Real Climate Records

By “ACHENAR MAJOR.”

At various periods in the past extensive areas of the globe have been subjected to glacial conditions, and many of these areas enjoy to-day a temperature, subtropical, or even tropical climate.

Two of these glacial periods are noteworthy, namely, one which occurred about the time of man’s appearance, and has left very definite records in the Northern Hemisphere: and one which occurred just prior to the formation of the extensive coal fields of the Southern

Hemisphere, and affected South America, Africa as far north as the Sahara, Australia, and India.

These great variations in climate in the past—and the above mentioned periods are merely two selected from a list which possibly includes minor glaciations to some extent—are corroborated by the changes which are reflected in Antarctica, where coal seams, fossil trees, &c., indicate that at onetime the rigorous conditions now obtaining were preceded by a temperate climate. Various theories have been elaborated at times, embodying such suggestions as a shifting of the poles of the earth, disposition of the land and sea areas, greater height of the land masses, variation in the amount of carbon-dioxide in the atmosphere, distance of the earth from the sun, &c.

None of these theories enjoys general acceptance. This great variation in climatic conditions must have played a very important effect in the distribution of animal and vegetable life.

It has been suggested that the old palaeozooic or earliest corals, termed Rugosa, which were replaced by the modern stony corals, were influenced by such climatic changes.

It is interesting to note, in this connection, that, in all probability the Barrier Reef once extended much further southwards than at present.

There are to be found masses of dead coral, where no living coral now occurs, or where the

latter is at the present day but sparsely developed.

This would suggest that, in all probability, there has been a cooling of the sea water, resulting from essentially climatic change, or arising from some cause which has produced an alteration in the currents in the southern or affected area.

Certain it is that climate is changing continuously.