What happens when north goes south?

This is hoped to be a discussion that will, just for a while, break out of the carbonist view of climate change. With luck it will involve a lot a guesswork without constant queries about where in the sacred literature the peer-reviewed reference to every half-baked thought is to be found. There are no peer-reviewed articles, or if there are, fine, we will quote them, if we ever heard of them and if useful. For I am a scientist and I have the authority to pronounced that it will be so. If, that is, you accept the very dubious proposition that geologists, even when considering geology, should be properly considered full science shamans with authorised command of the eternal verities and royal charters to see into the future.

I have myself been at this strange geology thing, on-and-off for 38 years now, and on some of my invoices to companies I even wrote that and they paid. But that length of time on your ticket says "mere beginner" to every sort of rock type, and they then set out to make a monkey of you. For rocks have a slow but very wicked sense of humour; ask Al Gore, he recently met some rather playful ice. Ice is formally a rock, see, and it really enjoys Al and Tim Flannery down here and particularly the economists like Richard Stern and Australia's Ross Garnaut - with lashing of politicians to top the cake. All sprinkled with journos and pop stars.

Anyway, here we go, folks.

Lots of folk from all over have laboured like huskies and got frostbite, drilling deep ice cores in the frozen lands, and I think we owe it to them to take their work seriously. Not to forget the huskies who hauled the drill-rods and suchlike about, if they did.

The combined deep ice drillholes of Antarctica can be treated as one drilling progam, "ours" in the widest sense of the word. I will fill in the technical details progressively, on this forum.

Basically, most of the holes, like Vostok, Dome C and Dome Fuji, were sited to get the longest possible cores, that is, cores that go back in time as far as possible, continental icecaps also being layer cakes, but in this case built up a tiny bit with each snowfall. So, oldest layers at the bottom, (mostly, and we will come to that qualifier) and youngest at the top.

You can tell where the ice is thickest from seismic studies - you whack a steel plate with a hammer a few times and you can get an echo off the Moho, the bottom of the earth's crust, if you are fit and have sensitive geophones and a good wave-stacking software program. I have done it, in my youth. No need for those huge trucks and explosions any more, unless are in Oz and you want to rattle out the windows in some old aunt's place in Norfolk or something. They also apparently use radar to determine the ice thickness, but I know nothing about that.

Anyway, all the deepest patches of Antarctica have now been drilled and the Holy Grail is not there. The Holy Grail is ice a million years old or older. They want to sing happy birthday to it, is what it is all about. But it has all gone. All the ice older than three quarters of a million years, plus maybe 30,000 years, all gone. Zip. Nothing. Nada. Niks.

But we should have a million years of ice older than 780,000 years, down there somewhere. We know that because the ice was having such a party back to 1.8 million years ago, that there was no room on the continent and bits of the grand icecake that was, got pushed off the edge of the table. Icebergs. They fell in the water around the table, the seas around Antarctica, that is, and of course all melted away. But the dust and the rocks they dragged with them off the table are still there on the sea floor, feeling forlorn. That was after the infamous party that went back 35 million yeas, but that is anther story, for another day.

So, marine seabed drilling around Antarctica says that extra million years of ice was there alright. As do moraines, lines of dumped rock high in the Antarctic mountains. A million years of missing ice, or several thousand metres of it, as you please. Not there, and nowhere to hide.

So what happened 780,000 years ago?

The magnetic poles flipped.

Do those flips pack enough energy to melt thousands of metres of packed-down snow? Seems so. When they had the worst magnetic storm on record, in the 1850's just the power that leaked into the telegraph lines was enough in some cases, to melt them, and in others to allow people to cheerfully keep sending Morse Code telegraphs for twenty minutes, with the power disconnected. That lot was estimated to be a swing of maybe 2,000 nanoTeslas, a unit of magnetic strength named after Nikolas Tesla's nanny. I think her name was Maud and he was very fond of her but don't quote me on that.

When the poles flip, the change is about 120,000 nanoTeslas, so it can get warmish. It's called magnetic reconnection and it is roughly why the sun is hot. The sun itself is an unimpressive 6,000 degrees C at the surface, so rumour has it, but is slightly warmer a bit up in its atmosphere as there, it gets up into the low millions of degrees C. Magnetic field lines getting tangled, that is, magnetic reconnection, is usually blamed.

So, the icecaps melt when the poles flip and if you do the sums, you will see that the coastal resorts will get dampish. The sea will most likely come up 50 to 60 metres.

Next time some greenhouse bore tries to horrify you and your nearest-and-dearest with a rise of 2 metres, or the gods forbid, maybe even 6 metres, wait quietly till he finishes and then pounce. We have the all-time blockbuster disaster movie plot here, all to ourselves. Don't tell Hollywood until you have the contracts all signed and sealed and placed in a tarred wicker basket.

Don't miss the next thrilling episode, in which, we will search for perched deltas and piles of stranded river rocks, scuba dive on the Arc de Triomphe and ride hump-backed whales around the Glasshouse Mountains. And wonder what else will be on special, on Magflip Day.

It's sort of like Groundhog Day, in that it repeats thousands of times over, but it's more fun, as they change most of the species each time.

Hooroo,

Peter.

This essay is in the public domain. Use or ignore to suit. PR.