Claim 2 - The 'Vapour Canopy'

This theory was proposed by several proponents of Creation in order to explain simultaneously the Biblical flood, and the enormous ages of humans recorded before the flood. For example, the book of Genesis states that Adam, the first man, lived 930 years (Genesis 5:5). Many of his descendants lived over 900 years (Genesis 5:6 et. seq.). According to the book of Genesis, God then decided that man was living for too long, so decided to reduce his age to 120 years (Genesis 6). This happened during the life of Noah, and was achieved around the time of the great flood concerning which, according to the book of Genesis, God stated "I will wipe mankind, whom I have created, from the face of the earth - men and animals, and creatures that move along the ground, and birds of the air - for I am grieved that I have made them." (Genesis 6:7)

According to the Genesis account, the flood then killed almost all life on Earth, except those animals who dwelled in the water, and those few who were saved along with Noah in the Ark.

Some creationists put forward the idea of a 'vapour canopy', created at the time the Earth was formed, which hung several miles above the Earth and shielded the Earth from the Sun's harmful Ultraviolet rays. They claim that this protective layer would produce a warm, tropical climate on Earth, and would also allow the humans who lived there to live for vastly longer periods of time, perhaps a factor of twenty over what they could have expected to be a reasonable life span of 45-50 years without modern healthcare.

First of all I plan to investigate the plausibility of a 'vapour canopy', in the sense described by Creationists. Then I will investigate the claims that such a canopy could have both caused the flood (by its falling to Earth) and allowed the elongated lives of those who lived under its protective shield.

Note that throughout this article, I'm really considering a "mist" canpoy. I assume that this is what the creationists really mean. Clearly a vapour canopy is a ridiculous idea - the energy required to keep a substantial amount of water in gaseous form up in the atmosphere would be ridiculous. Adam and Eve would have been cooked very quickly indeed! It would have been like living in a steam cooker!

How much water would be required?

A first investigation is the determination of the required water content of such a canopy. The book of Genesis states that the flood waters rose so high that they covered the peaks of the highest mountains to a depth of twenty feet (Genesis 7:20). Mount Everest is the highest mountain on Earth, and its height is 8850 metres. If we ignore the extra 20 feet, and then calculate the amount of water required to cover the earth to this depth we obtain a value of 4.5 billion cubic kilometres. (asuming the Earth's radius to be a constant at 6360 kilometres.) Actually this is a slight underestimate, but I'll take the lower value.

This site tells us that the total volume of water on the Earth including all the oceans and the icecaps is approximately 326 million cubic miles, or approximately 820 million cubic kilometres. This is a factor of 5 lower than the volume of water required to cause the biblical flood.

How much rain would this cause

Let us investigate the rainfall rate that this amount of water would require. Assuming that it fell uniformly (which will give us the minimum possible value for the maximum rainfall rate) we can take the Biblical account and work out what the rainfall rate, in metres per hour, must have been to cause such a flood. The Bible states (Genesis 7:12) that the rains lasted for 40 days and 40 nights, or 960 hours. Now we know that the depth of water must have been 8850 metres, so this equates to a rainfall rate of 9.2 metres per hour, or 15 centimetres per minute. For comparison, the highest rainfall rate ever measured on planet Earth was 187cm in one day for Cilaos, Le Reunion in March 1952. (See this page.) The flood rainfall is a factor of 118 times higher than this!

Of course, this is not a disproof, by any means. Genesis also talks of water coming from underground; "all the springs of the great deep burst forth," (Genesis 7:11). We could investigate if any substantial amount of water could be stored underground, as this tends to suggest.

Could this water be stored underground?

The Genesis myth tells of water springing forth from the deep. Some creationists have argued that this might be able to explain the volume of water required. In addition, they argue that this might also explain where all the water went after the flood - a problem which we have yet to address. So how much water could be stored in the Earth's crust?

This site tells us that the deepest borehole ever drilled into the Earth's crust was 12km. The temperature of the bottom of the well was 190 degrees celsius, significantly above the boiling point of water. If water existed at this depth then it would simply evaporate and work its way up through fissures in the rock, bubbling out at the surface or condensing below the surface. Either way, water could not exist at 12km. Another borehole in Germany was 10km deep, with a base temperature of 118 degrees celsius. This is still too hot, but not by such a staggering amount. We could estimate that the temperature would drop sufficiently far below boiling point at around 9 kilometres depth.

Now remember that the amount of water required was a depth of 8.85 kilometres. If we were to store this in the Earth's crust then we would require 98.3% of the Earth's crust to be made of water. That simply isn't the case. Therefore we are forced to abandon this theory. (Furthermore, the average crust thickness under the oceans, which occupy over 70 percent of this planet's surface area, is only 5 kilometres, further reducing the possible quantity of water that existed under the Earth.)

Note - I should really take into account the pressure here, which would increase the boiling point of water beneath the Earth's surface. I have no accurate idea what level of effect this would have, but it certainly wouldn't be enough to make this theory plausible.

Could such a large amount of water have existed in the atmosphere?

We are forced to conclude that, presuming the Biblical account is being argued, the waters must have almost all been stored in the atmosphere. Were it not for this then we simply could not store that volume of water in the Earth's crust, or even anywhere near that volume. We would simply have found it by now.

