This sounds like a science-fiction blockbuster. But it’s not: real scientists are seriously weighing the idea’s pros and cons.
A team of researchers from the Institute of Atmospheric and Climate Sciences at the Swiss Federal Institute of Technology Zurich believes that spraying millions of tons of diamond dust into the sky could become the solution to global warming the world has been searching for.
But there’s a catch: the project would be extremely expensive (more on the price shortly). The team estimated the cost while studying how spraying various aerosols into the stratosphere would cool the Earth. Diamonds turned out to be far more effective for this purpose than the other solid particles the scientists modeled.
The researchers’ model, in particular, showed that the release of 5 million tons of diamond dust into the stratosphere each year could cool our planet by a striking 1.6 °C.
What conclusions have the scientists reached?
In their new study, the team aimed to determine whether we can cool the planet by dispersing sunlight-reflecting particles into the air using a method called stratospheric aerosol injection (SAI).
Most previous studies have focused on injecting sulfur dioxide (SO2) into the atmosphere – a process that happens naturally during volcanic eruptions.
However, as scientists noted in an article published in Geophysical Research Letters, that approach has several limitations. Sulfur dioxide not only causes acid rain around the world, it can also harm the ozone layer and disrupt weather patterns.
Researchers created a three-dimensional climate model that simulated dispersion in the stratosphere for six solid substances: diamond, calcite, aluminum, silicon carbide, anatase, and rutile.
Thanks to this model, scientists were able to analyze the impact of each particle on climate change. The team was 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 best while remaining airborne and does not clump together. And since diamonds are inert, they would not cause acid rain, the Daily Mail reported.
“The side effects on circulation and climate, especially from diamond injection, can be significantly reduced compared to SO2, making diamond particles the most suitable for SAI in terms of optical properties among the materials we studied,” the team explained. However, to cool the planet by 1.6 °C – enough to prevent the worst consequences of global warming – would require a massive amount of diamond.
In an interview with Science magazine, lead researcher Sandro Vattioni explained that to achieve that effect over 45 years, it would be necessary to spray 5 million tons of diamond particles into the stratosphere each year. The team estimated the cost at about $200 trillion by the end of the century.
What does this mean?
The results are enough to reach a disappointing conclusion: dispersing diamonds in the sky is unlikely to become a reality anytime soon. However, the research serves as a catalyst for further study on the topic.
“We propose to conduct additional research on the processes of agglomeration in turbulent aircraft wakes, as well as measurements of the optical properties of various potential solid particle materials,” the team added.
Global greenhouse gas emissions are rising year after year, which is why Earth’s temperature is increasing. Last month was the second-hottest September on record: the average global air temperature reached 16.17 °C.
Moreover, several months in 2024 broke previous records, becoming the hottest in recorded history. This includes January, February, March, April, May, and June.
Climatologists around the world are urgently searching for ways to address the climate crisis. First and foremost, society needs to remove greenhouse gases from the air and limit future emissions.
