The canopy theory posits that a blanket of water vapor separated the water under the sky “from the water above it” (Genesis 1:7) until the time of the Flood. This theory is used to account for everything from the water necessary for a global flood to the greenhouse effect necessary for human longevity. But does this theory correspond to reality?
First, the death knell to the canopy theory is that the “waters above the skies” and the expanse holding them back are found in the biblical text after Noah’s Flood just as they were before it (e.g., Psalm 148:4–6).
Furthermore, to misinterpret Scripture is to miss its meaning. When Scripture asks, “Who can tip over the water jars of the heavens when the dust becomes hard and the clods of earth stick together?” (Job 38:37–38), we do violence to the text by positing an ill-conceived “canister” theory. A “canister” theory, like a canopy theory, simply does not correspond to reality.
Finally, as aptly noted in some young-earth creationist literature, a blanket of water vapor prior to the Flood would have made the surface of the earth “intolerably hot, so a vapor canopy could not have been a significant source of the flood waters.”
and you waters above the skies.
Let them praise the name of the Lord,
for he commanded and they were created.
He set them in place for ever and ever;
he gave a decree that will never pass away.