Geoengineering Not the Solution to Climate Change
Geoengineering, or the large-scale manipulation of the Earth's climate, is not the solution to climate change, according to new research. Unfortunately, there is no quick fix to the global climate problem, and curbing carbon emissions is really our best bet to combat its effects.
Researchers with the US National Academy of Sciences say in their new two-volume report that while in theory geoengineering may seem like a good idea, it's actually both "irrational and irresponsible."
"Climate intervention is no substitute for reductions in carbon dioxide emissions and adaptation efforts aimed at reducing the negative consequences of climate change," the researchers wrote. "However, as our planet enters a period of changing climate never before experienced in recorded human history, interest is growing in the potential for deliberate intervention in the climate system to counter climate change."
Two popular examples of geoengineering that are gaining attention are carbon dioxide removal (CDR) and albedo modification, which involves making Earth more reflective to the Sun's rays so warming is diminished. For example, scientists might send mirrors into space or put sulfur dioxide in the stratosphere.
CDR seems pretty self-explanatory, tackling the root of the problem - that is, removing large concentrations of greenhouse gas in the atmosphere and locking it away underground or in the oceans. And while CDR has the advantage of being a less risky option, it's also very costly and a long way off from making the kind of impact we need.
On the other hand, albedo-modification techniques could be applied now and at less cost, however, its effects would only be only temporary and have serious unknown consequences. What's more, other impacts of carbon emissions like ocean acidification would continue anyway, and if the technique were ever discontinued, rapidly rising temperatures could cause cataclysmic events.
"That scientists are even considering technological interventions should be a wake-up call that we need to do more now to reduce emissions, which is the most effective, least risky way to combat climate change," committee chair Marcia McNutt, said in a news release. "But the longer we wait, the more likely it will become that we will need to deploy some forms of carbon dioxide removal to avoid the worst impacts of climate change."
Carbon Dioxide Removal
Despite the researchers' warnings of geoengineering, some methods are being studied for possible future use. For example, ending deforestation (a goal for the year 2030) and restoring forests is an option. Tropical forests in particular are more effective at fighting carbon dioxide (CO2) than previously thought.
In general, just through the natural process of photosynthesis, forests and other land vegetation currently remove up to 30 percent of human CO2 emissions from the atmosphere. Tropical forests are to thank for the bulk of this work, absorbing a whopping 1.4 billion metric tons of CO2 out of the total global absorption (2.5 billion metric tons).
"This is good news, because uptake in boreal forests is already slowing [with climate change], while tropical forests may continue to take up carbon for many years," lead researcher David Schimel of NASA's Jet Propulsion Laboratory, who was behind that study, said in a statement.
According to a related study, some forests may be more efficient at absorbing carbon than others due to a variety of factors, such as the nutrition of the soil. Meaning, nutrient-rich ecosystems can retain more carbon while those in nutrient-poor soils pend less time taking up carbon, and more time searching for available nutrients. (Scroll to read on...)
But we don't have to rely on Mother Nature to take up the world's excess carbon. Scientists are also developing carbon capture methods in the lab. Researchers have tried everything from carbon-trapping "sponges" and baking soda to even converting it into a less harmful organic compound, known as oxalate.
However, more research is needed on these CDR methods, and like the new report says, these approaches are years away from being implemented on a large enough scale.
Meanwhile albedo modification (AM) is a more outlandish technique to fighting the effects of climate change.
"The USA National Academy report makes a smart distinction between slowly and deliberately putting carbon back underground, and tinkering with sunlight reflection and adjusting the atmosphere," Stuart Haszeldine, a professor of carbon capture and storage at the University of Edinburgh, said in a statement. "The first is slower, do-able, visible, and controllable but will cost more. The second is cheaper in the short term, but is poorly understood, will create global regions who are losers, and also means that humans have to keep maintaining the Earth's annual atmospheric injection." (Scroll to read on...)
These technologies could, mind you, reduce average global temperatures within a matter of just a few years. Releasing sulfur dioxide, a type of aerosol, into the air for one would be effective - similar to the effects of large volcanic eruptions, which have been shown to help slow down global warming.
But because AM is so cheap and easy, any nation could decide at any moment to send sulfur into the atmosphere - a recipe for disaster.
"There are issues to do with the perceptions of the technology that make doing the stratospheric aerosol injection something that would be politically very dangerous to do without an international agreement... If you were to do it, any negative event that occurred would be attributed by some party or another to that intervention," Professor Steve Rayner from Oxford University told The Guardian.
Aside from the theoretical politic problems, in the end spraying aerosols into the atmosphere does nothing to help the original problem - the accumulation of greenhouse gases that are warming the planet. These levels hit a record high in 2013, and without intervention show no signs of stopping.
But according to the US National Academy of Sciences research team, this does not mean climate intervention in the form of geoengineering like CDR and AM.
"These reports should guide federal agencies in supporting research on climate-intervention technologies, while keeping separate any decision-making about their implementation," noted National Academy of Sciences President Ralph J. Cicerone.
Rather, the point of their report is that reducing greenhouse gases is the only, and best solution to saving our planet from warming.
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