The deleveraging vortex
Shipping rates for transporting raw materials to the great manufacturing economies of the world, as measured by the Baltic Exchange Dry Index, have halved over the past month - and have fallen 75% since mid-May.
This index is normally seen as a leading indicator of global economic activity.
In recent years it's been buoyed by China's voracious appetite for the world's natural resources, especially iron ore.
There may be one or two exceptional factors depressing shipping rates, such as a decision by China (which may turn out to be temporary) to consume from its vast stockpile of iron ore rather than bring in more.
But the fall in rates is redolent of a global economy on the turn, in a pretty sharp negative direction.
It's the backdrop to yesterday's forecast by the IMF that the world's economy will grow at 3% in 2009 - which is on the cusp of what it regards as a global recession.
And it's the context for the co-ordinated cuts in interest rates by central banks, from China, to Europe to North America - which extended overnight to rate cuts by South Korea, Taiwan and Hong Kong.
The emergency action by the authorities to reverse the direction of the global economic supertanker away from a seriously impoverishing economic downturn also includes the lending of taxpayer's money to banks on a mindboggling scale.
This is absolutely essential, if banks aren't going to dramatically reduce what they lend to households and businesses and to ensure that at least some of the reduction in official rates is passed on to customers.
But the world's banks are becoming seriously dependent on incremental funding from central banks, and special additional liquidity provided by finance ministries, to make up for the seizing up of money markets - which in turn stems from the fear that grips managers of vast pools of cash (typically our pensions and long-term savings) and makes them wary of lending money to any bank where there's even the faintest smell of trouble ahead.
The money managers are switching their investments into government bonds and official national debt in its various forms, on the assumption that we as taxpayers are always good for our debts - although the recent behaviour of the Icelandic government in apparently failing to honour its deposit insurance guarantee to Icesave customers makes that a slightly more courageous assumption than it was.
What's happening, therefore, is that money managers are lending to governments like ours, and those governments are then recycling that money to the banks.
The perfect illustration of this is the £250bn guarantee announced yesterday by HM Treasury for short and medium-turn debt issued by our banks - that should allow them (phew!) to refinance their debts as they fall due in the next two or three years.
There's quite a big question - for later - about how on earth we wean the so-called commercial banks off their addiction to borrowing from the state.
And if the addiction can't be broken, there'll surely be big implications for how banks are permitted to behave (should a taxpayer-supported institution be paying any of its employees 800 times average earnings, which a few that are now utterly dependent on taxpayer support have been doing?).
But for now the pressing issue is how we can pull the global economy out of the deleveraging vortex, how we can crush the devastating phenomenon of banks collectively atoning for their past sin of lending too much by lending too little.
No single government, not even that of the US - as Hank Paulson, the US Treasury Secretary, conceded last night - can contain the destructive power of deleveraging, of the de-facto lending strike, on its own.
It may require global collective action by governments on a scale we've never seen before.
You only have to look at the implosion of Iceland's ludicrously oversized financial economy to recognise that even the British government's £400bn package of support for UK banks is a drop in vast and stormy global ocean.
Today the Icelandic Financial Supervisory Authority is taking control of the country's largest bank, Kaupthing.
It's not as big as Lehman, but it's connected to lots of other international financial institutions and businesses, and it has $73bn of assets.
Some of its overseas assets were dumped on the market yesterday. If there's a fire sale of the rest, the pain would spread way beyond this small and storm-battered nation.