The Future of Our Own Earth

Otago Witness, Issue 1916, 10 August 1888, Page 32

The Future of Our Own Earth

regarding her life as that of an orb whose special purpose in creation (to use convenient though inexact words) is to support life, animal and vegetable, upon her surface, we have to direct our attention to various circumstances on which the earth's life, so viewed, depends. Our earth might cease to be an abode fit for the higher forms (at any rate) of life, through the unresisted action of these forces which tend to denudation. The action of rain, wind, snow, storm, rivers in their courses to the sea, and seas beating continually on their shores, all the activities in fact, which are included in what geologists call sub-aerial denudation, would, if unresisted, bring the whole of the earth's surface to what would literally be a dead level. Sir John Herschel once remarked, and later researches have but strengthened the validity of his conclusion, that since the land and water first existed forces energetic enough have been at work long enough to have removed every trace of dry land and leave our earth a water-covered world. And though this would not absolutely mean the death of the earth, yet certainly it would be the death of the world as we view it — as certainly as the cessation of the functional activities of the human body mean death, though lower forms of life continue in the dead body. But again, the earth's life would disappear if another process went on in sufficient degree which it itself would seem to resist the influence of the levelling foroes just considered. There can be no doubt that the qnantity of water outside the solid surface of the earth (considered alike where it is under as where it is above water); is continually though slowly diminishing. Geologists estimate that already one-third of the waters belonging to the earth have passed beneath the earth's 3rust. The process is going on all the time. Not all the water raised from the sea by the sun's action, carried over continents, falling in rain, and forming rivers, is returned by the rivers to the sea. Not all the water which having fallen on suitable parts of the earth's surface has found its way beneath the crust, is returned by springs to the surface. Year tey year, century by century, water is absti'acted from the seas, and though in the thousands of years over which men formerly looked forward (even as they then looked backwards over no longer periods) the sea-level would not be appreciably affected, yet in the millions of years doubtless belonging to the earth's future (since such periods certainly belong to her past), every trace of water would be removed if the process continued unchecked. Suppose for example that in a single year the sea-level sank through but about the thickness of a sheet of stout paper, in 100 years through rather more than an inch, in 1000 years through a foot. That would be nothing. A few feet difference in the sealevel, in a few thousands of years, would be a change not worth considering, if the earth's future had to be regarded as limited to but those few thousands of years. But a foot in 1000 years would mean