An April 16 interview on the BBC (mp3) on the topic of geoengineering by Sarah Montague with Ken Caldeira of Stanford and David Keith from the University of Calgary raises some interesting issues about how the climate science community seeks to influence political outcomes through its decisions about what research to conduct and discuss in public.

Dr. Keith was first asked if geoengineering offers a “realistic prospect for a solution to global warming”:

Keith: I think that “solution” is much too big a word. The sort of things we are talking about are not solutions in the sense that they would not compensate for the environmental damage of all of the carbon dioxide we’re putting in the air, but they might still be things that in some bad circumstances we’d want to do to limit the worst damage of that carbon dioxide. So I think of these more as band aids, but band aid is a pejorative word, but it is also something that we use.

Sarah M: And could contribute?

Keith: Yes

After Ken Caldeira recommends doing more research to evaluate the potential effectiveness of geoengineering he is asked whether such strategies could indeed provide “part of the solution”;

Caldeira: Yes, none of these solutions will completely reverse the effect of greenhouse gases in the atmosphere, but as David points out it looks as if many of these schemes have the potential to reduce the consequences of carbon dioxide emissions. . .

The conversation next turned to the political implications of geoengineering, and specifically its effects on what options are considered in debate on climate change.

Sarah M: I suppose the problem with any idea like this [geoengineering] Professor Keith is that you are possibly distracting from the business of reducing greenhouse gas emissions.

David Keith: Absolutely, I think that this has been people’s biggest fear in talking about this at all, that the idea that some of this risk management or band aid solutions are out there might make people less committed to cutting carbon dioxide emissions and I think that was a sort of universal fear that you heard at the conference [of the European Geosciences Union] and among various people who work on these technologies is exactly that.

So, to recap: scientists think that geoengineering has the potential “to reduce some of the consequences of greenhouse gas emissions” but some scientists think that scientists should not discuss the prospects for geoengineering because it will distract from other approaches to dealing with greenhouse gas emissions. Thus, decisions about what research to conduct and what is appropriate to discuss is shaped by the political preferences of scientists. This won’t be news to scholars of science in society, but it should be troubling because it is unfortunately characteristic of the climate science community. I personally have seen this dynamic at work when engaging in discussions of adaptation and also the true magnitude of the mitigation challenge.

Of course, neither Caldeira or Keith are among those who want to limit research or talk about geoengineering, but they obviously are well aware of those people among their colleagues (as am I). The interview ends with an rather glib policy recommendation by Caldeira:

Caldeira: . . . The question of which is better to do, which is more environmentally sensitive, to let the polar bears go extinct or put some dust in the upper atmosphere? And I think that it is not clear that choosing the extinction of polar bears is the more environmentally friendly choice.

Perhaps this question was meant to provoke an intellectual “thought experiment,” but since it wasn’t presented as such, I’d be interested in hearing from Ken or anyone else about any available research that might suggest that geoengineering offers the prospect of altering the probabilities of future polar bear extinction. It is exactly this sort of imprecise, scientifically unsupportable discussion of policy alternatives that the scientific community should avoid.

Finally, let me make my own position clear. I prefer that both research and discussion of geoengineering take place. I am confident that the vast majority of such technologies can be shown to be a very bad idea on the merits of the policy arguments for and against. The one exception I’d suggest is the direct air capture of carbon dioxide, which some people don’t even include as a geoengineering technology. One thing I am sure of is that scientists should encourage political debate over policy options for responding to accumulating greenhouse gases to take place out in the open, involving policy makers and the public, and resist the urge to try to tilt the political playing field by altering what they allow their colleagues to work on or discuss in public. The climate debate has too much of this behavior already.