administration before each launch with a Notice to Airmen, and they report each balloon launch to the National Oceanic and Atmospheric Administration.

By nightfall, the co-founders of the small startup will have launched two additional balloons at the request of about 600 customers, each of whom sees this not as a solution but as a temporary fix.

“One day, we hope this can slightly reduce temperatures, buying us precious time to phase out fossil fuel use,” Iseman expressed.

Financial interests reshape the landscape

Recent developments have prompted some experts to reassess their views on geoengineering: the entrance of for-profit companies such as Make Sunsets into an area that was previously dominated by academic research.

The questions surrounding regulation and accountability remain largely unresolved. Many scientists are opting to engage in the evolving situation rather than hope it will go away.

“The rise of startups in this space is genuinely concerning. The idea that profit-driven entities might drive technology deployment not for environmental benefits, but to satisfy investors is alarming,” Ricke stated.

The emergence of at least two companies seeking financial gain from geoengineering has intensified these anxieties. The small-scale Make Sunsets has around 600 customers purchasing its “cooling credits,” which fund its balloon launches.

On top of that, an Israeli American startup called Stardust Solutions has recently surfaced with $15 million in funding, making its intentions known to develop a solar geoengineering solution to sell to governments or international organizations.

As climate disasters unfold, “people’s perceptions of how the climate is changing.”

Daniele Visioni, a climate expert and professor at Cornell University, stated that the urgency of the climate situation is increasing.

While the Sierra Club expresses significant doubts, they concede that “it may be beneficial to begin researching some of these concepts,” remarked Patrick Drupp, the organization’s director of climate policy and advocacy.

The Natural Resources Defense Council is against the implementation of solar radiation mitigation measures and advocates for international guidelines before any experimental tests are conducted. However, they do endorse “restricted” outdoor experiments that have undergone independent assessment.

A critical question that arises is who has the authority to make decisions regarding these actions, according to Visioni.

“The stratosphere is largely unregulated territory,” he explained. “What prevents a private entity from sending up a balloon?”

Currently, it seems that there are no clear answers to this question.