Genesis 1:6

A firmament. Or, “an expanse.” The work of the second creation day consisted in the formation of the firmament. The great mass of primeval “waters” was divided into two separate bodies. The “waters which were above the firmament” (v. 7) are generally considered by commentators to be water vapor. The climatic conditions of the originally perfect earth were different from those existing today.

Explorations carried out in the far north have proved that luxurious tropical forests once covered those land areas that are now buried under eternal ice and snow. It is generally conceded that pleasant climatic conditions prevailed during this earth’s early history. Unknown were the extremes of cold and heat that can make life unpleasant in most regions of the world and virtually impossible in some.