In a few months the Rio +20 conference will be held. This means that 20 years have gone since world leaders agreed on an unprecedentedly ambitious programme for global sustainability – including the first attempt to lay foundation for a global fight against climate change. During these 20 years, much has changed – unfortunately, mainly to the worse. We still find ourselves on the business-as-usual emissions trajectory – in other words, on collision course. Understandingly, this feeds calls for alternative approaches and solutions. One of them that gains ever more prominence is: geo-engineering.
What is overarchingly being called geo-engineering is a rather wide field of approaches. “Soft” examples are massive white-painting of roofs and roads (to increase the Earth’s albedo) or afforestation which is also sometimes viewed as falling into the geo-engineering category. In the following discussion I am going to focus on more invasive proposals. These are, among others:
- artificial brightening clouds over oceans to increase their reflectivity (the idea is to build unmanned ships that would cruise over the oceans and spray fine sea water into clouds) – the so-called cloud whitening;
- spraying sulfur dioxide into the atmosphere (using airplanes or balloons) – it would react with water vapor to sulfur acid that is a strong coolant (as already experienced on a small-scale when it was estimated that sulfur emissions from China’s coal plants have had a global cooling effect in recent years);
- placing mirrors into space to reflect part of the incoming solar radiation and thus reduce radiative forcing – so-called Space sunshade;
- iron-fertilization of the oceans to increase the reproduction of phytoplankton that is an important absorber of carbon dioxide.
Just to name a few of the most widely discussed proposals. All of them have one important commonality – they represent attempts to protect us from further warming without having to rely on curbing greenhouse gas emissions. At the same time, they are purposed, deep interferences with Nature.
The first, most “prosaic” problem of geo-engineering solutions to climate change are their immense costs. The ideas described above are only ideas – to make them feasible, applicable solutions, one would need a lot of time and resources to be devoted to their further development. Not to mention the huge costs of actual deployment. However, this is still a rather minor argument against geo-engineering, as I will discuss next.
The main issue here is our (lack of) understanding of the complex natural systems surrounding us. Climate change has been caused by human interference with Nature. This interference was not intended, of course – we have been burning fossil fuels and cutting forests for other purposes. In the beginning, we just were not aware of the consequences. And now our systems depend so heavily of fossil fuels that we have terrible difficulties to stop the dangerous interference.
Geo-engineering is interference with Nature as invasive and far-reaching. However, it is intended. Proponents of geo-engineering believe that we know enough (or that we at least can acquire sufficient knowledge) to cure the problem without causing a new, probably worse one. But do we? There are numerous examples in the more recent history of science that have shown that we don’t understand Nature’s complexity properly (be it the unexpected ability of pests to adjust to GM food toxins, be it nuclear waste that turned to be much more problematic than initially thought etc.). Furthermore, in the case of climate change we have not much time for studying (not to mention the impossibility of small-scale experiments in most cases) – meanwhile, there are many natural cycles and mechanisms that could be adversely affected by geo-engineering: precipitation patterns, marine nutritional cycles and others. It is very risky and, indeed, naive to assume that we are able to foresee all possible repercussions of the interference in question. But if we don’t, at this scale we run the risk of creating problems even more profound than the one we would like to solve.
This is particularly important for the proposals that would affect the energy balance of Earth (mainly by lowering the amount of incoming solar radiation) – once we started, we couldn’t just stop injecting sulfur into the atmosphere or vaporizing sea water. If we would stop such a process abruptly, without in the meantime having lowered greenhouse gas concentrations significantly, the effect would be runaway warming with terrible consequences for human and natural systems.
Furthermore, many geo-engineering proposals provide (alleged) solutions to one problem only – that of warming. They don’t affect others, especially ocean acidification that may in the long run be as problematic as warming.
I think that the arguments presented here suffice to reject geo-engineering as the solution to climate change. However, considering our apparent failure to agree on curbing greenhouse gas emissions despite all the evidence that we are approaching dangerous tipping points, some scientists call for investments in geo-engineering research “just in case”. Since these solutions are believed to be fast applicable, they may provide an “emergency exit” or a kind of insurance police. However, this argument, put forward by the climate scientist Ken Caldeira, among others, has one significant flaw. As I already mentioned, R&D into geo-engineering is likely to be very expensive. Thus we would run the risk of detracting resources from more conventional approaches to tackling climate change – be it investments in green technologies or in human development to preserve carbon sinks (particularly tropical forests).
So, is geo-engineering a viable solution to climate change? I don’t think so. Moreover, I think that we should keep our hands off these proposals. Their prospects are not at all clear, but their costs and dangers appear far too large. Investment in geo-engineering R&D, if any, should be kept low to prevent crowding-out effects. Instead of further playing with Nature, humanity must realize that we don’t understand it properly and that we, on the other hand, are fully dependent on it. If we don’t stop harming the Earth, we may end up in a world not suitable for us to live in any more.