GabyThis idea sounds like it was borrowed from a science fiction blockbuster. But it’s not: its pros and cons are being weighed seriously by real scientists. A team of researchers from the Institute of Atmospheric and Climate Science at the Swiss Federal Institute of Technology Zurich believes that spraying millions of tons of diamonds into the sky could ultimately be the solution to global warming that the world has been searching for. However, there’s one catch: this geoengineering project is incredibly expensive (we’ll get to the exact figure shortly). The team attempted to calculate its cost while studying the impact of spraying various aerosols in the stratosphere on cooling the Earth. They found that diamonds are significantly more effective than other solid substances that scientists modeled. Their model specifically showed that releasing 5 million tons of diamond dust into the stratosphere each year could cool our planet by a staggering 1.6 °C.
What conclusions did the scientists reach? In their new study, the team aimed to determine whether we could cool our planet by dispersing particles that reflect sunlight using a method known as stratospheric aerosol injection (SAI). Most previous research has focused on injecting sulfur dioxide (SO2) into the atmosphere—a process that occurs naturally during volcanic eruptions. However, as the scientists noted in a paper published in Geophysical Research Letters, this approach comes with several limitations. Sulfur dioxide not only causes acid rain worldwide but can also harm the ozone layer and disrupt weather patterns.
To address this, the researchers created a three-dimensional climate model that demonstrated the effects of spraying six solid substances in the stratosphere: diamond, calcite, aluminum, silicon carbide, anatase, and rutile.
This model allowed the scientists to analyze the impact of each particle on climate change. They were particularly interested in how each particle would absorb or reflect heat, how long it would remain in the atmosphere, and whether it would clump together with other particles. The results showed that diamond dust reflects heat the best, stays airborne longer, and does not clump together. Since diamonds are inert, they do not cause acid rain, as reported by the Daily Mail.
“The side effects on circulation and climate, especially from injecting diamonds, could be significantly reduced compared to SO2, making diamond particles the most suitable for SAI in terms of optical properties compared to other materials studied,” the team explained. However, to cool the planet by 1.6 °C—enough to prevent the worst consequences of global warming—a massive amount of diamonds would be required. In an interview with Science, lead author Sandro Vattioni stated that to achieve this effect over 45 years, 5 million tons of diamond particles would need to be sprayed into the stratosphere annually. This project could cost around $200 trillion by the end of the century!
What does this mean? The results are more than enough to reach the sobering conclusion that spraying diamonds into the sky is unlikely to become a reality anytime soon. Nevertheless, this research undoubtedly serves as a springboard for further exploration of the topic. “We propose conducting additional studies on the agglomeration processes in turbulent aircraft trails, as well as measuring the optical properties of various potential solid particle materials,” the team added.
Global greenhouse gas emissions are rising year after year, causing Earth’s temperature to soar. Last month was the second hottest September on record, with the average global air temperature reaching 16.17 °C. Moreover, several months in 2024 have already broken previous records, becoming the hottest on record, including January, February, March, April, May, and June. Climate scientists around the world are feverishly searching for ways to tackle the climate crisis. First and foremost, as is well known, we need to remove greenhouse gases from the air and limit future emissions.
