Urgency and the Ice Cap:
This posting is not for everybody. If you have read this far and are a true believer, then you have better things to do than read it. You need to be talking to people. If you still harbor doubts, then skip this because it will do nothing to persuade you that a large gene pool is inherently unstable, and it will do nothing to increase my credibility. On the other hand, if you understand the argument but feel there is plenty of time for things to sort themselves out, then maybe this will get you moving.
Not only does this not add any further evidence, but it is quite off topic. It is, on the other hand, very timely, so I offer it now while there is still some question about the immediate future of the climate. Right now, think about how easy it would be to get word around. You certainly have friends you meet regularly, and a larger number you can reach by telephone, text messaging, email, My Space or by snail mail. If you spread the word to ten a day, and everyone who heard about it did the same, the world would know within a couple of weeks. A major catastrophe would take away all but the friends you see, and even some of them, and you would have other urgent things to discuss. There are many potential catastrophes, but this one could be breathing down our necks. Let me describe the nightmare.
Word has been spread that the Arctic Ocean could become ice free this very summer. Cooler heads, (Quirin Schliermeier, The Long Summer Begins, NATURE vol. 454, no. 7202 July 17, 2008 page 266) give it about an even chance that the amount of ice cover lost this year will exceed the amount lost last year, which was a major record breaker. If it happens, it will happen before mid September, the next 4 weeks. When that happens, there is a very good chance things will be different. What will they be like?
According to Thomas Friedman, (The Iceman Cometh, NEW YORK times, reported in the Tampa Tribune, August 6, 2008), over the past 200,000 years, there was an ice age that lasted 70,000 years, a warm period of 15,000 years, an ice age of 103,297 years duration and the present warm period, which has lasted 11,703 years. In other words something like 27,000 years out of the last 200,000 have been anything but ice age. It does not take much courage to say that a return of an ice age is a real possibility.
How fast would it come? Evidence from the Greenland glacier (Jergen Peder Steffensen and others, High-Resolution Greenland Ice Core Data Show Abrupt Climate Change Happens in Few Years, SCIENCE vol. 321 no. 5889, August 1, 2008 page 680) and sediment from a German lake (Quick start to a cold spell, NATURE vol. 454, no. 7205 August 7, 2008 page 670 reviewing Nature Geosci.doi:10.1028/ngeo263 2008) agree that it can happen pretty fast. And less formal evidence is even more impressive. You have heard of mammoths frozen in the ice with unwilted flowers in their stomachs and the Grasshopper Glacier where there were grasshoppers that would fall off the face of the glacier as it melted. We should always have known that the term “glacial speed” meaning slow was a misnomer. Glaciers can appear in hours.
But before we worry, there has to be a plausible mechanism.
Imagine a horizontal line segment going from A to B. Measure its length and draw two arcs above it each centered on an end and each of radius equal to the original distance AB. They will intersect at a point C. Connect A, B and C and you have an equilateral triangle. Take the mid point of the line BC and call it D. Connect D with A. There are now two triangles sharing a side. One side of each equals a side of the other because they are sides of the ABC triangle. BD equals CD because we chose the center point, so we have 3 sides equal in the two triangles so the angles will be equal. The line DA thus splits the angle BAC in half. The angle DAB is 30 degrees. Now if sunlight is coming from straight over head it will put a certain amount of energy every minute into the line AB. But if the sun is at 30 degrees above the horizon so that it is perpendicular to the line CB, only the light that enters the segment DB will actually strike line AB. Exactly half of the energy strikes AB as if the sun were straight overhead.
Now when the sun is its farthest north in the sky, it is only a little less than 30 degrees above the horizon at the North Pole. It is putting in energy at a rate that is just half of what it puts into the Tropic of Cancer at noon. But at the Tropic of Cancer, the sun is below the horizon for twelve hours, while at the North Pole, it is there for 24 hours. Worse, even during daylight at the Topic of Cancer, the sun is not always higher than 30 degrees. The amount of heat arriving at the North Pole is not then twice as much as arriving at the Tropic of Cancer. But it is still much more than what is arriving at the Tropic of Cancer.
Ordinarily, the incoming energy, mostly in the form of visible light, is reflected back into space because the poles are sheathed in ice. But take away the arctic ice pack and that energy gets absorbed. Ice will reflect about 90% of incoming energy, while water will absorb about 90%. Land is somewhere in between. There is no land at the North Pole, but at the tropics there is a substantial amount of land. So the amount of energy actually being absorbed at the North Pole becomes pretty close to twice what is being absorbed in the tropics and well over twice what is absorbed the world over.
If sunlight around the world on average is able to lift the surface temperature from the about 460 degrees below zero Fahrenheit of the cold of space to a livable 70above, doubling that energy could make things approach something over 500 degrees. Of course the North Pole could never get there. The Arctic Ocean would boil first. But things could get very hot. The tundra might dry out and burn, releasing more carbon dioxide than all known fossil fuels combined. If you are not a greenhouse gas believer now, you might become one. Swamp gas, methane, under the permafrost might escape and burn … conflagration of biblical magnitude … polar bears incinerated in their tracks … narwhales boiling in their own blubber … blah, blah … blah.
I hate to sound irreverent. But I am. So what? We’ll survive. We’ll survive any climate change. There are places that could use more water and places that could survive with less. There are places that would be nicer if they were warmer and places that would be nicer if they were cooler. And all of those places have one thing in common. People live there. People will manage. Besides, this is all theory. It has never been seen to happen. Contrast that with the falling birth rate which has happened and which could make us extinct, and don’t worry too much on this one.
Perhaps you have noticed something. I promised you and ice age, the return of Gog and Magog the Frost Giants and all that, and so far it is just getting hotter and hotter. Or maybe you are way ahead of me.
So the hot Arctic Ocean gives off a lot of water vapor, which must go in two directions, up and south. It wants to get to the South Pole. As it goes up, it becomes rain, then snow, then ice carried by vertical winds upward and held aloft on the fringes of space (very cold, you remember) until this fiercest of all earthly storms drops it as giant hail stones at an unthinkably low temperature. Take stratospheric air and put it under pressure and it will warm up. Take ice and put it under pressure and the temperature will not change much. That hail will be very cold. The storm could last a long time.
You know something about those mammoths and grasshoppers? Flowers and grasshoppers aren’t found on ice. Glaciers come in the summer. We always knew that, didn’t we?
Yes, it might take out our civilization. The trouble is we don’t know how to prepare for it. The most obvious thing to do is to prepare libraries that contain all the treasures of our arts, our sciences, our technology and an apology for having depleted all the handy sources of energy, and place those libraries so that no hundred mile square lacks one. Then when the descendants of our survivors crawl out of their caves long hence, they will be able to benefit from what we now know.
And what single treasure will be the most important to include? In time they can work out nuclear physics and reinvent Shakespeare and the King James Version. The one thing that will mean the most to them is the secret that will let their civilization survive more than 10 generations. Everything else will follow.
The most important thing in that library would be the contents of this web site.
But maybe not the silly bits.
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