CLAIM: Critics point out that rainbows have been around since precipitation occurred in the early Earth. However, this passage seems to imply that God created rainbows after the Flood. Which is true?
RESPONSE: This objection results from a fundamental misunderstanding of the text. Rainbows did not begin at the time of Noah; instead, God began to use the rainbow as a sign at this time. In the same way, while a wedding ring might sit in a shop for ten years, it becomes a symbol of commitment the day that it is exchanged with a spouse. Rainbows have existed for eons; however, they became a symbol of God’s loyalty only after the Flood. Moreover, similar to English, the Hebrew word for bow (as in “rainbow”) was the same word for bow (as in “bow and arrow”). In ancient Near Eastern culture, a bow (and arrow) had great significance. For instance, if the bow was pointed with its strings down, it was a sign of peace. This may have been why God picked this as a symbol for the people. He was communicating divine peace over the Earth.
 I am indebted to Dr. James Hoffmeier’s class on Old Testament from Trinity Evangelical Divinity School for this observation.