"Endurance" would have sufficed. "Let your nays be nays and yays be yays." The skyscraper does not represent endurance at all, true or otherwise. The oldest is slightly over a single century in age and there are things in this world and out that have endured far more than a redwood.
Your language is undoubtedly the chief reason I enjoy your poetry. I STILL have a problem with your lack of faith in punctuation. I know, I know you desire to write a poem so elegantly constructed that punctuation is unnecessary. That the sentences flow so flawlessly from one to the other that periods, commas and the like are superfluous. In all of your poetry there are moments where I must halt, back track and start again because I have plowed through a sentence ending unmarked. My reading skills could use some work as well, but I still wish you'd deign to use a little of the stuff for the ignorant who read your work. It wouldn't hurt the poem while you were struggling toward your inevitable, artistic end.
The pace of everything you write is a joy to read (another reason to wish you'd not dismiss the punctuation). Your use of enjambment is superb. I rather struggle with it in my writing even though it is a necessary characteristic of any poem that dares to be many hundreds of lines long. Often the the new line starting in the middle of a sentence needs the reader to momentarily readjust the pacing to aid it in "fitting in". There is no such difficulty in your poetry. Your enjambment flows from one line to the next with no pause to reconcile the two lines. This is likely accomplished on your part through nothing more than instinct, but as I do not have such a sense and must "earn" my enjambment, I consider yours to be a "talent" or "skill" and envy it.
The theme is an old one, but I have never had a problem with revisiting "old" themes. Nothing is new under... It's all in how we present it. My favorite of this genre is this- "65 million years from now no one will know what we did...nor care." I choose 65 million years very deliberately. It is when the dinosaurs disappeared from the Earth. Your theme is a good theme and not merely because I agree with it wholeheartedly.
I am one of those mortals that feels the first line of any written work is special. Like a teacher of mine once told me- "You must be able to jump up and down on it." Being four lines long, your beginning is a little cumbersome, but as it is matched in a literal sense with the closer it is my opinion they both do their jobs well.
Pretty good eh? Using the filled in questions I was able to tell you almost everything important I wanted to say about the poem. Save one I missed.
The poem was very good and I like it.
wesley

After reading Wesley comment I can't imagine what to add
accept to say I like the reference to the twin towers (only assuming) and the redwood tree.

Usually I'm not a fan of rhyme schemes, but your use of the A,B ryhme is superb. The vocabulary you use is amazing (not one banal word used) and there are beautiful, clear and striking images.

The tone reminds me of 'Ode On A Distant Prospect Of Eton College' by Thomas Gray.

"With its brethren side to side
a forest of steel formed skyline
testimony to man's misplaced pride
( as if Man would suffer no decline )"

This particular stanza reminds me of 'A Ramble through St. James'' Park by Rochester.

This is a very sophisicated poem and you've nailed the rhyme scheme!

If you haven't read either of those two poems I mentioned, please do, they will inspire you, and are a good example of what you can do with a good rhyme scheme:)!