Solar geoengineering steps out of science fiction: the issue is no longer just whether we can do it, but who should decide

Reflecting a small fraction of sunlight to temporarily curb global warming sounds like the premise of a sci-fi novel. Yet solar geoengineering is now the subject of research and institutional debate.

MIT Technology Review reported on a new roadmap designed to help decide whether and how to evaluate the potential deployment of these techniques. The point is not to argue that they should be used. It is to recognize that ignoring the issue does not make it any less real.

A global technology without global governance

The most difficult problem is political. Intervening in solar radiation would have effects that do not respect national borders. Who would have the right to authorize it? Who would be held responsible if a region believed it suffered negative consequences?

Today, there is no global authority with straightforward powers over such a decision.

Lowering temperatures does not mean solving the climate

Solar geoengineering does not eliminate the CO2 already accumulated and does not replace decarbonization. Under the most favorable assumptions, it could temporarily reduce a portion of the warming.

Treating it as an alternative to emissions cuts would therefore be a conceptual error even before a political one.

The risk of not knowing

One possible stance is to avoid research so as not to normalize the technology. But the opposite risk exists: finding ourselves in a severe climate crisis without knowing the effects, limits, and consequences of tools that some state might decide to use anyway.

Research can also serve to understand why a technology should not be deployed.

Governance must come before the emergency

Decisions made under pressure tend to be worse. Establishing rules now on experiments, transparency, data, and international cooperation could reduce the risk of future unilateral moves.

The climate future will not be purely technological

Geoengineering reveals a broader truth: some technologies become politically relevant long before they mature.

The most important question is not “can we do it?”. It is “what process would be legitimate to decide whether to do it?”. In the case of climate, this question could be even harder than the technology itself.