Sulphur sunshade is a stupid pollution solution



It's a credo of consumer capitalism: never address the cause when you can create an industry treating the symptoms.

'Problem' pollution is overrun by 'solution' pollution. Cartoon by Greg FoysterThis is the logic behind many profitable businesses, from cholesterol-lowering pills that compensate for poor diet and lack of exercise to factories that recycle unnecessary packaging.

Now there's a new technofix on the table, and it's called geoengineering. Geoengineering means intervening in the Earth's climate to counter, or offset, global warming. It's hacking the planet on a monumental scale.

Some proposals sound like pure science fiction. Building 'artificial trees' to suck in carbon dioxide. Fertilising entire oceans with iron, trigging carbon-sequestering algal blooms. Launching a fleet of ships to patrol the ocean, pumping seawater into the air to 'brighten' marine clouds.

The most ambitious and widely studied is spraying sulphate particles into the upper atmosphere to reflect sunlight, cooling the planet.

The idea comes from huge volcanic eruptions, which can blast millions of tonnes of sulphur into the stratosphere, creating a kind of chemical sunshade. When Mount Pinatubo in the Philippines erupted in 1991, the Earth cooled by about half a degrees Celsius over the next year.

After decades of being taboo, this outlandish scheme, called 'solar radiation management', is now being taken seriously. It's been explored through scientific papers in major journals, reports of the UK's Royal Society, hearings in the US Congress, and a recent report of the US National Academy of Sciences.

Some environmentalists and climate scientists say it may be a 'necessary evil' to avoid catastrophic climate tipping points. Controversially, the most recent IPCC Assessment Report mentioned geoengineering in the prominent final paragraph of its Summary for Policymakers.


"Dimming the sun wouldn't solve the other problems caused by carbon pollution. Dissolved carbon dioxide would still acidify our oceans. The climate would still change."


There are deep pockets behind it too. Techno-philanthropist Bill Gates is a leading financer. Venture capitalists are circling, and some proposals have already been patented.

A firm called Intellectual Ventures owns the intellectual property for the 'StratoShield', an invention to deliver sulphur dioxide into the upper atmosphere through a 30-km-long hose supported by balloons. A professor at Harvard, David Keith, is pushing for more research and testing.

Neoconservative think tanks have leapt at the technology, arguing it's a cheaper solution to global warming than cutting emissions and restructuring the economy. Once the post-Paris Agreement buzz wears off and governments realise the hard work ahead of them, they might find this line seductive.

As a thought experiment to highlight the warped logic behind geoengineering, I'm proposing my own climate-hacking invention. It's called The Problem-Solution Generator, and it has two parts.

The 'Problem' is a dirty coal power station that spews carbon dioxide into the lower atmosphere, overheating the planet. Burning coal also releases other forms of air pollution — sulphur dioxide, nitrogen oxides, soot particles and mercury — responsible for millions of deaths worldwide.

The 'Solution' is a 30-km-high smoke stack which separates the sulphur dioxide emissions and pumps them into the stratosphere, where they won't make people sick and should cool the planet. Thus a single machine generates a problem and then solves it — The Problem-Solution Generator!

Of course, we could shut down coal power stations and not create the problem in the first place. But that would address the cause — rising carbon emissions — which isn't what technofixes like geoengineering are about. So let's continue the thought experiment, using some of the same arguments as for other sulphur-spraying ideas.

Advocates of solar radiation management say that, unlike other responses to global warming, it doesn't upset the economic or political status quo. It's as if the current composition of society is more permanent and fixed than the composition of the entire upper atmosphere.

The Problem-Solution Generator shares this assumption. Fossil fuel companies could continue making money off heating the planet, while also making money off cooling the planet. It's a win-win!

There are a few concerns. Previous large volcanic eruptions have been associated with lower global rainfall and famine. Climate modelling indicates solar radiation management might dry the Amazon and disrupt the Asian and African monsoons. The sulphur particles could damage the ozone layer.

The biggest fear is switching the off button. Carbon dioxide persists in the atmosphere for centuries, but sulphur particles only stick around the stratosphere for a few years, so if we suddenly stop pumping the stuff up there, the temperature could spike abruptly. The faster the rate of warming, the less time plants and animals have to adapt, risking widespread ecosystem collapse.

But in the spirit of Silicon Valley techno-optimism, let's look at these as opportunities. Lower global rainfall? That's an opportunity for a spin-off industry in cloud-seeding drones. Disrupted monsoons? They'll mostly affect poor African and Asian subsistence farmers, so the cost to the global economy will be small. Dangerous to stop once we start? That just shows what a great business model it is!

Dimming the sun wouldn't solve the other problems caused by increased carbon pollution. Dissolved carbon dioxide would still acidify our oceans. The climate would still change, just differently. We might still see mass extinctions and so forth. But our clever minds will soon solve these problems too. The important thing is that we maintain our faith in human progress.

