Sing that chorus with me, won't you? Eerie, isn't it? I doubt he had read the very sparse theoretical science on climate change that was around in the 60's. What we see here is purely artistic intuition.
Perhaps you don't accept the reality of global warming. I don't really care to argue with you about it. It's too late to do anything about it, anyway.
Poke fun all you like. They laughed at Tiny Tim, too, and all he ever wanted to do was spread joy and wonder. Me, I'm going to dream along with Tiny Tim. I'm going to dream that he had the last laugh. I'm going to dream of a peaceful world of playful fishies.