Too hot? Diamond Dust Can Cool the Earth

Over the years, climate scientists have been discussing the feasibility of by using jetting aqueous sulfate to the sky to reflect and scatter sunlight, in order to cool the earth. This earth engineering method imitates the cooling effect of volcanic eruption in essence, but because it is controversial, it has not been tested. And researchers from Harvard University calculate that using diamond or aluminum oxide solid nanoparticles to try this kind of "solar radiation management" which may be more effective, and less damage to the environment than sulphate.

According to the report in the journal Nature, Debra Wessonstan, an atmospheric modeling expert at the University of Harvard, says that they published the latest study in the journal Atmospheric Chemistry and Physics, and by analyzing the physical and chemical reactions of these nanoparticles with different materials in the atmosphere, they have simulated the effect of these particles in details for the first time and made the comparison with the sulfate.

Studies have shown that aluminum oxide and diamond dust have a small effect on the ozone layer obviously. The stratospheric warming that caused is not high and the increase of the earth's surface diffuse light is not so much. In addition, the aluminum oxide dust has similar cooling effect with sulfate spray, while the effect of diamond dust can reach more than 50%.

Of course, the cost of diamond dust will be a lot of money. And hundreds of thousands of tons of diamond dust can offset a few percent of greenhouse gases of man-made emissions every year. According to the current prices, it will cost billions of dollars every year. Although the research team believes that the cost of artificial diamond will decline in the future, they still focus on the aluminum oxide because it is easier to produce, whose chemistry performance can also be studied more thoroughly.

However, scientists warn that aluminum oxide dust and diamond dust both have the unknown risks. Research on volcanic has let people have considerable knowledge about sulfate, but they are not well understood about the chemistry of the solid particles, such as their surface catalytic reaction. The research team from Harvard University is making up the lesson now through laboratory experiments.