Can diamond dust help cool the Earth? Exploring Geoengineering Costs and Risks

Injecting diamond dust into the atmosphere could cool the planet by 1.6ºC, according to a recent study published in Geophysical Analysis Letters. Led by Sandro Vattioni, a climate scientist at ETH Zürich, the research explores whether diamonds, unlike commonly used materials such as sulfur, could offer a safer and more effective method for injecting stratospheric aerosols. This method aims to reflect solar light back into space to mitigate global warming.

Diamonds versus sulfur for cooling

While sulfur has been studied as a cooling agent (largely inspired by volcanic eruptions that inject sulfur dioxide into the atmosphere), the material poses significant risks, including ozone depletion and acid rain. Diamonds, on the other hand, are chemically inert and would not contribute to these dangers. Vattioni and his team ran complex climate models to assess the impact of different materials. Diamonds were noted for their reflective properties and their ability to remain airborne without clumping.

The high costs of diamonds

Although diamonds could offer a promising solution, their cost is a major drawback. With synthetic diamond dust estimated to cost around $500,000 per ton, scaling up production to inject 5 million tons per year would require a huge financial commitment. According to Douglas MacMartin, an engineer at Cornell University, the cost of deploying diamond dust between 2035 and 2100 could reach $175 trillion. This price far exceeds that of relatively inexpensive sulfur, which is readily available and much easier to disperse. MacMartin suggests that sulfur may still be the material of choice due to its lower cost and ease of use.

The debate on geoengineering continues

Geoengineering research, including studying alternative materials such as diamonds, remains a controversial topic. Critics such as Daniel Cziczo, an atmospheric scientist at Purdue University, argue that the risks of unintended consequences outweigh the potential benefits. However, Shuchi Talati, executive director of the Alliance for Fair Deliberation on Photo voltaic Geoengineering, emphasizes that research is essential to understanding all possible options, especially for nations most vulnerable to climate change.