However geo-engineering will, I am confident, be used as an excuse to carry on emitting CO2 and avoiding dealing with the fundamental flaw in our civilisation; exponential growth in a finite world. It is dangerous and is a recipe for disaster.
I've recently been blogging about a new pattern of circulation in the Northern Hemisphere that has brought cool wet summers to the UK since 2007. This pattern has also been spotted by scientists who have recently published their findings. Edward Hanna seems to be mainly a Greenland specialist, but James Overland, Jennifer Francis, and Muyin Wang are, by their publication record, some of the leading experts in the study of the Arctic atmosphere. The pattern has been active in summers since 2007, yet it took until 2012 before the scientists published about it. Crucially, I can find no evidence of this pattern being found in GCM modelling studies, the authors of the study examining new pattern of atmospheric circulation do not refer to such a modelling study. Indeed there is one mention of models in the paper: "Coarse scale climate models may not be up to the task of resolving such connections."
So the best guess of three of the top experts in the Arctic atmosphere is that changes in the snowline are driving the process. It's an educated guess, they may be correct, and my citing this example is in no way a criticism of their abilities. However faced with an unexpected change it can take years to identify the change amongst the variability of weather, then more years to identify what processes are driving the change, if more than one hypothesis is available it can take years more to sort out what's really going on and which hypothesis is correct.
Let's suppose that a method of geo-engineering has been implemented, and that it then becomes noted that damaging weather is being experienced in one or more regions. It's already taken years of damaging weather to identify the pattern out of the noise of natural variability, years more to elucidate the most likely cause. How long does it take then to decide how to modify the geo-engineering to deal with the problem it has caused? And what further problems will that cause?
During these years populations are being subjected to flooding, drought, or storms, causing human suffering that was deliberately caused by the geo-engineering scheme. That is in contrast to AGW which proceeds as an unintended consequence of human actions, actions not intended to impact the climate system. What would a moral philosopher have to say about this, more to the point; what would a lawyer advising a group action on behalf of those affected have to say about this?
However these issues aren't what really scares me about geo-engineering.
In my recent post Something Wicked This Way Comes I wrote a paragraph trying to sum up the changes we're seeing now, with about 0.8degC warming, and asked what this means for the future: How bad is it going to get if this is just the start? Now imagine that we've decided to go with geo-engineering to deal with dangerous climate change.
There are three broad groups of techniques available:
- Solar Radiation Management.
- Carbon Dioxide Removal
- Heat Transport
Carbon Dioxide Removal would be costly. At current emissions of about 33,000,000,000 tons of CO2 per year any method to extract CO2 would be costly, in land use, fuel, money, or all of those. Wikipedia lists four candidate options.
All of which have land use or energy input requirements. Clearing more land would place more pressure upon ecosystems, or food prices. Any energy used would have to be non fossil fuel, which would eat into whatever offsets could be made to fossil fuel burning reductions. Overall the whole process would have to not impact the poor (food prices), and would have to be substantial.
This leaves Solar Radiation Management (SRM). Firstly this fails to address ocean acidification, and leaves atmospheric CO2 accumulating. Painting the roofs of whole cities pale colours could induce the sort of climatic effects that have lead to the new circulation pattern, or cold boreal winters, more here. These would likely be highly unpredictable, only fine resolution models would stand a chance of capturing the impacts. Space based solutions are fantasy at present, if used we need to be able to maintain them for millennia. Perhaps the cheapest option would be adding additives to jet aircraft fuels and ship fuels, but again we'd need to keep it up for millennia. (And if any tin foil hatters post about chemtrails and the NWO they'll be deleted without warning.)
Why do I say we would need to keep up SRM for millennia?
Archer & Brovkin's 2006 paper "The Millennial Atmospheric Lifetime of Anthropogenic CO2", PDF, shows that the emissions of CO2 will remain in the atmosphere/ocean system for thousands of years. Their abstract sums up their findings perfectly:
The notion is pervasive in the climate science community and in the public at large that the climate impacts of fossil fuel CO2 release will only persist for a few centuries. This conclusion has no basis in theory or models of the atmosphere/ocean carbon cycle, which we review here. The largest fraction of the CO2 recovery will take place on time scales of centuries, as CO2 invades the ocean, but a significant fraction of the fossil fuel CO2, ranging in published models in the literature from 20–60%, remains airborne for a thousand years or longer. Ultimate recovery takes place on time scales of hundreds of thousands of years, a geologic longevity typically associated in public perceptions with nuclear waste.So if we take any geo-engineering scheme that doesn't involve massive emissions reductions or active draw-down of CO2, we need to keep it up for at least 1000 years, the more CO2 we emit the longer the recovery of CO2 back to pre-industrial will take.
And if we falter...
Let's suppose we take the cheapest option available and decide on SRM, jet aircraft have additives added to fuel. We're shipping more over the Arctic routes during the summer when insolation matters, so we do the same for their fuel. We're successful, we manage to keep temperatures as they are now, maybe even knock a degree off Arctic temperatures. Leaving aside the effect of increasing ice on shipping (having been won over, we start dedicated flights). With each year that we're successful, CO2 builds in the atmosphere, the potential warming builds. Like a person in debt switching credit cards, we delay the inevitable. Just as the Credit Crunch caused so many people to default after years juggling the debt they'd accrued in pursuit of an unsustainable lifestyle: Should we falter we could face decades of accrued warming. But crucially, instead of hitting the planet at the rate happening at present, admittedly fast in geological terms, this warming could hit within years or a decade. Global temperatures have been rising steadily since about 1975, now imagine compressing that, and possibly more, into a decade. That prospect scares me more than just letting the process continued unchecked. Indeed, I'd go so far as to say that one couldn't deliberately devise a better way to unleash a climatic disaster.
I'm not saying we shouldn't try carbon sequestration, but it cannot be at the expense of food, the world's poor already have problems enough getting sufficient food. So before you lecture me about the benefits of biochar, or some other pet scheme to capture carbon, remember....
33,000,000,000 tons of CO2...