Just when I thought we’d gotten over the silliness of trying to ameliorate our fossil-fuel misbehavior with geoengineering tactics like seeding the oceans with iron particles (to reduce acidification), along comes another wild idea; sending sulfur dioxide into the stratosphere to deflect the sun’s rays and cool the earth.
Photo: James Jordan, Creative Commons, Flickr
A number of climate change scientists envision geoengineering tactics like the one mentioned above as a way to curb global warming, if other methods, like conservation and emission’ reductions, fail. They say that sulfur dioxide, injected into the stratosphere (beginning about six miles above earth), would cause the sulfur to interact with other substances to form particles that block varying degrees of sunlight, depending largely on how much sulfur dioxide is used.
As Wired.com pointed out recently, there are no laws preventing wannabe mega-fixers from following through with these schemes. The only
Sulfur dioxide, as emitted by coal-burning power plants and volcanoes, is the primary cause of acid rain. Proponents of the above method argue that the sulfur dioxide won’t be in the trophosphere – the earth’s weather zone – but in the stratosphere, which rises from about six to thirty miles above the earth. This, they assure us, means that the sulfur dioxide won’t come down as rain, but remain above the earth longer and be more stable.
This ability to move to, and stabilize in, the stratospheric layer above earth is largely determined by Pacific oscillations, La Nina and El Nino, and to a lesser extent by an atmosphere’s moisture content (more at the equator, less at the poles). Additionally, sulfur dioxide only remains in the stratosphere for a few years. More important, sulfur dioxide undergoes a chemical reaction in the stratosphere, producing chlorine gas, CIO, based on the volume of reactive chlorine in the stratosphere. This chemical reaction increases destruction of the ozone layer.
Sulfur particles have also been shown to move down through the stratosphere collecting other chemicals and dust, and these sulfate-coated dust particles would likely affect cloud formation, precipitation, and the chemistry of the free troposphere, or tropopause. Since the trophosphere is thinner and more vulnerable at the poles, where ozone thinning currently occurs, such a tradeoff, with so many unknowns, doesn’t sound promising.
Simply put, sending sulfur dioxide into the stratosphere is likely to wreak as much havoc within a few years as simply cleaning up our act regarding carbon dioxide and other emissions. The effect of sulfur dioxide on humans is irritation of the mucous membranes, difficulty breathing, and a rise in the incidence of asthma, bronchitis and other lung ailments (with molecular and genetic-level changes still largely unknown).
The ecological effects, on land, are physiological damage to plant cells and tissues, and an increasing acidification that either leaches nutrients from the earth or prevents plants absorbing them. Ergo, no more food. In oceans, acidification destroys the ability of corals and crustaceans to form shells, and these organisms provide the essential habitats and food for the rest of the ocean’s species. Ergo, no more fish. Take away man’s two sources of food – crops and fish – and you can pretty much take away man.
The fact that these ideas continue to crop up, and find favor, indicates that we are quickly becoming – to quote NASA climate scientist James Hansen – "Toast," and everyone in the know knows it, from scientists to government regulators to the heads of multinational corporations. Those who say they don’t – or who argue that global warming is a myth – are the same ones who ignore the water rising around their knees until it’s too late to evacuate.
Unfortunately, when it comes to an uninhabitably warm earth, there is no place to evacuate to.