SRM: In space ...

Reading up on this aspect of SRM has been somewhat surreal, with phrases such as ‘lunar glass’, ideas inspired by Saturn’s rings, not to mention the immense scales (temporal and spatial) and quantities necessary to reduce solar insolation by the 2% that estimations state will counteract CO2 induced climate warming.  The prospect of taking the engineering power of man beyond the confines of our own planet is also a daunting prospect (I actually find this idea terrifying, and can’t help the images of Futurama, Star Wars and Dr Who reverberating round my head!).  How do people feel about blasting 10 trillion reflective discs, 1.5 million km into space (Royal Society, 2009) … 1 million at a time … every minute … for more than 30 years … ? – this sounds crazy but the science behind this is real!


How would it work?

One thing is sure, that sun shields would be effective.  By placing reflective or refractive material, be that discs or dust particles into orbit around the earth, the solar energy entering the Earth’s system will be reduced.  There is no physical limit on the extent of reduction (unlike other SRM methods which I’ll cover later), this may become very important if the critics’ fears are realised and geo-engineering diminishes societies desire to cap and reduce CO2 emissions; the more CO2 in the atmosphere, the more solar reflection/refraction is required, thus in this scenario, opportunity for expansion is crucial.


Feasibility?

This method, however, becomes less feasible when the logistics are considered.  The cost of implementing and maintaining such technology is posing to be a difficult balance.  The mass of sunshields is proportional to solar reduction and the cost of launching increases with mass.  Subsequently, various technologies have been developed such that a smaller mass of sunshields can produce the same solar degree of reduction, but these technologies are dramatically more expensive to engineer, thus until in-situ space production is possible, this remains a drastically expensive option (McInnes, 2010).   The expense of a proposal such as that posed by Angel (2006) is estimated to cost in the region of $100 billion per year, which exceeds current global financial investments in renewable energy technologies by an entire order of magnitude (Robock, 2008).  This solution is financially unfeasible.

This method also contradicts claims that SRM can be used as a quick fix in a climate emergency.  As highlighted earlier, it is evident that initiation of such technology will take decades to implement.  Thus, if this option is further explored, it suggests that we’re committing ourselves to a future of climate manipulation, rather than preparing ourselves for an emergency.


Risks?

Such engineering may lie outside the Earth’s system, but that doesn’t mean it evades environmental side effects.  These include: ozone depletion, changes in regional climate and reduced primary production, it could even compromise the efficiency of renewable solar energy capture.  Modelling these methods has been explored, however, not too a degree adequate enough to fully appreciate the extent of the possible side effects.  One model by Lunt et al. (2008) in comparison with pre-industrial climate, describes significant temperature reductions at the tropics and warming at high latitudes resulting in a reduced latitudinal temperature gradient.  Subsequent reductions in sea ice were also simulated, along with intensity reduction of the hydrological cycle, intensification of Atlantic Ocean overturning and less variability in ENSO.  That said, the authors claim that this deviation from pre-industrial climate is less than we're experiencing in a climate warmed by CO2.

Conclusion:

These methods are imaginative and exciting, but completely unpractical, for financial and logistical reasons if not due to the possible side effects. 

SRM...

Okay so just a brief blog to give you some idea as to where I’m going with the next few posts (subject to additional blogs if I come across any news worthy items etc).  I’m going to get stuck into the SRM debate, discussing each of the core methods:

·      Space-based methods

·      Increased stratospheric albedo

·      Increased atmospheric albedo

·      Increased surface albedo

Each requires individual consideration, as the cost, feasibility, effectiveness and potential risks are method-dependant according to the technology required and the way in which they can potentially disrupt the Earth's system (The Royal Society, 2009).

Working my way from the outside in, first up for scrutinisation are the space-based methods …

Illustration by Stephanie McMillan @ Code green

Public understanding...

Since global warming and geo-engineering are such contentious issues, it is important that the debate is opened up to a more public forum for discussion.  This is a particularly pressing necessity at present as geo-engineering is increasingly progressing towards testing these ideas (if a last minute hesitation regarding social implications hadn't emerged, SPICE project testing would have begun earlier this month), and as it stands are going ahead without much appreciation for how the wider public feels about such initiatives. 