So how could such a canopy exist? Could it simply form part of our atmosphere? Well to work this out we can consult science. We know that the atmosphere has a density distribution which follows an exponential law. That is to say that the density of the atmosphere drops off by a certain factor for a constant increase in height. The scale length for this drop off is a few kilometres. If the layer existed in liquid water form then its density would be much higher than that of the surrounding air at any height, and therefore it would immediately fall back down. However, could it exist as water vapour?

The density of steam is approximately 1/1000th that of liquid water, so even compressing the vapour as much as possible this layer must have stretched almost 10,000 kilometres into space. Now at a height of 10,000 kilometres the Earth's gravitational field is almost seven times weaker than it is at the surface, so it is not at all obvious that the Earth could hold on to this layer of vapour. I'll do the calculations some time.

However, we can still reasonably easily calculate the pressure that such a layer of water must have exerted, assuming that the majority of it is going to be lying at a height where its density is considerably higher than that of the atmosphere surrounding it (which is a perfectly valid assumption in this case - water vapour is about half as dense as air at sea level, but is ten times more dense at a height of 40 kilometres, because of the exponentially dropping atmospheric density. Remember our vapour layer is 10,000km thick, so the majority of it is therefore in this regime.

The scale depth for pressure increases in the ocean is approximately ten metres. This means that for every ten metres of depth the pressure increases by one atmosphere (100,000 pascals). Therefore, under ten kilometres of water, the pressure would reach around 1,000 atmospheres or 100 million pascals. This is the same as the pressure at the bottom of the deepest ocean trenches where so far humans have been unable to travel. In fact, we have been unable to manufacture machines out of thick reinforced steel able to withstand such pressures. All living creatures under a water canopy consisting of ten kilometres of water (except for the simplest of micro-organisms) would be crushed to death immediately.

Would a 'vapour canopy' truly protect us from ageing?

So what would the world have been like under such a canopy, with the exception of the immediate prospect of being crushed to death? If one considers the equivalent height of water contained in the atmosphere above our heads right now, it is only a few centimetres, dropping to a few millimetres in dry, high altitude sites. With almost ten kilometres of water above our heads we could expect quite a change.

Well Creationists claim that this large layer of water vapour would protect us from harmful ultraviolet rays from the sun. They are absolutely correct. In fact, as I show below, it would protect us from practically all of the Sun's radiation, but that's another argument. However, the concept of advanced ages is an interesting one, and must be addressed scientifically.

Is there any evidence that human beings were designed to live for longer than about 50-60 years? Well human females have approximately enough eggs to last into their fifties. They never generate any new ones. After this age, humans have essentially fulfilled their usefulness in a biological sense , and the concept of humans having children well into their hundreds of years is clearly quite absurd. One should also consider the development of teeth. Before the advent of good dental care, most people would have lost their teeth in early age, just as animals do. However, the concept of someone living to the age of 900 even with today's dental care doesn't bear thinking about. Without dental care they would probably have been chewing on gums for 95 percent of their lives!

And what of the protection from UV radiation? Well that's all well and good, but it doesn't help humans fight disease, nor does it help us protect ourselves from wild animals and accidents. In fact, it won't help protect us from cancer much because many elements in the Earth are radioactive on their own, and can cause cancer without the Sun's rays. Interestingly, after the flood, and presumably without the protective vapour canopy, Noah lived for a further 350 years (Genesis 9:28). His sons lived into the 400s, too. If the UV layer had gone then how did this happen? Furthermore, if they had been living behind a UV protection layer of such vastness then their skins would not have developed any protection from the sun's rays - they would have been whiter than white. When that layer was removed they would all have caught skin cancer alarmingly quickly.

What would the Earth really be like

Astronomers hate water vapour - it stops them from observing the stars. Those of us who have looked through a fish tank know that water distorts light - what we see is blurred. And that's only a small amount of water. With ten kilometres of the stuff hanging over our heads we would not be able to see the stars at all. In fact we can investigate what we would be able to see. This site gives us the attenuation coefficient for a clear lake as 0.2 m^-1. Let's assume that this water from the formation of the Earth is super-pure and therefore we can take a coefficient of 0.1 m^-1. How much light from the sun would reach Earth through this blanket?

The calculation is actually remarkably simple. Light attenuation is another exponential decay problem, the mathematics of which is simple high-school stuff. We can see straightforwardly that the fraction of light reaching the surface of the Earth after travelling through ten kilometres of water would be exp(-0.1 * height) is approximately one part in 10 ^ 260. Effectively this means that the Earth would have been perpetually dark. You know what happens when a dark storm cloud consisting of water vapour just a few hundred metres in height goes overhead? The skies are dark. Well here we're trying to see what would happen if a cloud of vapour 10,000 kilometres in height went overhead. The entire Earth would be plunged into darkness.


The theory of a vapour canopy is so utterly wrong that it fails at nearly every possible hurdle. Just the simplistic scientific tests to which I have subjected it show that it fails catastrophically on even the most simple points of reason. The concept is undeniably false, and should be disregarded in its entirety.


If anyone is interested in the details of the calculations on this web page then please write to me and I will do my best to explain them.

Is this a fair representation? If not then drop me an email. Address below.

This page maintained by Colin Frayn. Email
Last Update : 2nd December, 2005