there'samomentwhenyourealizethat"globalwarming"‘schanged.whatdoesthe1stSmeanby?

Question

there 's a moment when you realize that "global warming"‘s changed .
what does the 1st S mean by?

Answer 1

Your question should be "What does the 1st s mean?" or "What is meant by the 1st s?"
The first s which is in the phrase"there's" is short for "is" and the second one in " global warming'‘s" is short for 'has'.