Main points
- Startup Stardust Solutions has received $60 million in investment to develop particles that will reflect sunlight back into space to reduce global warming.
- The idea has raised concerns about possible unforeseen risks and a lack of transparency in the composition of the particles, which could lead to environmental and geopolitical problems.
Stardust Solutions wants to stop warming / Collage of Channel 24/Unsplash
Humanity is on the verge of a technological experiment of unprecedented scale. A private startup has attracted huge investments to implement an idea that previously seemed like a science fiction scenario. It is about a radical method of combating climate change that affects the entire atmosphere of the Earth.
How will a new development help stop warming?
Israeli-American startup Stardust Solutions announced that it will raise $60 million in investment in 2025, a record amount for the solar geoengineering industry. The main idea of the project is to spray special microscopic particles into the Earth’s stratosphere that will reflect some of the sunlight back into space. The amount of reflected light will be imperceptible to humans – there will be no darkness. However, this will be enough to reduce the amount of solar heat to acceptable limits, writes Futurism.
This method essentially replicates the effect of powerful volcanic eruptions, which naturally cool the planet's surface. However, unlike volcanic ash and sulfur aerosols, which cause acid rain and destroy the ozone layer, Stardust's developers claim to have created a unique, environmentally neutral substance.
The company's head and former nuclear physicist Janaj Jedwab claims that the new particle resembles ordinary flour in terms of safety, but it can be produced on an industrial scale – in millions of tons.
The company has already prepared a 14-page safety testing plan and a list of guidelines for its activities. However, the composition of the particle itself remains a trade secret, which they promise to reveal only in the coming months.
This secrecy is causing concern in the scientific community. Geoengineering expert Cynthia Scharf notes that no independent experts know exactly what substances the private entity intends to release into the atmosphere for profit.
Scientists have previously proposed spraying sulfur dioxide, chalk, and even diamond dust, so it's clear that this would have to be something completely new.
Not everyone likes solar geoengineering
Solar geoengineering has a history of fierce resistance. In 2023, Mexico banned such experiments entirely after another startup launched a balloon filled with sulfur dioxide. It was later discovered that the substance was only a few grams, which was not enough to have any effect (volcanoes typically emit 500 to 10,000 tons of sulfur dioxide per day without any noticeable effects).
A similar fate befell a Harvard University project in 2021, which was shut down before testing began due to protests. Stardust Solutions is trying to do things differently, bringing in lobbyists to negotiate with the US Congress and emphasizing the need for government regulation.
Yanai Jedwab compares his company to pharmaceutical giants: they create drugs with private funds, but release them to the market only under the strict supervision of regulatory authorities.
Why are scientists and governments afraid of solar geoengineering?
Scientists and governments in many countries have expressed serious concerns about solar geoengineering (particularly the spraying of aerosols into the stratosphere) due to a number of unforeseen risks to the planet. While this technology could theoretically reduce global temperatures quickly, it does not eliminate the cause of warming – the accumulation of greenhouse gases.
The main reasons for doubts:
- Risk of “shutdown shock.” If the particle spraying system were to be suddenly stopped (due to war, terrorism, or technical failure), the temperature on the planet could jump by several degrees in a matter of years, which would be catastrophic for ecosystems.
- Changing rainfall cycles. Modeling shows that the reflection of sunlight could disrupt global monsoons and rainfall cycles, leading to droughts in vulnerable regions such as Africa and South Asia and threatening food security.
- Ozone depletion. The use of sulfate aerosols can slow the recovery of the ozone layer or even contribute to its destruction, increasing the level of dangerous ultraviolet radiation.
- Moral hazard. Governments fear that the availability of a “technological solution” will give large corporations and countries an excuse not to reduce emissions, which will only make the problem worse in the long run.
- Geopolitical conflicts: Because technology affects the entire planet, its unilateral use by one country can lead to accusations of causing natural disasters (droughts or floods) in other regions, threatening international security.
- Ocean acidification. Geoengineering only masks the temperature, but atmospheric carbon levels remain high, so the oceans will continue to absorb carbon and acidify, which destroys marine ecosystems.
- Finally, we don't know for sure all the effects of such actions. Even the most powerful supercomputers are unable to simulate the entire chain of possible consequences. Some suggest that such intervention could lead to a self-sustaining cooling that would freeze the planet.
If the idea is successful
In the future, Stardust Solutions plans to sell its technology to national governments or international organizations such as the United Nations. Potential customers could include not only the United States or China, but also countries that suffer the most from heat, such as Ghana.
Stardust executives see geoengineering as a way to buy time to develop renewable energy and build nuclear reactors without disrupting people's livelihoods. They hope to reach an international agreement similar to the 1987 Montreal Protocol that would regulate atmospheric interference on a global scale.
At the same time, critics warn of the dangers of dependence on such a method. If humanity begins to cool the planet artificially and at the same time slows down the transition to clean energy, stopping the scattering of particles will be almost impossible without catastrophic consequences, writes The Atlantic. The planet may find itself in a situation where it will have to pay a private company for decades or even centuries to maintain a habitable temperature.
Despite all the risks, supporters of the idea believe that in conditions of rapid warming, the presence of such an “insurance policy” is critically important for the survival of future generations.