Science fiction or fact?
Space reflectors, stratospheric aerosols and biochar … No – these aren’t subjects from the next Star Wars, but possible answers to global warming
Although I am somewhat embarrassed to admit it (as my fiancé loves to mock me), I really do enjoy a good sci-fi movie every now and again (luckily a guilty pleasure shared by many).
However, scenes from this genre (such as space reflectors and interplanetary travel) might become a scientific necessity if we don’t drastically alter the effect we are having on the environment … The full wrath of climate change could be devastating, or it could just result in a need for stronger sunblock – but I’d prefer not to find out.
Enter geoengineering, a possible climate quick fix that requires minimal behavioural changes from humanity – which sounds like something you’d find in a science fiction novel. It is defined as the deliberate large-scale manipulation of the planetary environment to counteract climate change caused by humans.
The technological prospects for geoengineering are vast, but it falls into two main camps: First up is solar radiation management (SRM), a tactic that aims to reflect solar radiation back into space so that it isn’t absorbed by the atmosphere.
Here, the intention is to counteract heat-trapping gases by scattering or deflecting some percentage of incoming solar radiation by, for instance, streaming sulphate particles (or stratospheric aerosols) into the stratosphere (which reflect some sunlight before it reaches the Earth’s surface) or launching sunshades into space.
The other geoengineering strategy is known as carbon dioxide removal (CDR), an approach that involves drawing large amounts of carbon out of the atmosphere and storing it where it won’t cause future harm.
Ideas include the use of carbon dioxide “scrubbers” that would pull large amounts of CO2 straight from the air (or growing forms of biomass) and then reduce it to charcoal (known as biochar) which can be buried.
However, as Simon Nicholson – assistant professor in the School of International Service at American University – explains, SRM strategies are receiving the bulk of the attention.
Nicholson is also the author of The Promises and Perils of Geoengineering, a chapter in the Worldwatch Institute’s latest paper State of the World 2013: Is Sustainability Still Possible?
“It is hard to see a CDR scheme coming online quickly enough, or being deployed at a large enough scale, to make a real dent in the atmospheric carbon load,” Nicholson adds.
He warns, however, that SRM is not any kind of real answer to climate change. “At best, SRM can reduce the planet’s fever for a period,” he says. “Talk surrounding geoengineering is gaining traction because it has the appearance of an easy, sacrifice-free approach to tackling climate change. It is critically important to recognise that there are sacrifices, some obvious and some harder to spot, associated with the bulk of geoengineering schemes.”
One of the most obvious concerns is that geoengineering can potentially cause catastrophic and irreparable damage to the climate as, even with computer models and endless calculations, there are still potential unforeseen problems that may occur with any such large-scale plan (due to our still limited understanding of the world’s climate system).
“The need is for a ‘middle ground’ approach,” Nicholson cautions. “Not geoengineering as a techno-fix but rather geoengineering as one small part of an effort to steer the world to a state of rightness and fitness in ecological and social terms.”
And I completely agree, because (as we have seen in so many sci-fi movies) it isn’t wise to mess with Mother Nature too much.
However, humanity has already done some serious damage – so we need to rectify things in a responsible manner … If not, we might all have to go and live on Mars someday …