In my last brief blog I highlighted the article in the Guardian, which claimed that there was  public support for geo-engineering.  I have since looked at the research paper it was referencing (Mercer et al., 2011), and largely what I took from the paper, is not so much support, but the lack of public understanding of geo-engineering.  At the onset the survey identified that less than 24% of the 2893 participants had actually heard of either geo- or climate-engineering, and that only 8% were able to adequately describe geo-engineering.  As the authors state, this is higher than previously anticipated, but it still strikes me as an unacceptable level of understanding if these large-scale global climate manipulations are to be given the go-ahead.

This also poses another problem regarding the nature of this survey; lack of prior knowledge begged the need to provide a brief explanation of the climate system, SRM, its benefits and risks.  The paper acknowledges the potential for bias (as the three academics concerned are certainly pro geo-engineering), and states that every effort was made to provide neutral information.  However, 38% of the participants felt the questions and information were biased in favour of SRM, with only 2% feeling as though it were biased against.  The need for inclusion of public opinion requires such surveys; on the other hand, whilst public understanding remains so limited, the value of such studies will be compromised.  It would be interesting to see the result of a survey undertaken by academics opposing SRM, whether the subtle biases inevitable in their study would produce vastly different results. 

Here is a brief summary of some key results:

• 72%, to varying degrees, support furthering understanding of geo-engineering
• This support nearly halved when considering actual deployment, coupled with an increase in uncertainty amongst participants.
• 64% of participants agreed that humans should not be manipulating climate.

I’d like to highlight the third and final statistic; nearly two thirds of participants agreed that humans should not manipulate climate, which in light of the support for research and implementation suggests that a proportion of participants therefore feel that circumstances dictate it necessary that this agreement be waivered.  This highlights one of the key points raised by Gardiner (2010), that the ‘perfect moral storm’ posed by climate change, provides ‘morally exceptional circumstances’ perfectly suited for moral corruption, thus something deemed unacceptable (climate manipulation), can become acceptable (geo-engineering).  

BBC: 72% of people support SRM geo-engineering ... or do they?

Today the BBC featured an article that shows geo-engineering to be in public favour!  It discusses the newly published study by Mercer, Keith and Sharp reporting the results of an internet-based survey of 3105 people across USA, Canada and UK.  The BBCs immediate claim states that 72% of participants 'support' SRM; eventually it gets round to informing the reader that 'support', in this case, regards the research of SRM and not necessarily implementation ... very different levels of support!  This study promises to be an interesting read! Considering the known bias of the academics running the study, I particularly look forward to checking out the nature of the survey and the way in which they have interpreted the results, after all 72% is a high level of support from what I suspect isn't an entirely clued up public ... personally, before starting this blog I can honestly say I knew awfully little about geo-engineering, and I still feel I have a lot to learn before making any conclusions as to how I feel about it!

... I'll check out the study and report back on what I find! 

Illustrated: Geo-engineering methods

Adapted from image by G360 @ University of Exeter

This diagram illustrates some of the various geo-engineering methods which have been proposed, green is indicative of CDR methods and yellow of SRM.

Understanding geo-engineering …

Before I sink my teeth into the debate at hand, perhaps I should first clarify what is meant by the ambiguous term “geo-engineering” …

The experts offer the definition “the deliberate large-scale manipulation of the planetary environment to counteract anthropogenic climate change" (The Royal Society, 2009); for me this definition offers very little clarification as to what geo-engineering actually involves, to do so requires a bit of background knowledge about the Earth’s energy balance:

Much of the solar radiation that reaches the Earth’s surface is absorbed (but not all – this becomes important later!) and re-emitted as warming infrared radiation.  Although, not all the re-emitted infrared continues on its path beyond the Earth’s atmosphere, a proportion is retained in the atmosphere by greenhouse gases, a natural and necessary occurrence (else the earth would be pretty cold right now!).   However, burning of fossil fuels for example has increased the concentration of greenhouse gases, thus the atmosphere is retaining more infrared radiation and the world is getting warmer!

So what do we do about it?  

Well, if your rooms getting too hot what do you do? You have two options:

·      Turn down the thermostat and reduce the heat energy going in

·      Crack open a window and allow more heat to escape. 

