New report concludes polar geoengineering is dangerous

Thus far in my 53 orbits around the sun I have managed to electrocute myself twice. The first was 43 years ago when I was dismantling a hair dryer. I had convinced my parents I needed it because I was building a model hovercraft. What I didn’t tell them was that I would take it apart while it was plugged into the UK mains. This was back before any circuit breakers would sit between me and 230 volts AC. All I can remember is that on touching what must have been the internal switch there was a sharp pain accompanied by a feeling that I can only describe as all the cells in my hand and arm being violently reorganised. I ended up falling backwards onto my bed and staring at the ceiling to contemplate some of my life’s choices.

The second time I’m embarrassed to admit was five years later. I was a 15 year old who thought the solution to a piece of toast stuck in a toaster was to get a metal knife from the cutlery drawer and try and fish it out. No, I did not turn off the toaster. There was a loud band and some sparks. Once the smoke cleared and I got back off the floor I discovered that along with a piece of burnt toast there was now a knife stuck in the toaster as it had become welded to the heating element. 

I was often doing stupid, reckless things. This got me banned from most chemists in my local area who had realised that my repeated purchases of certain substances were not for preserving food but as the ingredient for explosives, rocket propellants and smoke bombs. The small cannon I built was particularly misguided because it was inevitable it would catastrophically fail and eject a cloud of shrapnel across the garden. 

I mention these incidents because they are good examples of behaviour that if anyone else was watching would lead them to yell “What the hell are you doing?!” I would like to humbly suggest that I can see echoes of my youthful curiosity-driven stupidity in many of today’s ideas for geoengineering. Disco balls in space, dumping iron filings into the ocean, deleting clouds; there are multiple proposals to deliberately interfere in the Earth system in order to try to offset the rise of global temperatures being produced by our greenhouse gas emissions and land use change.

Every now and then there is a report that evaluates geoengineering. The 2009 Royal Society Geoengineering the climate: Science, governance and uncertainty is one of the most influential earliest syntheses. Others of note are the 2021 US National Academies of the Sciences Reflecting sunlight: Recommendations for solar geoengineering research and research governance, and the 2023 UNEP report One Atmosphere: An independent expert review on Solar Radiation modification research and deployment. Their conclusions are essentially: this needs more research and in the meantime please don’t do anything. That’s why Safeguarding the polar regions from dangerous geoengineering: a critical assessment of proposed concepts and future prospects published this week in Frontiers of Science was such a refreshing change. 

“According to our expert assessment, none of these geoengineering ideas pass scrutiny regarding their use in the coming decades. Instead, we find that the proposed concepts would be environmentally dangerous. It is clear to us that the assessed approaches are not feasible, and that further research into these techniques would not be an effective use of limited time and resources. It is vital that these ideas do not distract from the priority to reduce greenhouse gas (GHG) emissions or from the critical need to conduct fundamental research in the polar regions.”

That’s as near to a smack down as you get in academia. I can imagine the authors reviewing proposals for polar geoengineering and yelling “What the hell do you think you are doing?!”. Before I get into this I need to highlight that lead author Martin Siegert is also an academic at the University of Exeter. I was not involved in the report and have not discussed it with him or any of the other 40 co-authors. I also need to mention that some of the authors of the high-level reports mentioned above are also based at Exeter and they have different views to me on geoengineering as a climate solution. Finally, the Frontiers of Science article is specifically about polar geoengineering, so concentrates on attempts to reduce and even reverse the impacts of climate change on the Arctic and Antarctica.

The Arctic is the fastest warming place on the planet, and along with Antarctica has a crucial role to play in the functioning of the Earth’s climate. The alarming decline in the amount of ice in these regions has given rise to calls from, for example, Cambridge’s Centre for Climate Repair to refreeze the Arctic. This has been a source of great puzzlement to me because I cannot understand how extremely smart people can propose something so extremely foolish as having millions of pumps spraying sea water onto ice sheets, in order to increase ice thickness. How will they be installed and maintained in such a hostile environment? How will they be powered? How will international governance be managed in such a contested area? The response to such questions in my experience is typically to wave them away while arguing that’s why we need to ramp up research. And besides, what do I know, I’m not a polar scientist.

Well the 40 authors of “Safeguarding the polar region…” are polar scientists. So I guess we should listen to them. What they say is unambiguous. They evaluate five of the leading concepts for polar geoengineering:

• stratospheric aerosol injection
• sea curtains/sea walls
• sea ice management–modifying albedo and thickening sea ice
• slowing ice sheet flow through basal water removal
• ocean fertilization.

For all five they find,

“significant issues and risks relating to technological availability, logistical feasibility, cost, predictable adverse consequences, environmental damage, scalability (in space and time), governance, and ethics”.  

It's the report’s scientific and technological feasibility assessments that I find most significant. These people know their stuff. Unfortunately, what may limit the report's impact are some of the wider arguments it makes against geoengineering. For example, it makes the case that the promise of geoengineering risks creating a moral hazard because it allows policy makers to offer promises of future solutions rather than doing the hard work of decarbonisation now. This is not an original argument of course but it’s problematic because it provides an immediate route for people to dispute its findings. They do that by rolling out the risk:risk approach. That’s essentially: yes the risks of geoengineering are significant, but the risks of not doing it, of ‘allowing’ climate change to continue are much greater. I have previously argued that this is not an appropriate way of assessing the risks of geoengineering because it does not actually include the most important risks that come from the ever-increasing consumption of energy and materials driven by continual economic growth.

Another potential a weakness of the report, is that it frames climate policy around 1.5°C. Its invocation of the moral hazard argument is that geoengineering risks diverting attention and efforts away from rapid decarbonisation that could limit warming to well below 2°C. That could have been persuasive a decade ago, but today it cuts little ice because we are in the process of sailing past 1.5°C with record breaking emissions. Ironically, the only way you can continue to claim we are still able to limit warming to no more than 1.5°C is to invoke geoengineering in the form of large-scale carbon dioxide removal.

As temperatures increase, so do the assessed risks of activating tipping points which could lock in even greater change to Earth systems. It’s here that geoengineering proponents often appear, because they hold up these escalating tipping risks as imperatives for at least researching geoengineering because at some point in the perhaps not too distant future, trying to ‘hack the climate’ by sulphate injection may simply be the least worst option.

There is an interesting interaction between the tipping points and geoengineering academic communities. Some of the former are very sensitive to the looming prospects of catastrophic tipping points being used to argue for geoengineering. This is driven by an instinctive sense of horror when contemplating further interference in the complex Earth system by doing things such as injecting millions of tons of sulphur compounds into the high atmosphere.

Much more will be written about proposals to build massive undersea walls to hold up Antarctic ice sheets, drill bore holes in Greenland to pump out lubricating meltwater, or scatter glass beads over glaciers. As informed and erudite I'm sure this will be, I don't think it will be as effective as simply yelling "What the hell do you think you are doing?!”

Plans to refreeze the Arctic have a snowball's chance in hell of succeeding. Authoritative analyses that conclude "needs further research" isn't likely to change that.