Some of the conditions described in the Revelation could match up to global cooling.
But more to the point of the op, Revelation has different sections, the first, the letters to the churches, deals with things that are or were about to be.
The second deal with future events.
When the Revelation was written the destruction of 70 AD had already happened.
Here it is good to remember that there has not been just one day of the Lord where something of monumental importance happens.
Many people don’t know that the late date for Revelation is from a single ambiguous statement by Ireneaus in about AD 160. So we have to study what Revelation itself says about the dating. In my article I list about a dozen reasons why the book was written before AD 70:
The evidence of when Revelation was written points to a date under Nero around 68 AD, not a date under Emperor Domition. The proponents of a late date hold to the testimony of one second-hand witness who also said that Jesus lived into his fifties. Hardly reliable. Other church fathers only quoted him.
In my extensive research, I have come to the conclusion that Revelation speaks to historical events. From a surface review, from early in the book to late, it specifies numerous times in the clearest of language that the events were soon to come. So, either John through the revelation given by Jesus didn’t know when the events would happen, purposely misled the recipients of the letter, or he knew exactly when they would occur and can be held to his word. I hold to the latter.
To the subject of this blog, I would have to agree that John lived to see the “coming of Christ”, and event that he wrote about in the last chapter of his gospel. The other gospel writers had long sections regarding the Olivet Discourse, John omits it. I believe that Revelation is that discourse in much further detail. The elements match extremely closely.
I also agree with others that we’ll know more clearly upon leaving this earth. There’s no reason to debate heavily. Yet, I would agree with the premise that has been made that a fulfilled prophesy is much more powerful than an unfulfilled one. I find joy in knowing that what was promised by Daniel, Jesus, and John actually occurred in the manner and in the timeframe as it specified would occur: within one generation (40 years) from Jesus’ ministry.