Part 2 – GeoEngineering, what is it and why aren’t we talking about it?
In climate circles, as soon as someone raises geoengineering everyone looks at you like you just said ‘Voldemort’. At present the argument for nature based solutions to the climate crisis are complete. There is consensus that we must urgently facilitate and scale nature based solutions, however the question remains, will these be enough to combat the scale of the problem? The rate at which we have put carbon into our atmosphere and polluted our planet must be combated with something equally as scalable and equally as quick. We must consider the very real possibility that nature based solutions will not meet the challenge we face of reversing the keeling curve (5), and returning to save levels of atmospheric carbon dioxide. Regardless of what the probability that nature based solutions will not be enough is, non nature based solutions (geoengineering) must be understood.
Geoengineering is at its simplest, deliberate intervention in the earth's climate system. Critics often call this ‘playing god’, understandably so, arguing that we are dealing with something beyond what should be in our control - the atmosphere, and that there may be many unseen consequences from meddling with our earth's system. However, we have already been geoengineering since the industrial revolution, but in the wrong direction. We have done something so unnatural by raising atmospheric carbon to above 400ppm from below 300ppm, that tragically there is a possibility only something equally as unnatural can combat this. And this is obviously very scary. What I am suggesting here is that we must at least research and discuss the possibility that we might need to consider geoengineering. At present we are unable and unwilling to have this conversation due to the complete lack of research and understanding of geoengineering possibilities.
In the lead up to the 2020 election I had conversations with 5 senior MP’s about Geoengineering (6). Not one of them had heard of it, some thought I was talking about Genetic engineering. Then when I explained it (as explained below), they all had a ‘the floor is lava’ moment with the conversation. The criticism of geoengineering is widespread, it is labelled as a potential excuse to continue to emit or to take away from investment into nature based solutions. It is somewhat the same logic as critics of carbon offsets. It is fair to say geoengineering and carbon offsets can be used as an excuse for climate complacency. Where we are just compiling a greater climate ‘debt’ via geoengineering (7). However, we can’t not invest in technology just because it allows for complacency, otherwise we wouldn't use many technological fixes to environmental issues. The nature of the crisis is such that regardless of emission reductions we need to start heading in the other direction by reducing atmospheric carbon. We cannot let this fear of complacency stop our efforts to repair our climate. So what would happen if we came up with a geoengineering feasibility assessment put together by the best scientists in the world? Do we think their suggestions would have disatorours unseen consequences to the earth system? Lets at least have all the information before reaching this conclusion. I believe we may be able to manage the risk by steadily scaling up geoengineering schemes and by best practice science and risk analysis.
So what would geoengineering look like? And what is the difference between geoengineering and carbon capture? - There are two types of geoengineering, artificial carbon capture (as opposed to nature based carbon capture) and heat reflection, (Methods to reflect incoming shortwave solar radiation).
Examples of geoengineering
Solar reflection - Putting large ‘reflectors’ into orbit to reflect incoming solar radiation. David Keith of Harvard University has done some initial research on solar reflection (8). One of the few geoengineering ideas that has had some research, although very preliminary.
Marine cloud brightening - Spraying sea salt into the atmosphere to create clouds to reflect solar radiation by making clouds denser.
Cloud seeding - Spraying of aerosols and other chemicals to create clouds that will reflect incoming short wave radiation.
Artificial carbon capture - Essentially machines that capture carbon out of the atmosphere and turn it into a solid, see - https://www.climeworks.com
Iron hypothesis - The Iron hypothesis is one of the key ideas that kick-started the geoengineering train. It has largely been proved to be redundant now, however is an interesting example of where science was able to research a geoengineering idea to its full extent and prove it was not effective; and international laws have accordingly prevented any iron fertilisation going ahead. The idea is that the Southern Ocean is very iron deficient and a small amount of iron fertiliser could create large phytoplankton blooms sequestering carbon. Which worked, however the carbon returned back into the water column and other greenhouse gases were released by the phytoplankton having a net neutral or negative effect on atmospheric greenhouse gas budgets.
One important part of the geoengineering definition we have not yet understood is whether it depends on the scale of the activity. For example is artificial carbon capture geoengineering, if you sequester 1kg of carbon like it is if you sequester 1 gigaton of carbon? I will suggest it is irrelevant how much impact it has. If the activity is deliberately reflecting solar radiation or non- naturally sequestering carbon, then it is geoengineering.
There is not one researcher to my knowledge in New Zealand looking full-time into geoengineering, which is odd considering New Zealand has the ninth largest ocean in the world, and many potential geoengineering techniques use our ocean (9). People often reference the fact New Zealand is only responsible for .17% of the world's emissions when arguing against stronger climate policy. However New Zealand could sequester a much larger fraction of the world's emissions through our ocean and could contribute to a very large fraction of global drawdown through leading on carbon capture and geoengineering schemes.
Undoubtedly there will be extensive scepticism to geoengineering and detailed risk assessments needed. Not to mention the international laws around putting something up into space to reflect sunlight. But we must open our minds to the possibility that nature based solutions will tragically not achieve a stable climate. If nature based solutions can get us where we need to go to get to our emission reduction targets, then that's a huge win, but there is a possibility we will need something cheaper and more scalable at pace. Net zero cannot be our goal, we must simultaneously cut all emissions, invest heavily in nature based carbon capture and activate extensive artificial carbon capture schemes. Geoengineering may buy us some much-needed time while we repair our atmosphere if we give it some thought.
5 https://keelingcurve.ucsd.edu
6 Chloe Swarbrick, Paul Goldsmith, Gerry Brownlee, Megan Woods, Chris Hipkins
7 https://www.cam.ac.uk/research/news/opinion-betting-on-speculative-geoengineering-may-risk-an-escalating-climate-debt-crisis
8 https://keith.seas.harvard.edu/news/let’s-talk-about-geoengineering