Scientists may have found a solution to one of the world’s biggest problems, global warming. According to a new study, spraying diamond dust into the stratosphere could reflect sunlight and lower the Earth’s temperature. Researchers have determined that spraying five million tons of diamond dust into the stratosphere annually could reduce the Earth’s temperature by 1.6 degrees and alleviate the effects of global warming.

According to Science.org, researchers believe that by reflecting sunlight, diamond dust sprayed into the stratosphere could reduce heat based on the cooling effect caused by volcanic smoke and particles covering the atmosphere and causing the Earth to cool in the past. Scientists conducting research to combat global warming have proposed controversial and even fantastical ideas such as throwing iron into the oceans or launching mirrors into space to cool the planet through “geoengineering” methods.

One of these proposals is a solar geoengineering method known as “stratospheric aerosol injection,” which aims to reduce the sun’s impact by spraying aerosols into the stratosphere to create a volcanic winter-like cooling effect. Historic volcanic eruptions have released millions of tons of sulfur dioxide into the stratosphere, leading to sulfate aerosols reacting with water vapor and other gases to reflect sunlight back into space, creating volcanic winters. The eruption of the Pinatubo volcano on the island of Luzon in the Philippines in 1991 led to a 0.5-degree cooling of the Earth for several years.

Researchers were considering spraying sulfate aerosols into the atmosphere following this phenomenon, but it was determined that artificial sulfur injections could lead to subsequent sulfuric acid rains, deplete the ozone layer, and disrupt lower atmospheric and climate patterns. Climatologists and postdoctoral researchers Sandro Vattioni and his team from ETH Zurich University in Switzerland researched other substances that could serve as alternatives to sulfur dioxide.

The team investigated compounds made of calcite, the primary component of limestone, diamonds, and aluminum, which could remain airborne for longer, trap heat without clumping, and reflect radiation for lasting cooling effects. To achieve this, a “3D climate model” was created, considering the chemistry of aerosols, their movement in the atmosphere, and their behavior towards heat.

Experiments were conducted on seven compounds made of sulfur dioxide, along with calcite, diamonds, and aluminum, with each trial taking over a week in real-time on a supercomputer, evaluating the effects of each compound for 45-year periods. The results showed that diamond particles were the best at reflecting radiation and remained airborne without clumping for longer periods.

Diamonds were considered a preferred option due to not engaging in reactions that could create acid rain like sulfur, making them suitable for long-lasting effects. Vattioni stated that for a lasting impact, it would be necessary to spray five million tons of diamond dust into the stratosphere annually, cooling the planet by 1.6 degrees. Vattioni also mentioned that sulfur was the second worst option due to its tendency to absorb light at certain wavelengths, trapping heat, which could disrupt climate patterns by causing effects like El Nino.

On the other hand, some scientists believe that spraying diamond dust into the atmosphere annually until 2100 would cost approximately 200 trillion dollars, making it 2,400 times more expensive than the sulfur dioxide option, leading them to think that the sulfur alternative would be more efficient.