In this week’s Nature Dan Sarewitz and Richard Nelson discuss three rules for technological fixes and then apply these rules to the air capture of carbon dioxide. In a companion piece, Nature also has a very interesting Q&A on air capture, showing that quietly, the technology is moving forward.

Here are the rules for a technological fix:

I. The technology must largely embody the cause–effect relationship connecting problem to solution.

II. The effects of the technological fix must be assessable using relatively unambiguous or uncontroversial criteria.

III. Research and development is most likely to contribute decisively to solving a social problem when it focuses on improving a standardized technical core that already exists.

They then apply the rules for a technological fix to stabilization of carbon dioxide concentrations, focusing of the air capture of carbon dioxide:

What are the prospects for a technological fix? In principle, stabilizing atmospheric carbon-dioxide concentrations at levels deemed acceptable by climate experts can be achieved through radically reduced emissions or through direct removal of CO2 from the atmosphere. Most discussion and effort focuses on the former. The suite of promising possibilities for reducing emissions — from nuclear fission, to photovoltaics, to on-site carbon capture and storage — offers attractive targets for R&D investments7 consistent with Rule III: existing technological capacities can leverage continued improvement. Nevertheless, successful transition to a low-emissions energy system requires effective management across all sectors of society and all uses of CO2-emitting technologies. Within this system, no particular technology fully encompasses the go of the process — eliminating CO2 in the atmosphere — just as no particular teaching technology encompasses the go of teaching children to read. Rule I is violated.

Moreover, because emissions-reducing technologies will compete with existing energy technologies supported by entrenched interests, and because there will be competition between the emerging technologies, we can expect ongoing technical and political debates about efficacy of specific technologies, as seen for biofuels today — a violation of Rule II. System-wide progress is therefore likely to be buffered by political processes similar to the ones that frustrate progress now.

In contrast, direct removal of CO2 from the atmosphere — air capture8 — satisfies the rules for technological fixes. Most importantly, air capture embodies the essential cause–effect relations — the basic go — of the climate-change problem, by acting directly to reduce CO2 concentrations, independent of the complexities of the global energy system (Rule I). There is a criterion of effectiveness that can be directly and unambiguously assessed: the amount of CO2 removed (Rule II). And although air-capture technologies have been remarkably neglected in both R&D and policy discussions, they nevertheless seem technically feasible (Rule III)9, 10, 11.

Our rules do not allow us to predict if air-capture technologies will in fact help stabilize greenhouse-gas concentrations. Certainly these technologies face technical, political and economic obstacles. Our rules do, however, allow us to strongly predict that stabilization is unlikely to be achieved, except in the very long term, without something like air capture. Such technologies should therefore receive much greater attention in energy innovation portfolios.

The climate-change example illustrates an important final point: technological fixes do not offer a path to moral absolution, but to technical resolution. Indeed, one of the key elements of a successful technological fix is that it helps to solve the problem while allowing people to maintain the diversity of values and interests that impede other paths to effective action. Recognizing when such opportunities for rapid progress are available should be a central part of innovation policy, and should guide investment choices.