Final thoughts....

Over the course of several weeks, I have tried to unpack the term ‘Geoengineering’ and understand its potential as well as its flaws. A variety of Geoengineering options have been presented and ideas/issues surrounding this field have been highlighted. So after all this research, what is to be learned?

Firstly, it is not enough! More research is needed. Figure 1 shows the number of research papers published on Geoengineering per year. According to the Economist, this is just more than 50 papers for 2010. While this may sound like a large amount, this blog has addressed at least 8 different geoengineering options, and there are still more to consider. Therefore, when these 50 papers are stretched over the wide variety of Geoengineering proposals, this indicates that there is very little depth in this field. And this was definitely found when conducting research....there were a lot of great ideas, the basic science was put forward but there was little information on testing and the full impacts of each proposal. Lawrence (2006) found that although you could find a large number or proposals, it takes a great effort to determine the unintended consequences of each option. Many academics agree that research into Geoengineering is still in its infancy (Victor et al, 2009).

However, when comparing the available Geoengineering options and evaluating their potential to offset C02 emissions, it was found that some options could be viable. By simply adopting better forest management, investing into afforestation, disposing of waste differently to produce biochar, and fitting large industrial plants with the technology to capture and store carbon, this could make a significant contribution to reducing emissions. These are activities that could be easily incorporated into society, and could be extremely useful in buying us more time to invest in more long-term solutions.

Figure 1:

Personally, I have found that through learning more about the variety of Geoengineering options available, I have broken down those pre-conceptions I had about the field. I originally viewed Geoengineering as a radical, destructive, field of ideas that could make things worse. And although there are risks, some options should be prioritised and heavily considered.

However, what the research does show is that despite the growing interest in Geoengineering, all the academics interested in this field explicitly state that there is no replacement for cutting emissions. Geoengineering will never be the answer to all the world’s problems. It doesn’t solve the problem of Ocean Acidification and many of the options, with the exception of sun shades and stratospheric aerosols, are unable to fully offset C02 emissions unless strong mitigation occurs. Therefore, if the international community doesn’t put all its efforts into curbing emissions then we will be faced with too worrying futures: One future may involve extreme temperatures, higher sea levels and a greater frequency of climatic events such as hurricanes, storms. While the other future may see the use of stratospheric aerosols, that were used as a last resort to prevent the climate system from destabilising. This future will have a very different climate, may have a lot more pollution, a depleted ozone, and could look very different to today...but the biggest worry is that we may never really be able to predict what this future could look like....

........taking this perspective, I feel the answer to the poll question that I asked right at the beginning of the this investigation, is clear: NO we should not abandon measures of mitigation, however, as a last resort we should make small investments into a handful of geoengineering options in order to give us more time to adapt and invest in long-term solutions....but this is just my opinion...I have tried to give you all the facts...what do you think?

Are we playing God?

Let us go back to the definition of Geoengineering: ‘the intentional modification of the earth’s climate system’. Humans/people have been modifying the environment for years...some deliberate e.g. deliberate fires/building of dams, while some not intentionally e.g. the global-scale transformation that has occurred since the 1850s (Schneider, 1996). Some scientists believe that humans have impacted the earth to such a significant extent that a new geological era should be created, specifically acknowledging the impact that humans have had on the Earth’s ecosystems: the Anthropocene (Crutzen, 2002).

The man who first coined the word ‘Anthropocene’ in 2000, nobel prize winner Paul Crutzen, is also the man who has written numerous papers on the Geoengineering proposal whereby sulphur is injected into the atmosphere. Crutzen believes that we are not doing enough to mitigate GHG emissions, so much so that we need an escape/back up plan; in his mind this is Geoengineering.

So people like Paul Crutzen, may argue that we have already modified the earth; that we have already ‘chosen’ to geoengineer our climate system through the use of fossil fules, so what is the matter with a little more modification? And when scanning the literature and learning about the variety of Geoengineering proposals, I found myself thinking...we are just replicating and enhancing natural processes anyway, aren’t we?

But what makes the topic of Geoengineering so politically radioactive? Is it just the fact that it may dampen efforts to cut emissions? Or is there a moral/ethical aspect as it means we are intentionally modifying nature to suit our needs? By adopting a future of Geoengineering are we saying that we know everything about the climate and how the system works? Are we being too arrogant to think that we have complete control over nature? Society used to hold this view...it led to the building of dams, the modifications of rivers, the building of vast sea walls...the list goes on...but many of these large projects ended in failure. We only have to look at the Aral sea, the Yangtze River or the government’s response to rising sea levels to see this. Would Geoengineering be any different?

