Admittedly, a giant volcanic eruption is not an everyday event, but then again neither is pushing the Earth's climate system into a new dynamic state.
There is chaos in Europe as the continent spanning plume of ash from volcano (I can't even spell it) shuts down the airspace of one country after another. The mess reaches far beyond the tens of thousands of trapped travelers. If the volcano continues to erupt for a long enough time shipping of perishable goods, military resupply and a host of other domains could be severely affected.
The eruption renews our respect for the awesome amounts of energy planet's have at their disposal. It also has me thinking about sensitivities inherent to the "systems" supporting the modern global village. Everyday a web of air traffic links the world's economies driving the hyperactive, just-in-time flow of goods and services. The effect of the volcano's plume shows one boundary condition on the operation of the air transport system. And while the eruption and the plume will pass, this experience throws a stark light on the sensitivity of all the complex systems keeping us in a "normal" that is really just half a century old.
Given the very real possibility that we have pushed the planet onto a changing climate trajectory how sensitive are these systems we depend on. What are the boundary conditions for their smooth operation? If, for example, rainfall patterns change a little will it be easy worldwide systems of agricultural production and distribution to adapt? What if they change a lot?
We know that we are changing climate. We do not know how dramatic the changes will be. In light of that uncertainty do we understand our own flexibility?