The Bible says that Noah left the ark and got drunk (Genesis 9:21). It's hardly a fitting ending to a historical tale of faith and righteousness. It's hard to say what happened here, but there are various theories.
One theory is that Noah was just a victim of science. Assuming that the water canopy measured forty feet or more of potential rainfall, the surface atmospheric pressure before the Flood would be 2.18 pounds per square inch. This increases the partial pressure of carbon dioxide by a multiple of 2.18. As a result, the rate of fermentation of grapes slowed down. Before the Flood, wine took a long time to ferment because of the doubled partial pressure of carbon dioxide. After the canopy condensed, the rate of fermentation significantly increased. This hypothesis supposes Noah was simply caught off guard by the uncharacteristically high alcohol content in his drink.
It's a fact that drunkenness occurs much more rapidly at lower atmospheric pressures. One theory is that Noah was used to an atmospheric pressure of 2.18. So, when he drank wine under the new post-Flood atmosphere, he unintentionally got drunk. God never punished Noah for drunkenness, and the Bible doesn't say anything about him ever getting drunk again.
Look in the Book
In the Bible, God does not often shy away from confronting even his most devoted followers when they sin. Yet the account does not say that Noah sinned when he became drunk. In ancient times, wine consisted of one part grape juice and three parts water. It's possible that Noah's watered-down grape juice was more fermented than he realized because of the change in the atmospheric pressure.