Borders may soon be redrawn by the weather

A drafting exercise conducted by an academic group in international law has produced a model treaty clause for frontiers that follow a physical feature capable of moving: a watershed, a channel, an ice divide, a shoreline. Under the model, the border would be defined as the feature itself rather than as a set of coordinates, and would therefore migrate as the feature does.

The idea is not novel. Rivers have been moving borders for as long as there have been rivers and borders, and the law already contains centuries of doctrine about what happens when a channel shifts gradually versus abruptly. What is new is the pace, and the fact that several of the features in question are melting rather than meandering.

Alpine states have already had to adjust a frontier because the ice divide defining it retreated, an event handled quietly, technically and without drama by surveyors who would prefer to keep it that way. The model clause would generalise that approach, on the theory that a rule agreed in advance is cheaper than a negotiation conducted after a glacier has made its own arrangements.

“A border that moves is not a weaker border,” a spokesperson for the drafting group would argue. “It is a border that has been told the truth. The alternative is a line on a map that is correct in the archive and wrong on the mountain, which we have found tends to be discovered by somebody with livestock.”

The maritime version is considerably harder. Sea level rise threatens the baselines from which territorial waters and economic zones are measured, and several small island states have pushed hard for those baselines to be fixed permanently regardless of what the coast does. Here the model runs the other way: nobody wants a moving border when the movement only goes one direction.

The political objection is the real one. A frontier that is understood to be negotiable with the weather is a frontier that somebody will eventually propose renegotiating for other reasons, and the drafting group concedes that the clause would be safest in places where the two states involved already get on. That is a small set, and it is not the set with the urgent problems.

The exercise is academic, unadopted and unlikely to be signed by anyone. But glaciers are retreating, coastlines are moving, and the maps currently in use were drawn on the assumption that the landscape would hold still, which it has stopped doing.