I personally feel that many people are resistant to fully acknowledge and consider Geoengineering as a viable solution to climate change as they know that it is still an area that scientists know very little about. We are not ready to say that we know enough about climate to allow us to control and modify it. However, if other scientific risky endeavours, such as genetic engineering and high-energy particle accelerators, have been researched in the past, I think it is now vital to conduct further research into the Geoengineering field (Victor et al, 2009). If anything, it could give us a better understanding of how the climate system works. So I think it is time to take Geoengineering out of the closet in order to better control the experiments and to ensure that all the negative consequences of each option are prevented...otherwise this field really is going to continue to be a ticking timebomb!

Any winning contenders?

This blog has considered a wide variety of Geoengineering options....so what is the verdict? Are any of them a viable option for solving climate change?

Let us firstly look purely at the potential of each option: To compare Geoengineering options, the potential of each proposal to cool the climate is quantified in terms of radiative forcing (RF). RF describes any imbalance in the Earth’s radiation budget that could be caused by human intervention or natural processes. Once a RF is applied, then the Earth’s radiation budget will usually adjust itself and this will be seen through changes in global temperatures. IPCC (2007) states that the present anthropogenic RF is equal to 1.6 Wmˉ². This is the target that many Geoengineering proposals have adopted to counteract. Are any successful? However, what if mitigation continues to be unsuccessful? Lenton and Vaughan (2009) postulate that without mitigation, anthropogenic C02 forcing could reach approximately 7 Wmˉ² by the end of the century. And even with strong mitigation, anthropogenic RF may still exceed 3 Wmˉ². Therefore, which Geoengineering option/options could counteract this?

Placing sun-shades in space ad increasing planetary albedo through the injection of aerosols into the stratosphere are the only two options with the potential to counteract >3 Wmˉ². Moreover, these options could even be scaled up to counteract further anthropogenic RF. The RF potential of enhancing cloud albedo could also achieve 3 Wmˉ² globally, but the effects would be regional and patchy. This is also true for injecting aerosols, depending on when the aerosols are injected. These shortwave measures appear to have the most potential to roughly cancel the anthropogenic C02 RF, as long as strong mitigation measures are also implemented. The remaining measures such as enhancement of the albedo of deserts, urban areas, crops, grasslands etc, could be used in combination and could achieve a partial cancellation of the anthropogenic C02 RF.

Long-wave measures that influence the carbon cycle through the capture of CO2, either by plants, biochar or chemical means, could be used in conjunction to achieve a RF of approximately 2.5 Wmˉ². These options appear to be much more effective compared to ocean fertilisation, where tests have shown that this option only has a RF of 0.23 Wmˉ² (Lenton and Vaughan, 2009).

Figure 1:

So from looking purely from a Geoengineering potential perspective, air capture and storage, the use of sun-shades and stratospheric aerosols, appear to be the options that would induce the greatest radiative forcing...this can be seen in Figure 1. However, what about the risks....While the use of sun-shades and injections of aerosols may have the most potential, they are also the most risky. If deployment is suddenly stopped then rapid warming could occur (Wigley, 2006) (see post: ‘Geoengineering Projects – are they viable of just plain crazy!’). However, carbon cycle engineering carries less risk associated with failure. Therefore, in my opinion, air capture and storage along with afforestation and the use of biochar appears to be the best option. Compared to the remaining Geoengineering proposals, these options are the least risky, and when used in combination could be equally successful as the short-wave options. Moreover, they have the support from the IPCC and afforestion and bio char could also provide other benefits to society not just carbon sequestration. However, their effectiveness is over a long time scale. Furthermore, these options could only counteract 3 Wmˉ² of the anthropogenic C02 RF, what happens if society fails to mitigate emissions? What about the remaining 4 Wmˉ²? This is why many academics are emphasising the need to investigate the option of stratospheric aerosols (Lawrence, 2006; Schneider, 1996; Lenton and Vaughan, 2009; Victor, et al., 2009; Govindasamy and Caldeira, 2000; Matthews and Caldeira, 2007). Even though this option does have a significant risk element, it may be society’s last resort if rapid climate change occurs. The question is, is there any harm in having an insurance policy? Does it mean we will go out and take more risks if we do?

