FELIX SALMON: The horrifying AAA debt-issuance chart. “Firstly, the amount of debt in the world is soaring. That’s a bad thing, because debt is much more systemically dangerous than equity. And secondly, the amount of triple-A debt in the world is soaring as well. Which is a worse thing, because triple-A debt is much more systemically dangerous than most other debt. . . . In a nutshell, triple-A debt is dangerous; there’s far too much of it; its growth seems out of control; and the triple-A problem has now become a sovereign-debt problem, in a world where sovereign-debt crises are the most damaging crises of all. . . . If sovereigns start being downgraded from triple-A status, debt is going to get a lot more expensive, and those rollovers — which cost very little in the current interest-rate environment — will really start to bite. And the invidious thing about debt is that it doesn’t go away. Deleveraging is painful, and is often accompanied by inflation or default. And the more debt you have to start with, the more painful deleveraging is going to be. Prepare yourselves.”

But see this, which alas does not undercut the warning above.