Sound crazy? This kind of thinking is actually conventional. The underlying assumption of Western industrial society is that nature is a resource for our exclusive use. Geoengineering just takes this domination of the natural world to its logical extreme. In one sense, complete control of the planet is where our civilisation has been heading for centuries.

In Earthmasters, Clive Hamilton writes that geoengineering proposals 'entail building a vast industrial infrastructure in order to counter the damage done by another vast industrial infrastructure'. If the Problem-Solution Generator seems colossally stupid, it's only because it makes the stupidity of geoengineering technofixes utterly transparent.


Greg Foyster headshotGreg Foyster is an environment journalist, an alumni of Centre for Sustainability Leadership, and the author of the book Changing Gears.

Cartoon by Greg Foyster

Topic tags: Greg Foyster, climate change, renewable energy, global warming, carbon tax, geo-engineering



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Existing comments

Back to the bad old days of children with rickets from diminished sunlight.Stupid idea.
marlene bracks | 14 April 2016

Greg, you're not thinking large scale enough! Make the tube 100 kms high and the pollution will drift into space. Just anchor it to a geostationary satellite and all will be sweet. And what a potential for industry. There's bound to be a motza in it for someone. And it will make the earth so beautiful. Can't you just see it: Planet Earth like a spikey ball where every coal fired power station has a 100 km long exhaust stack sticking into space. That's brilliant, yes?
ErikH | 14 April 2016

This is classic Luditism pretending to be sophisticated and cool. So many of your assumptions Greg are just wrong. Coal is a minor part of our global problems and indeed clean Australian coal is a part of the answer and not the problem, as you would have us believe. Road traffic and diesel in particular is a huge issue and new electric engine and battery technology will make a really big difference to global pollution, but we will need much more electricity; as indeed we urgently need now for 2 billion very poor people who don`y have it yet! That is truly unbelievable, not the technologies that will sort out the problems even if they may create some new lesser ones.Wind/solar are very expensive and just will never do the job. Clean coal, nuclear in some form (perhaps Thorium) and new technologies still being imagined will do the trick. Fortunately we as a species are highly resilient and clever.
Eugene | 14 April 2016

I find it hard to believe Eugene's remarks are for real. Clean Coal is an Oxymoron. Carbon capture and storage is still a generation away as is any major infrastructure project, including seeding the atmosphere. Delivering energy electrically to my car is less polluting than by petrol tanker. Anyway, it can be avoided with solar panels. I installed solar panels, LED lighting and, needing a new car, purchased a plug-in hybrid. The result was no increase in electricity costs, a saving of $1700 in annual petrol costs and a displacement of 4 Gigawatt-hours of energy generation from the grid.
Peter Horan | 14 April 2016

FYI Greg Foyster, CO2 is a colourless gas. I suspect that the filthy black stuff belching out of the stack in your cartoon is a lot of unburned carbon, commonly known as soot. That was a problem some time ago but not with modern coal-fired power plants.
Gerald Lanigan | 14 April 2016

In reply to myself, that last sentence should read "a displacement of 4 Megawatt-hours of energy generation from the grid."
Peter Horan | 14 April 2016

Hi Gerald, yes, I know CO2 is invisible, but that makes it very hard to depict! I chose to depict the CO2 as black and the sulphur as white for metaphorical reasons: the black represents the problem, the white the solution (or 'whitewashing' the problem). Artistic licence, I guess. Eugene, where to begin! What I've written doesn't make me a Luddite. It's not anti-technology, just questioning a particular unproven, highly risky technology. Most people who know about these issues understand that it's not about depriving the majority world of energy, it's about helping them leapfrog dirty fuels (which create massive pollution problems and climate change) to clean energy, in the same way they've gone straight to mobile phones without the clunky copper wire network first. I'd be open to other forms of energy, including clean coal, if it could be proven that they work and were safe. That's not the case yet, and CCS is unlikely to be proven commercially viable at scale for decades - even the coal industry admits that. We also need to look at the demand side, not just supply. That means energy efficiency measures but also social and cultural change to reduce electricity demand and decouple economic growth from resource use (if possible...more on that another time!).
Greg Foyster | 15 April 2016

Anything to avoid a simpler lifestyle!
Lenore Crocker | 17 April 2016

I can't believe, as a biology student that a environmental journalist wrote this. It makes me sad to see that one accepts the death of his own kind along with million of other species in exchange of the continuation of status quo, of a government that doesn't care about the people. It's sad to see where we humans ended up because our own creations.
Júlio | 19 April 2016

Thank goodness for the likes of Clive Hamilton. Is there scope in our common humanity to change from global domination, which is expressed as destruction, to co-existence and sharing, while we fix the problems?
Max | 23 April 2016


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