Geoengineering: Ticking timebomb

Hi everybody,

Today I am going to explain my reasoning behind the dramatic title of this blog. When first conducting research into this field I found that many of the academic papers I came across were titled in an equally dramatic manner, the majority of which with rhetorical questions  such as:

•          ‘The Geoengineering Dilemma: To Speak or Not to Speak’ (Lawrence, 2006)
•           ‘Geoengineering climate change: Treating the symptom over the cause’ (Kiehl, 2006)
•           ‘The Geoengineering Option: A Last Resort Against Global Warming’ (Victor, et al., 2009)
•           ‘Geoengineering: Could – Or Should- We do It?’(Schneider, 1996)

This was the first reason for the dramatic title, as right from the onset, even before reading the papers, it can be seen that the topic of Geoengineering is controversial, debatable and is surrounded by ethical and moral issues. Further reading then lead to the creation of the title for this blog as it became apparent that the prospect of Geoengineering could be compared to a ticking timebomb in so many ways: 

1. Even discussing it could have catastrophic impacts as it could cause people to question whether or not they should cut emissions if there are alternate solutions. Therefore even discussing Geoengineering options could give politicians, companies and people an excuse to carry on living their life without fear of the repercussions (Victor, et al., 2009).
2.  Deployment – this has been briefly touched upon in previous posts. Many of the options e.g. ocean fertilisation, enhancing the cloud albedo, injecting aerosols into the atmosphere – these could be carried out by individual countries or even private companies. Therefore, unlike cutting emissions, it does not require a collective effort to be deployed. If one government was to decide they no longer want to cut emissions and that they would prefer to adopt a less costly approach e.g. injecting aerosols (see last post) then they could do so. However, the impacts that this may have are still heavily unknown! (Victor, et al., 2009).
3. It is difficult to police – if a government or private company was to adopt a geoengineering approach e.g. injecting aerosols or enhancing cloud albedo, then it would be difficult to determine who initiated the action (Schneider, 1996).
4.  What is the boundary– unlike testing in other scientific fields that are deemed risky e.g. GM foods or nuclear weapons or nuclear power, although some of the impacts of these activities may be difficult to localise, it is still easier compared to Geoengineering approaches. Where is the line? At what point or amount does injecting aerosols into the atmosphere move from being an experiment, to significantly altering the climate of a region? Ocean fertilisation is easy to limit, but approaches that involve the atmosphere such as injecting aerosols or enhancing cloud albedo, become difficult to limit (Lawrence, 2006).

All of these factors make the Geoengineering field a very dynamic; one that as climate change continues, this field will gain more and more attention. However, to ensure that the negative consequences of Geoengineering do not occur (that the bomb doesn’t go off), a governing body is needed to monitor and regulate all Geoengineering activity. Currently, different projects have captured the attention of different bodies such as the IPCC, US Department of Energy, NASA, UNFCCC, Natural Environment Research Council (NERC) and the Royal Society. This shows that a variety of bodies are interested in Geoengineering, but due to its global nature, an overarching body is required to ensure that the symptom to climate change does not turn out to be worse than the cure.

The Economics behind Geoengineering

Let’s look at the idea of injecting aerosols into space more closely...(Previous posts go into the science, today we will be looking at the cost because as we know money matters!). One of the reasons why research into Geoengineering approaches is on the rise is due to the financial cost of cutting GHG emissions. Could Geoengineering approaches be more cost effective?

David Keith, from the University of Calgary, commissioned a study using a company that makes high-altitude drones. The study showed that small airlines could be newly designed in order to be capable at flying at altitudes of 20-25km and distributing tens of thousands of sulphuric acid vapour. It is estimated that approximately 80 such planes would be required every year to inject the vapour into the atmosphere and cool the Earth by a degree or two. This goal could never be achieved by purely cutting GHG emissions. The planes would have an operational lifetime of 20 years, and would cost approximately one or two billion dollars (Economist, 2010).

The study conducted may be deemed as a breakthrough for such Geoengineering projects...as it proposes that a couple of billion dollars a year spent on sulphur would be enough to offset the warming. If comparing this option with the option of moving to low-carbon energy sources, which would require hundreds of billions of dollars.....then for any politician it’s an easy choice to make! It maybe so easy that the potential risks of the approach could be entirely forgotten!

