It's all the more incredible given that Soylent Green was explicitly about climate change and associated crop failure, set in 2022. In the dialogue between Sol and is called the "greenhouse effect," the older term for what we now call climate change. From Stanley R. Greenberg's script of August 10, 1972:

SOL: How can anything survive in a climate like this -- a heat wave all year long --

SOL AND THORN (together): The Greenhouse Effect -- everything's burning up.

I must rewatch it (for hire on YouTube) and see if that made it into the final cut.