What would our earth be like without clouds? For one thing, we would be deprived of a great deal of beauty. Clouds add pleasing variety to our skies, and sometimes at sunrises and sunsets they form fantastically beautiful tapestries in the air.
But this is merely the least thing that clouds do for mankind. Of far more importance is the fact that clouds bring rain, the vital source of moisture for nearly all of life.
Without clouds, the earth might be as water-rich as it is today, but it would all be in the oceans. The continents would be vast deserts without life of any sort. Clouds are the great transfer mechanism by which moisture is distributed to soften the land and clothe it with life.
But this still does not exhaust the catalog of the value of clouds. They also form a protective blanket around the earth. The sun daily bombards our world with the equivalent of about 3 ½ million kilowatt-hours of radiant energy, per square mile of surface. But clouds absorb some of the energy, and help shield us from damaging ultraviolet short-wave radiation. They also bounce some of sun’s radiation back into space. Less than half of the incoming energy actually reaches the earth’s surface.
Most of the energy which does reach Earth is stored in the oceans, which cover more than 85 percent of the surface of the globe. This stored energy is utilized in evaporating water vapor from the oceans, to form clouds. This process can convert more that 5,000 tons of water into atmospheric water vapor per hour, from each square mile of ocean. (Water: Miracle of Nature, by Thomson King, MacMillan Co., N.Y., 1953, p. 63.) That’s a lot of water! But it takes a lot to fuel our cloud systems. Water vapor, which is invisible, is not yet cloud. In order to become visible and form real clouds, these molecules must gather into tiny droplets of liquid water. (Did we say “tiny?” It would take 8 million of these droplets to make one fair-sized raindrop!)
Even such minuscule droplets cannot form, however, unless even smaller motes of dust or other solid particles are present for the liquid to condense upon. But what with dust storms and forest fires and industrial air pollution, etc., there is no shortage of particulates. It has been estimated that a single puff of cigarette smoke liberates about 4 billion particles! (ibid, p. 64)
These myriads of tiny droplets easily remain airborne, and can travel for thousands of miles, waiting for the opportunity to blend with each other into drops large enough to fall to earth as rain. This happens when the cloud becomes “saturated.” That is, the total load of water becomes more than the air can hold. Cold air can not accommodate nearly as much moisture as can warm air, so when a cold weather front meets or overruns a warm front, part of the latter’s water freight falls as precipitation.
Whether the precipitation will fall as rain or snow, or even hail, depends upon the temperature of the air. Snow forms when the temperature is below freezing, and winds are gentle. Hail forms when rain meets violent updrafts, which carry the drops up to freezing levels before letting them fall again. The hail stones pick up more moisture as they fall, but they can be caught up in more updrafts and refrozen. This can happen repeatedly, and the stones grow in size each time. It is not unknown for such stones to be the size of oranges when they finally reach the ground!
Clouds could not make their vital contributions to life on earth if it were not for the unique qualities of water. As one observer put it, “Water, with its trick of making itself invisible, and reappearing as either a liquid or a solid (snow), and its ability to absorb or release immense quantities of heat, gives us our weather.” (ibid, p. 78)
Thank God for our weather! If we think about it, it is God whom we should thank, for nothing and no one else could have created water with so many marvelous qualities. How foolish to imagine for one moment that such a vital substance “just happened!” Or to think that it “just happened” that the proportion of oceans to land mass is just right to balance the world’s heat storage requirements. Or that it “just happened” that water can become a vapor lighter than air, and thus become the source of clouds.
Every time we see a cloud in the sky, was are witnessing one of God’s blessings upon man. And we should take note that God does this for all, whether good or bad. As Jesus Christ said, “ For he makes his sun to rise on the evil and the good, and sends rain on the just and the unjust.” (Matthew 5:45)
But while God distributes the blessings of nature without partiality, it is not so with His favor. As the Bible says, “Your blessing be on your people.” (Psalm 3:8) And again, “For you will bless the righteous. …you will surround him with favor as with a shield.” (Psalm 5:12) But of wicked persons, God says: “… I watch over them for evil, and not for good…” (Jeremiah 44:27)
It does, after all, matter a great deal that God watches over His creation. “The friendship of Yahweh [that is, God] is with those who fear him. He will show them his covenant.” (Psalm 25:14)
(All Scripture is quoted from the World English Bible translation.)