Locking away the carbon

The IPCC has acknowledged that along with other mitigation options, Carbon Capture and Storage (CCS) could make significant reductions to GHG emissions. Geological storage is the preferred option as there are still large amounts of uncertainty regarding storing CO2 in deep oceans.

Carbon capture firstly involves capturing the CO2 directly from emission sources e.g. power plants and large industrial plants. The C02 is then dehydrated, compressed and transported and then finally injected into a reservoir. The capture and transportation is relatively easy, it is the storage part that is providing an obstacle and is causing concern.

Underground C02 of any kind must take place in sedimentary rock. Figure 1 shows the sedimentary basins of the world where CO2 could potentially be stored. C02 must also be stored deeper than 800m below the surface. Oil fields, gas fields and saline formations have been proposed as storage sites (Marchetti, 1977). Approximately 30 to 50 million metric tonnes of CO₂ are injected annually in the United States into declining oil fields. Both the report from the IPCC and House, et al. (2006) conclude the storage capacity for C02 is expected to exceed available fossil fuel reservoirs. Lenton and Vaughan (2009) postulate that in the long-term, carbon capture and storage could potentially sequester >1000 PgC.

Out of all the Geoengineering options discussed, the option of CCS appears to be the most researched, tested, implemented and supported. The backing and investigation by the IPCC has provided confidence in this option. In 2008, a German Power Plant run by Vattenfall conducted a pilot study through creating a CCS power plant. It was found that this plant reduced emissions of C02 by 80-90% compared to a power plant without CCS (IPCC, 2005). However, as with all of the other Geoengineering options discussed, there are downsides....firstly, capturing and compressing CO2 requires large amounts of energy. The amount of fuel required to operate a CCS plant would need to increase by 25-40% (IPCC, 2005). Secondly, there are numerous health and safety risks regarding storage, and many long-term uncertainties. For example, a big uncertainty regarding the use of deep oceans for C02 storage is the impact that this may have on ocean acidification.

Compared to many of the Geoengineering options investigated, CCS is the first one that I feel confident about. But is this because it has the backing of the IPCC? Compared to the other options were a few academics are leading the research, the IPCC appears to be taking point, bringing a variety of academics together to discuss and research CCS...so maybe Geoengineering is not all bad news!

Biochar? A silver bullet?

Biochar is created through the slow decomposition of organic matter at high temperatures in the absence of oxygen. Normally the organic matter would decompose rapidly after the vegetation/plant matter dies, releasing CO2, however, instead of allowing the plant matter to decompose, the process of pyrolysis can be used to sequester the carbon.

The use of biochar for carbon sequestration is a novel idea (I had never heard of it until I conducted this investigation!) Biochar can draw carbon from the atmosphere, locking it away for thousands of years, making it a long-term carbon sink (Winsley, 2007). Global analysis reveals that approximately 12% of terrestrial carbon emissions could be offset by biochar (Lehmann, et al., 2006). Moreover, by burying the biochar in the soil, this increases the fertility of the soil. Consequently, as with afforestation, the creation of biochar is another option that many land owners and farmers are pursuing as biochar can also be used to earn carbon credits. However, the disadvantage of biochar is that involves burning vast areas of natural habitats and ecosystems. If biochar was heavily integrated into the carbon markets then what would this mean for our natural ecosystems?

When the idea of biochar first came about, many referred to it as the ‘silver bullet’, seeing it as a method to utilise waste in a way that allows society to offset emissions. However, the extent to which emissions are offset is limited. Lenton and Vaughan (2009) suggest that by the 2060s a saturation point will achieved if biochar is fully adopted as a way to sequester carbon. Therefore, this shows that this option is difficult to scale up to a level that will make a significant impact to carbon emissions.

Overall, research shows that biochar can store large amounts of carbon, it is stable and can last a very longtime, so it can even be termed as a ‘permanent’ carbon sink. However, what worries me is the conflicting results found regarding the impact that biochar may have only soil. Some scientists argues that is beneficial and increases the productivity of soil, while others argue that it increases the pH of soil and could be damaging (see video showing experiment with biochar). There is concern that companies may start to heavily invest in biochar through conducting pyrolysis on an industrial scale in order to gain carbon credits. Before this happens we need to ensure we know the effects that biochar will have on our soils; especially since that once it is mixed with the soils, it will be there for a very long time...