The biggest source of climate change, as it is now understood, is carbon dioxide in the atmosphere. This gas traps in heat that radiates from the earth’s surface after sunlight heats it up. By preventing heat from escaping into space, the carbon dioxide causes the average temperatures to increase.
In lay terms, the total thermal heat energy on the earth, H, increases as the amount of incident sunlight that hits the earth goes up but also increases as the amount of sunlight that escapes the earth’s atmosphere goes down.
The more carbon dioxide there is in the atmosphere, the less heat energy escapes back into space. As emissions and the carbon dioxide they bring go up, therefore, more heat is retained and the temperatures go up. Most climate work focuses on this part of the equation, working to reduce emissions of carbon dioxide.
But consider the other side of the solution. What if it were possible to lower the amount of sunlight that reaches the earth’s surface and gets transformed into heat energy in the first place? The New York Times takes a critical look at this alternative solution strategy.
And this second way of reducing the greenhouse effect is gaining traction among scientists, especially since the political side of climate change has so far fallen short of its goal of reducing emissions.
How do you think you could reduce the amount of sunlight that hits the earth? A hint comes from massive volcanic explosions that have occurred throughout history. These eruptions spewed clouds of dust and other particles high into the sky, acting like a big pair of shades for the earth’s surface.
What if we could float tiny particles of, say, sulfuric acid in the stratosphere? Would it have the same effect? Scientists aren’t sure, but many think it could be worth a try.
Alternatively, some scientists in the relatively young field of geoengineering say we could try spraying the oceans and causing the formation of more clouds, also blocking sunlight from reaching the surface.
The Guardian says the science of geoengineering “aims to tackle climate change by”:
- removing carbon dioxide from the air, or
- limiting the sunlight reaching the planet
Critics of these approaches, even acquiescing to the side effects of spraying aerosols of sulfuric acid in the stratosphere, say geoengineering only masks the problem and doesn’t really solve it. But temperatures could still go down.
Geoengineering also has a beat on reducing the carbon dioxide levels in the atmosphere. It turns out, tiny rocks made out of the green-tinted mineral olivine can be used to remove carbon dioxide from the air, just like plants do. Scientists have envisioned green beaches all along the ocean with olivine-containing sand.
Olivine critics say the process would work too slowly to have any positive effect on the environment. Olaf Schuiling, a retired geochemist in the Netherlands, however, says there’s nothing wrong with starting small. “When I started, I was a nutty professor,” the Times quoted him as saying. Nowadays, when he gives a talk about olivine, “the first question after I finish is, ‘Why don’t we do it?'”
How effective would the use of olivine on our nation’s beaches be at reducing the effects of climate change? See Next Generation Science standard HS-ESS3-4 for more information.