…It’s simple.

These basic ideas exemplify how geo-engineering aims to re-adjust the Earth’s energy balance such that less infrared radiation is retained within the atmosphere.  Thus geo-engineering concepts fall into one of two categories: solar radiation management (SRM) which reduces the energy going into the climate system and carbon dioxide removal (CDR) which allows more heat to escape.

Solar Radiation Management (SRM)

SRM alters the energy balance of the planet by increasing its albedo, directly reducing the amount of solar radiation absorbed by the Earth’s surface and the consequential amount of warming infrared radiation emitted into the atmosphere. Such manipulations span from proposals intent on increasing the proportion solar radiation that is reflected from the Earths surface, to reducing the amount of solar radiation penetrating the atmosphere entirely.  SRM is very much the centre of the geo-engineering debate, with pro geo-engineering scientists (such as Ken Caldeira, David Keith and Paul Crutzen) portraying such technology as a quick fix in the event of a climate emergency, due to its potential for maximum efficiency and effectiveness (supposedly its cheap and easy as well!).  Conversely, the geo-engineering sceptics are up in arms about such manipulations that don’t alleviate the high concentration of atmospheric C02 and pose the threat of further distorting our climate system.  So should we put on our ‘seatbelt’ in anticipation of a climate crash as posed by Caldeira? As tempting as this might be, would we simply be relieving the symptoms instead of finding a cure? – These are kinds of discussions I’m keen to explore!

 Cardon Dioxide removal (CDR).

CDR, of the two, is regarded as the more sustainable option, working directly to correct the excessive concentration of C02 in the atmosphere.  It stands to reason that this would reduce the greenhouse effect, inducing cooler temperatures by enabling more infrared radiation to escape.  This option looks far more appealing as it directly addresses the primary cause of climate change and has fewer climatic uncertainties.  The downside, however, is that this option can be costly and by no means a quick fix, delays in climatic response mean that this type of approach needs to be implemented fairly quickly if we are to continue burning fossil fuels at the current rate!

So the debate thickens … do we develop and implement geo-engineering technology? If so, do we implement CDR and/or SRM? I warn you, don’t hedge your bets too soon, as I’m going to delve further into some of the utterly bizarre and brilliant techniques that have been proposed.

Illustrated: A bit of geo-engineered humour!

Illustration by Stephanie McMillan @ Code green

Introduction

'Global warming' and 'climate change' have proven to be commonplace terms for 21^st Century.  After decades of shamelessly pumping greenhouse gases into the atmosphere, we are now seeing an ever-increasing acceptance of the notion that such actions are, in fact, altering the natural function of the Earth's climate system.  This isn’t to say that there aren’t anthropogenic climate change sceptics, but there is a great deal of evidence that for many others, and myself, puts their doubts to rest.

Many consider this the dawn of a new stage in the Anthropocene, a not yet formalised, but commonly referred to, geological epoch characterised by the shear extent of human influence.  This verging third stage proceeds the industrial revolution (stage 1) and the great acceleration of the 21^st Century (stage 2).  The former saw the emergence of fossil fuel driven industry as the dominant form of human production for the first time in human history, whilst the latter describes its rapid expansion and intensification (Steffen et al., 2011).  This stage three is a time for reflection, self-awareness and most importantly difficult decisions.  We are faced with a future climate problem of unknown dimensions (the outlook is bad, but the complexity of the earths climate system dictates that the true timing and extent will likely remain unknown until it is inevitably too late), yet there is no concrete plan of action to adequately prevent, delay or manage either the cause, through mitigation, or the symptoms, through adaptation.

And thus I present to you the pressing need to really consider our options surrounding the highly contested solution of geo-engineering, and the potential it has to actively optimise global temperatures to what is arguably a more 'natural' state, or rather an artificial pre-industrial state.

Should we research and develop geo-engineering for future implementation?   

Through this blog I intend to explore what geo-engineering actually is and what it encompasses, the rationale behind its implementation, the potential environmental risks, as well as the legal, ethical, social and political repercussions of implementing, or even developing, such solutions.

To keep track of how responses change in response to the various topics to I'm going to cover, at the end of each post theres a chance for you to indicate how the post has influenced your opinion towards geo-engineering!