Dr Nils Markusson examines the “emergency” argument for creating large scale climate altering technologies to reverse the impact of climate change and finds it wanting. 

Rapid, high-impact disasters caused by global warming seem increasingly likely.  For example, the kind of flooding events that hit the UK this winter will probably occur more often and be more severe.

This is due to our emissions of carbon dioxide and other greenhouse gases, and our seeming inability to stop emitting them.

Wouldn’t it be great to have a technology that could rapidly cool the planet, and avert any future, really serious climate disasters?  Shouldn’t we at least prepare for this eventuality by developing such technologies?

This is the ‘emergency’ argument for the development of so-called solar radiation management technologies.  These technologies could theoretically reflect sunlight back out into space and lower the temperature of the planet and could, potentially, do so very quickly.  In principle, they could therefore be used in response to early signs of imminent climate emergency to prevent it.

However, work by myself and collaborators at Edinburgh University has shown that this emergency argument is untenable, but also that it is unlikely to go away and should be discussed rather than ignored or repressed.

Any use of solar radiation management technology as a response to expected climate emergency would have international consequences and should conform to international law.

Initially it seems that the notion of ‘necessity’ in international law offers a plausible, well specified and tested standard for assessing what would constitute legitimate justification for solar radiation management as a preventative emergency response.

But, solar radiation management fails to meet several of the crucial criteria for ‘necessity’.

In particular, the criterion of ‘grave and imminent peril’ requires that we are able to predict the occurrence of climate emergencies.  It is therefore important to examine the scope for reliable, scientific prediction of abrupt climate change.

The scope for scientific prediction of abrupt climate change is however very limited.

This is not just an issue of doing more research, since some kinds of abrupt climate change are inherently unpredictable.  And even in those cases when prediction is possible, the time it takes to establish scientific facts as well as gain wider acceptance of them in support of action limits the scope for effective forewarning even further.

Common sense suggests that if we can’t predict climate emergencies, the emergency argument for using solar radiation management to prevent climate disaster is undermined.

In practice, unpredictability sustains rather than undermines the emergency argument.  This is because the mere possibility of future disaster is deemed a sufficient rationale for the development and deployment of the technology.  The ambition is to pre-empt potential disasters from materialising, that is to articulate and act on the idea of disaster in the absence of robust evidence of risk.  The emergency argument is therefore hard to refute with reference to that absence of evidence, and works well when there is deep uncertainty as with abrupt climate change.

That it is hard to refute also makes the emergency argument a very tempting one, for those wanting to support development of geoengineering, and the argument is therefore unlikely to go away.

So what – it is just an argument!  Well no, it is a well-established fact that the use of emergency argument tends to close down debate and legitimise lines of action that would otherwise be seen as unacceptable.  And for a controversial and potentially very powerful and dangerous technology like solar radiation management, this is bad news.

The conclusion reached by myself and my collaborators in our recent paper is therefore that ignoring or repressing the emergency argument for solar radiation management is an ineffective and dangerous response.  Instead more effort is required to debate, defuse and disarm emergency rhetoric.


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