Global economy: Is a major risk being overlooked?

It is now crucial to analyse everything that could trigger a marked deterioration in the global economy. The following come easily to mind : Excessive debt, if interest rates rose sharply; A real estate bubble in some countries; Protectionism; Recruitment difficulties; A sharp rise in the oil price; Another emerging country crisis caused by major capital outflows from these countries; A crisis related to the illiquidity of some investment funds. These risks are well known, and they can be monitored and measured. But are other hidden, less visible risks that are as significant being overlooked ? Are we aware of all the risks that, if they materialised, could worsen the global economy markedly ?