I'd referred to Peter Freuchen's Book of the Seven Seas to see if any of the events in Vikings had some versimilitude.  (Sort of.  Check the comments.)

But before returning the book to the library (you'll see its resting place, two shelves below the S-1, left end) I flipped to a couple of other chapters, and turned up additional quaint and forgotten lore.

Here's a passage from page 44.  Keep in mind, this book dates to 1957, at a time when anthropogenic carbon dioxide accumulation was esoterica from the seminar room.
One, which many scientists think is going on now and could accelerate in the not too distant future, is the almost complete liquidation of the last ice age.  A lot of the earth's water is tied up in glaciers, enough that even the melting of a substantial part would cause the oceans to rise about 100 feet.  If it all turned to water -- a very remote possibility -- it has been estimated that the sea level might rise as much as 500 or 600 feet.
Alternatively, though, the Ice Age could return, and the sea level would fall.  Three paragraphs at page 46 summarize.
With the great ocean extending its warm waters nearer to the poles and the refrigerating effects of huge ice masses gone, almost all the world would have the equable climate we associate now with the tropics.  Fruits and vegetables would grow in soil which now has only tundra.  It takes a large land mass to create the extreme changes of temperature we know in the temperate zone, and there would be no more land masses big enough to maintain the sort of weather we now have.

On the other hand, a new ice age would cover with glaciers much of the territory on which people live, and the rest would have to take lessons from the Eskimos on getting along with cold.  Caribou would return to the shores of the Mediterranean, where relics of primitive man show that these animals once thrived in an earlier ice age.

Neither of these glacial extremes is altogether fanciful.  In fact, both have happened four times in the last million years or so, in the Pleistocene age.  While most scientists believe that the earth is in a period of melting glaciers, and that this must go much further before another ice age descends, there is no certainty.
That's the extremely long run.  Starting at page 284 is a discussion of work by Swedish oceanographer Otto Pettersson, who proposes an 1800 year cycle of tidal magnitudes, influenced by the combined gravitational pulls of Moon and Sun.

At the margin, are time and tide beyond the power of our Industrial Age fuels to add or to detract?

No comments: