...And We Will Have Snow

Chapter 5-2: The World Dream

"The dream begins this way." The visual display withdraws from Sedna's presence, reveals her to be standing on a wind-blown rocky coast, from which it soars upward until it is a view of the whole Earth, and then withdraws farther still until it displays the Earth-Moon system, with the Sun blazing in the distance.

"There are two great reservoirs of energy that interact to create the climate of Earth, and enable its biosphere to develop and thrive.

"The greater, easy to observe and simple to understand, is the Sun, pouring a steady stream of energy into space." Here the visual input zooms toward the sun, its brilliance dimmed to display its vast corona, with the loops and whorls that testify to the tremendous electromagnetic currents that surge within it.

"A tiny fraction of that energy flows toward Earth, which intercepts, captures and re-emits it. It is this balanced interruption of the solar energy flow that energizes all life on the planet." As this is said the view swings around to focus on the image of Earth, now smaller, and zoom in on that until it looms large.

"A lesser but still massive reservoir is the rotational energy of Earth itself." Here Earth's rotation becomes apparent. "This too is simple when taken as a whole, far more complex when considered in detail, and even more so when its interaction with the solar energy is examined." The view swings around again until Earth and Sun are seen together. The emotional impact of these visuals is enhanced by peripheral signals, akin to a musical score but playing on the mind more subtly.

The scene now shifts to a close-up of Sedna, then draws back to reveal the figure of Karen standing next to her.

"The views you are seeing were produced by the WBI computer model, the most detailed model of Earth and its climatology ever developed, using data derived directly from the Q. Here with me is Karen, principal developer of the model, to tell you something of what it has revealed."

The view zooms in on Karen as she begins to speak, then swings away to display images of the things she talks about.

"If Earth were truly flat and still, as some ancients contended, then solar energy would simply warm the surface air, causing it to rise, cool, and fall again in regular patterns, like water boiling in a pan." Here a visual of this process is displayed.

"But Earth is round and turning, so the patterns are not so simple." The visual curls itself into a ball, and the ball starts to turn. The patterns begin to bend and twist under the influence of this motion, forming great swirls. The ball morphs into a view of Earth, and the swirls become cloud patterns.

"Forces similar to the ones that make these patterns of cloud and wind act on the oceans, making current patterns. Here we see just one example of how the model explains what is actually happening." The view zooms in on the North Pacific, animated by arrows showing ocean currents. The animation evolves as Karen goes on.

"Cold winds from the north draw heat and moisture out of warm surface water from the south. The now cooler water, stirred by the wind, draws more air into solution, making it heavier. For as long as the northern waters are free of ice the winds do this, and carry evaporated moisture south to drop over the cold continents as snow.

"Meanwhile the northern waters, cooled by evaporation and weighted with newly dissolved air, sink down to the seabed. There the same force that makes the north wind blow makes the deep water circle down toward the equator. Nudged along by Earth's rotation, the water circulates slowly, taking many years to carry the influence of events in the north to where they can affect the southern waters. Finally the cold deep waters begin to rise and mix with sun-warmed surface waters. This tempers their chill, making them belch into the air dissolved oxygen and carbon dioxide they can no longer hold, before they circulate north again."

As the visual rises out of the ocean and drifts over land, Sedna's voice picks up the narrative. "This cycle may continue until the snows are permanent and extensive, and deflect a significant amount of sunlight away from the planet, finally allowing the northernmost waters to stay frozen, cooling the planet and absorbing more carbon dioxide into the open oceans to the south." The view zooms out to reveal a planet different in ways both stark and subtle. Vast snow fields are apparent over much of the north, while coastlines look slightly wrong because they are reconfigured by the drop in sea levels that accompany the spreading snow.

Sedna's voice remains ethereal as the view backs away from Earth to again encompass Moon and Sun, and distant stars. "What we have seen only suggests the unexpected complexity of climate, impossible to anticipate in detail, however simple it might be to explain once it evolves.

"The Sun has its own internal complexity, but the resulting modulations of the energy flow intercepted by Earth remain small compared to its average output.

"Like the Sun, Earth continually leaks its own energy into space. Part of the internal complexity of both Earth and Sun derives from a third source, the gravitational influence of a large sphere of matter. There is also a continuous creation of dark matter, to which we now contribute."

There is a pause.