I saw Soylent Green tonight – odd that I've never seen it before. I thought I had; it may just be that everyone references it so often (and shouts the last lines so often) that it's become part of the culture. However, it's worth actually watching rather than just assuming , as I did, that you have watched it. The Pastorale scene  is quite as moving as critics said it was and a good half of the forecasts seem to have come true. (Possibly this is due to Harry Harrison, the writer of the seed idea for the film, a story called Make Room, Make Room, rather than the Hollywood script writers).
In the miss column, we have to admit that the future has not been full of Eames furniture, Eero Saarinen chairs and acrylic hangings. Pity, because they are quite nice. The strange and venemous-looking foxtail-based ten-legged furry spidery decoration never came to pass either, for which I am truly thankful. Young women provided as part of the furniture of a furnished luxury apartment – well, I think that's close enough to true to count.
The oddest thing in the 'hit' column is hearing the characters come out with a brief buzzword-bingo explanation of Global Warming, and why it's a Bad Thing. It's odd because the film was released in 1973 and if you read conservative columns written in 2006 and 2007 attempting to refute Al Gore's various scenarios, there's one thing they always say. They always say, "We're not falling for this Global Warming crap. Why, in the seventies, so-called climate scientists were predicting a New Ice Age. The idiots knew nothing then and know nothing now. Ha ha ha." Actually, they sound more stilted and hysterical than that, but that's roughly what they say.
If you read a column in the future that says scientists in the seventies predicted an Ice Age, kidnap the columnist and force them to watch Soylent Green, with their eyes propped open like in A Clockwork Orange, so that they can see what people really thought in 1973.
Edited to Add: My lawyer says I can't advocate kidnapping people even if they are stupid, so don't. Instead, when some idiot tells you that scientists in the seventies predicted an Ice Age, not Global Warming, send them this article. It's called, "Was an imminent Ice Age predicted in the '70's? No." I think that title about covers it. You can send them a copy of Soylent Green as well if you like.
But watch Soylent Green anyway. Even if you don't like the message, you'll probably like the chairs.
 Google tells me that the scenes of the world before overpopulation are accompanied by extracts from Tchaikovsky's Pathetique and Edvard Greig's Peer Gynt suite as well as extracts from Beethoven's Pastorale.