I attended a class a few months ago at my church on Creation Science, and the teacher had some interesting notes about the biblical case for a global, rather than local, flood of Noah. I've culled, with his permission, some of those notes and present them here. They're probably at least in large part taken from Answers In Genesis, but I'm no connoisseur of Creation Science, so I thought these were pretty good.
The Bible Speaks of the Physical History of the Earth in Terms of Three Worlds
• The Ancient World – Before the Flood
-2 Peter 2:5 [God] did not spare the ancient world, but preserved Noah, a preacher of righteousness, with seven others, when He brought a flood upon the world of the ungodly;
– 2 Peter 3:5-6 For when they maintain this, it escapes their notice that by the word of God the heavens existed long ago and the earth was formed out of water and by water, through which the world at that time was destroyed, being flooded with water.
• The Present World
–2 Peter 3:7 But by His word the present heavens and earth are being reserved for fire, kept for the day of judgment and destruction of ungodly men.
• The New World
–2 Peter 3:13 But according to His promise we are looking for new heavens and a new earth, in which righteousness dwells.
The water prevailed more and more upon the earth, so that all the high mountains everywhere under the heavens were covered. 20 The water prevailed fifteen cubits higher, and the mountains were covered. 21 All flesh that moved on the earth perished, birds and cattle and beasts and every swarming thing that swarms upon the earth, and all mankind; 22 of all that was on the dry land, all in whose nostrils was the breath of the spirit of life, died. 23 Thus He blotted out every living thing that was upon the face of the land, from man to animals to creeping things and to birds of the sky, and they were blotted out from the earth; and only Noah was left, together with those that were with him in the ark.
Some Questions Based on the Text, if the Flood Were Local
If God wanted to teach a global Flood, how could He make it more obvious?
• Why did Noah have to build the Ark? He could have walked to the other side of the mountains.
• Why did God send every kind of animal to the ark to escape extinction? There would have been other animals on the other side of the mountains.
• Why was the ark large enough to hold all kinds of land vertebrate animals existed? If only Mesopotamian animals were aboard, the ark could have been much smaller.
• Why were birds onboard? They could have flown to a nearby mountain range.
• How could the waters rise to 15 cubits (8 m) about the mountains (Gen. 7:20)? Water seeks its own level. It couldn’t have risen to cover the local mountains while leaving the rest of the world
untouched. Nor would a local flood take a whole year to subside.
• People who did not live in the vicinity would not have been affected and would have escaped God’s judgment on sin. But then what did Christ mean when He likened the judgment of all men to the judgment of “all” men in Noah’s day (Mt. 24:37–39; 2 Pet. 3:3–7). A partial judgment in Noah’s day would have meant a partial judgment to come.
• God would have repeatedly broken His promise (Gen. 9:11–16) never to send such a flood again, because there have been many local floods since then.
• The Bible uses special words for Noah’s flood (Heb. mabbûl; Gr. kataklusmos). Compare to the words used to describe ordinary localised floods (Heb. sheteph, nahar, nachal, zaram; Gr.