Risks are like that.
They don't appear to be connected, but, like piano keys controlled by an unseen paper roll, they produce music when coordinated, and cacophony when not. Striking a single key produces a single tone. Striking several blindly means dissonance. But striking a group of keys in a coordinated way produces a chord. The biggest problem facing us, however, is how to measure all these risks in terms of their potential likelihood, their possible consequences, their correlations and the public s perception of them.