As the threat of climate change looms larger, will we eventually have to resort to more extreme measures to stop it? Geoengineering is one such measure that’s under consideration. It’s also sparking quite a bit of debate.
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Geoengineering is the act of deliberately intervening in the Earth’s natural systems on a large scale. It’s often discussed in the context of reversing human-caused climate change. Most geoengineering falls into one of two categories:
- Capturing and sequestering carbon
- Blocking sunlight to cool the planet
Some examples of projects that would capture carbon include:
- Fertilizing the ocean with iron to promote the growth of algae, which will absorb excess carbon dioxide
- Pumping nutrient-rich deep ocean waters toward the surface to promote algae growth, a practice called artificial upwelling
- Increasing the amount of crops we grow for bioenergy, burning them for fuel, then capturing the carbon emissions and storing them long-term
- Creating structures with materials that absorb carbon dioxide directly from the air
Examples of projects that involve blocking sunlight include:
- Launching sulfate aerosols into the atmosphere, where they remain suspended and reflect sunlight, cooling the planet — a process that mimics the effect of volcanic eruptions
- Placing mirrors in outer space to reflect sunlight
- Spraying seawater into clouds to increase their reflectivity
As of now, no large-scale geoengineering projects have been deployed, although some small-scale research projects are underway. As research continues, it seems that various geoengineering techniques may be technologically feasible, but their long-term effects are still uncertain.
Arguments for Geoengineering
Very few people advocate the use of geoengineering now. Some researchers and environmentalists, however, say that it could become necessary as a last-ditch effort if climate change continues to worsen. The vast majority of researchers, however, say that it should be used as a supplement to reducing the amount of greenhouse gases we release into the atmosphere rather than a replacement. Renewable energy initiatives and other such projects would still be relevant in a world in which we use geoengineering.
While few people promote using geoengineering now, more advocate conducting research into the matter. These advocates say that we need more research to help determine whether geoengineering is feasible and whether it’s safe.
Some opponents of geoengineering feel that humans shouldn’t change natural systems on a large scale. One counter-argument is that people have been altering natural systems for years without realizing it. Although it had negative impacts in the form of climate change, geoengineering could enable us to reverse the effects we’ve already had on the environment.
Scientists are beginning to research whether geoengineering is safe. A recent analysis published in the journal Nature Climate Change concluded that using solar geoengineering to reverse about half of global warming wouldn’t worsen tropical cyclones, extreme temperatures and extreme rain or reduce water availability. Less than half a percent of all the places, the paper found, would experience exacerbated climate change effects as a result of solar geoengineering. More research on the subject, however, needs to be done before we can draw any real conclusions.
Arguments Against Geoengineering
There’s still a lot we don’t know about how geoengineering projects would impact the environment. The natural systems they would affect are incredibly complicated, so it would be difficult to predict all the side effects they may have. This unknown factor is why many opponents of geoengineering say it’s too risky.
Some research has found that many geoengineering techniques could have harmful side effects. Researchers from the Helmholtz Centre for Ocean Research in Kiel, Germany recently modeled five geoengineering techniques and concluded that their side effects could be “disastrous.” The scientists wrote in Nature Communications that reflecting sunlight into space could change rainfall patterns and that adding iron to the ocean would impact oxygen levels in the water.
The Kiel researchers also wrote that two of the five methods they studied could not be safely stopped. Stopping ocean upwelling, they wrote, could cause a rapid rise in global temperature. Stopping geoengineering may cause temperatures to rise too quickly for species to adapt, impacting biodiversity.
Some have even opposed geoengineering altogether. Opponents of geoengineering say that it would take attention and resources away from research into reducing our greenhouse gas emissions and adapting to the impacts of climate change. Others believe that if people perceive that geoengineering is an option, they’ll stop caring about reducing emissions and otherwise protecting the environment, a phenomenon known as the bystander effect.
Other challenges are the societal, ethical and political aspects of geoengineering. These environment-altering technologies could impact the entire planet’s population. Does any one group have the right to take such a huge risk that could affect so many people? Of course, we have been altering the environment for many years, but doing it on purpose presents new questions.
The Need for More Research
We still don’t really know what the impacts of geoengineering would be. The studies that have been done have found conflicting results, so we need more research to get a better understanding of the issue. There’s been a lot of discussion about how to responsibly conduct geoengineering research. The world will likely continue to debate the topic before anyone takes any significant steps related to it.
We’re slowly reducing our greenhouse gas emissions and will likely continue to do so into the future. According to data from Bloomberg New Energy, by 2040, power generation from renewables will have increased by nearly 170 percent, and generation from coal will have decreased by more than 50 percent. While we’re making progress, we still need to make a lot of significant changes to slow the global temperature rise.
Maybe one day, geoengineering will be necessary. On the other hand, perhaps research will reveal that its risks don’t outweigh its benefits. There’s still a lot we don’t know about the topic, but with climate change posing such a significant threat, we may need to explore the idea further.