I remember reading, twenty-five years ago, Kim Stanley Robinson’s Mars trilogy about the colonization of the red planet. The idea that we humans could, over many decades, terraform an inhospitable, deadly atmosphere into something living seemed very cool. Back then I had no idea that our own planet’s atmosphere might become hostile in my lifetime. If the pioneers in the Mars trilogy could use science and technology to make that planet liveable, can’t we do something about ours?
The Oxford Geoengineering Programme defines geoengineering as the deliberate large-scale intervention in the Earth’s natural systems to counteract climate change. Two main areas are focused on to help reduce global temperatures: the reduction of solar radiation and the removal of greenhouse gases from the atmosphere. In case you hadn’t guessed from the title of this article, I’ll be considering the potential costs as well as the benefits of each below. Because guess what, there’s no such thing as a free lunch.
Solar Radiation Management aims to reflect a small proportion of the Sun’s energy back into space. Methods of doing this vary from the simple – such as using brighter colours or more reflective materials on buildings and roads (also called albedo enhancement) – to the more outlandish ideas such as launching massive mirrors into space. While the latter would surely work, its readiness and cost effectiveness must be questionable, especially with a shelf-life potentially limited by bombardment from micro meteors.
A more pernicious method of reducing sunlight involves stratospheric aerosols – scattering particles into the upper atmosphere or into clouds. We know this method definitely works because history is full of case studies: massive volcanic eruptions spew billions of tonnes of particles into the atmosphere and global temperatures subsequently drop for a year or two. Most famously, the eruption of Mount Tambora in 1815 resulted in the ‘year without summer’ in 1816, and helped create two of literature’s greatest horror stories: Dracula and Frankenstein. Volcanic eruptions even inspired the plot in the final part of my Gaia Trilogy but, somehow, I doubt that will ever become a gothic classic!
Researchers have been using computer models to stimulate the effects of stratospheric injection to figure out how much would be needed and, importantly, what side effects could arise. These might include changes in rainfall, reduced crop yields, and damage to the protective effects of the ozone layer. And if the global financial crisis or the pandemic has taught us anything, it’s that computer models are rarely able to predict the full ramifications of complex systems.
So, if reducing sunlight seems like a risky or very costly method of combating climate change, what about carbon dioxide removal? We’re on safer ground here, since the aim is to reverse what’s been done to the atmosphere in recent decades rather than introducing a radical new effect into the climate. Chopping down fewer trees and planting more saplings seems a pretty obvious starting point but has to work with local land management policies and the economics of our own consumerism.
Helping more phytoplankton grow in the oceans – through iron fertilisation – could also reduce carbon dioxide in the atmosphere and be combined with the dispersal of ground-up rocks such as limestone to help combat oceanic acidification. But research is needed into potential side effects on marine life. While we’re at it, we might have to find a way to maintain the North Atlantic drift – the warm currents that stop Northern Europe feeling as cold as Labrador. Melting North Pole ice is changing the salinity of this conveyor belt of water, potentially shutting it down for good.
Carbon capture grabs the offending gas as it tries to leave polluting power stations or factories. This can be frozen and stored deep underground in a technology already in use by the Norwegians and will surely prove popular as countries struggle to reduce carbon emissions directly. Progress is being made with machines that can suck carbon dioxide directly from the atmosphere. However, these methods still require huge amounts of energy and, in some cases, water to work so are not yet feasible on a scale large enough to achieve significant progress.
All geoengineering solutions come with a financial cost. As technological advances reduce those costs and the price of doing nothing rises, I’m sure we’ll see more and more of these methods being used in the years ahead. I just hope we keep an eye on those side effects. One consequence that I haven’t mentioned yet is the potential for induced behavioural changes. If we come up with a viable engineering method for combating climate change, will this lessen consumers’ willingness to make lifestyle choices or politicians’ inclination to pursue potentially unpopular legislation in the name of climate change? I hope not.
Whilst progress is being made in reducing carbon emissions, most projections show us failing to hit Paris Agreement targets. I am a big fan of Sci-FI. I’m an even bigger fan of science. Researched properly, used sensibly, I am sure that we can and should adopt some of these geoengineering solutions to climate change as well as continuing to pursue behaviour changes from individuals, companies and governments. Spoiler alert: Kim Stanley Robinson’s Mars trilogy has a happy ending. I hope our planet’s story does too.

David Barker is the author of the Climate Fiction Gold trilogy (Bloodhound Books) – and gives talks on water shortages and climate change. Prior to writing full time, David worked in the city as an economist where his fascination with commodity shortages began.
He attended the Faber Academy in 2014 and, more recently, completed a scriptwriting course with the National Writing Centre. When not writing thrillers or scripts, David likes to create stories for younger readers and joined the Society of Children’s Book Writers and Illustrators in 2018.
David participates in Radio Berkshire’s monthly book show, plays tennis & golf and does amateur dramatics (when theatres are allowed to be open). He lives in Berkshire with his wife and daughter, who are both much better at acting than him.
You can find out more about David and his writing at: https://davidbarkerauthor.co.uk