As our planet warms, climate anxiety rises with the mercury and solutions that might have seemed extreme in the past suddenly see positive light in the media. That’s how geoengineering has become a media darling, seeing positive press in Wired and The Atlantic. But resorting to geoengineering will not constitute a cure for our ecological problems. At best, it’ll be a bandage on a gaping wound: fine in an emergency, but no long-term substitute for a complete fix.
A Brief History of Geoengineering
From its beginnings as a radical idea in the Lyndon Johnson White House, “climate geoengineering” has achieved buzzword status. Today, there are many proposed methods of lowering the Earth’s temperature by deliberately manipulating large-scale environmental processes. The most popular, however, is still one of the oldest. To understand it, you must first understand albedo.
Albedo is the measure of the reflectiveness of the Earth. The Earth needs to reflect a certain amount of light to maintain its temperature. Think of an asphalt driveway that absorbs almost all of the light that hits it. That light becomes heat, which makes the driveway too hot to touch and raises the ambient temperature. This is why cities with little greenery become heat islands.
The asphalt absorbs light because it’s dark grey and dark colors absorb light. On the other hand, the polar ice caps reflect almost all of the light that hits them. Without these high-albedo areas, the Earth would become several degrees hotter. As the polar ice caps melt, the Earth’s overall albedo falls, causing the planet to warm even more.
The most commonly discussed strategy for increasing the Earth’s albedo is by blasting reflective particulates into the atmosphere. Some scientists propose that sulfur compounds, mimicking the makeup of volcanic gases, could work for this purpose, although they could also erode the ozone layer and cause acid rain. Relatively speaking, blasting chemicals into the upper atmosphere would be inexpensive, although it would need to be maintained and collateral costs could eventually mount.
Other ways to increase the reflectivity of the planet include orbital mirrors and coating low-albedo areas of the planet in white or light-colored substances. The city of Los Angeles is already accomplishing this in a small way by painting some streets white.
Other Kinds of Geoengineering
Albedo enhancement is just one of several strategies in consideration for remediating global climate change. When news articles and governments approach the concept of geoengineering, this is most often the strategy upon which they focus. It’s direct, easy to understand, and addresses what seems to be the most significant problem with our environment currently.
Ocean Alkalinity Enhancement
However, the other proposed geoengineering methods bear consideration too. Albedo enhancement won’t solve the problem of ocean acidification, for example. When carbon dioxide interacts with water, it generates carbonic acid. This isn’t a serious problem under normal conditions, but when there’s too much carbon dioxide in the atmosphere, carbonic acid can accumulate and change the overall acidity of the ocean.
The ocean is naturally slightly basic. When that changes, the water can dissolve the calcium-based shells of mollusks, bleach and kill coral, and generally wreak havoc on an ecosystem not prepared to handle such a catastrophic event. Researchers have proposed adding massive amounts of limestone, silicates, and other dissolvable bases to the sea to return it to a healthy pH level.
Biochar involves burning organic matter, which is already full of carbon, and then burying the resulting charcoal. If done correctly, this process would sequester carbon underground. A variation on this theme has energy companies using the process to generate electricity, capturing the resulting smoke, and sequestering that, too.
Also called afforestation, this is the process of replanting trees en masse. Because trees are carbon-based life forms that use carbon dioxide as fuel, and because they are large, they have the potential to store a lot of carbon that’s currently in the atmosphere. Planting billions of trees would be a safe, natural way to lower carbon levels.
Phytoplankton are microscopic plants that float near or on the surface of the ocean. Like trees, algae, and other plants, they inhale carbon dioxide. Spurring their growth can cause them to sequester carbon from the atmosphere at a higher-than-normal rate. However, natural resource scarcity generally keeps their growth in check.
Ocean fertilization would involve dumping a large amount of iron, the scarcity of which often limits phytoplankton growth, into an area of the sea. This would goose the plankton’s growth and the plankton would pull carbon from the air. However, it’s unclear how this practice would affect marine fisheries.
Certain rocks, particularly silicates like olivine, react well with carbon dioxide. The idea behind enhanced weathering is to crush these minerals and spread them over large areas, eventually allowing rain to wash them into the water. There, they would contribute to the formation of calcium carbonate, a common, stable mineral found in bodies of water.
The Cons of Geoengineering
Aside from the health and ecological side effects of introducing sulfur into the atmosphere, the problems with geoengineering have mostly to do with human behavior. In an ideal world, geoengineering would be carried out responsibly and with oversight. Biochar would be promptly buried, the smoke from burned trash would be captured and contained, and the planet would collectively move toward a clean, safe energy economy and an agricultural system that works with Nature instead of against it.
However, our collective track record on moderation is not good. The fact that our governments, commercial structures, and individual habits have driven us to measures as extreme as sulfur injection is a testament to our collective inability to moderate ourselves. If we take the trouble to mitigate global warming using technology, then it is possible that companies, governments, and entire societies will take those actions as license to continue burning gasoline for fuel so long as it’s available. Imagine the marketing: climate change is solved, no need to worry, buy a new gas-guzzler.
The quick fix of geoengineering also belies the extent of the problem that we face. It is not just the carbon in the atmosphere that threatens our way of life, but the way humans treat the entire natural system. From mining out and then throwing away resources to indiscriminately killing pollinators along with pest insects, our way of life also requires serious changes. This will be harder than spending a few billion to blast sulfur into the sky.
In order to use geoengineering safely, our species must first own up to its limitations. We are neither as smart nor as good as we think we are. We’ve already altered nature to suit our purposes, and the result has been catastrophic. Now we propose to alter it again to save ourselves, and while it may become necessary to do so, the outcome is a question mark. Nobody has ever dumped billions of tons of limestone into the oceans before. Nobody has ever artificially fertilized the sea to turn it into a carbon sink. Nobody has ever weighed the net benefit of having a healthy ozone layer against a fatal rise in the planet’s temperature.
The Positives of Geoengineering
There are geoengineering measures that are low-risk. Afforestation is an obvious and easy strategy that can (and should) be adopted at the local level. While tree-planting alone can’t solve our problem, it could make a huge dent, especially in combination with a carbon tax and infrastructure improvements for electric cars and public transportation. Better yet, it generates stable, valuable jobs for botanists, gardeners, and foresters. Planting trees is literally a job creator.
Taking geoengineering seriously could force governments to generate a collective climate change plan of action. In the case of extreme geoengineering, as with albedo enhancement, a government’s incentive to end the process might be significant. Aside from ozone and acid rain issues, extra aerosols won’t be good for people with asthma, COPD, and other breathing problems. Reducing sunlight may impede crop growth and solar panel efficiency. Because it’s never been tried, it’s difficult to know. Likewise, predicting how extra limestone will impact the ocean’s ecological balance, especially when it comes to commercially viable fish, is impossible. Life under extreme geoengineering could become quite miserable for the average voter. While this is a bad reason to finally fix climate change, it could also serve as a lesson. Maybe this is how our species will finally learn that an ounce of prevention is worth a pound of cure.
Finally, as the Arctic melts and the Earth warms, there may be no way to avoid taking drastic measures. If there is one thing that can be said for sulfur aerosols, it’s that they may allow life on Earth to continue if we are truly in a corner. That’s time that we can buy to set things right. If geoengineering can give us a reprieve, then let’s not waste it.