To be honest, I don't remember the Charlton Heston movie too well, but my sense is that this book is only losely an inspiration for Soylent Green. It follows the dismal story of a detective trying to chase down a mob-boss's murderer in an awful future world where everything is scarce except horrible people.

Writing in 1966, Harrison tells the story of a 1999 where there isn't enough power, not enough water, not enough food, not enough room. People are crammed next to each other in a hot and horrible New York City. Everything is rationed, nothing works well, and even the rich seem paupers by today's standards.

"For this the Army gave me a fine fifteen grand education as an aviation mechanic," he said, patting the stove. "Finest investment they ever made." The stove had started life as a gas burner, which he had adapted for tank gas when they had closed off the gas mains, then had installed an electric heating element when the supplies of tank gas had run out. By the time the electric supplies became too erratic--and expensive to cook with, he had installed a pressure tank with a variable jet that would burn any inflammable liquid. It had worked satisfactorily for a number of years, consuming kerosene, methanol, acetone, and a number of other fuels, balking only slightly at aviation gas while sending out a yard-long streamer of flame that had scorched the wall just before he could adjust it. His final adaptation had been the simplest -- and the most depressing. He had cut a hole in the back of the oven and run a chimney outdoors through another hole hammered through the brick wall. When a solid-fuel fire was built on the rack inside the oven, an opening in the insulation above it let the heat through the front ring."

The book was written two years before Paul Ehrlich's The Population Bomb when everybody thought the world was quickly going to be overwhelmed with people. Resources were running out and a sad socialism was the inevitable end of the glorious human race. Seems like they miscalculated.

...but it does make for an interesting story. Our hero, the detective Andy Rosch works for a police department that usually doesn't bother with anything other than crowd control. Somebody important to the important mob boss's gets murdered and all of a sudden the captain of Rosch's precinct wants a lot of time put into the case. All Rosch finds is a mistress and an air conditioned apartment (shocking luxury!) that is paid up through the end of the month.

"Well, it's not very important," she laughed, "don't look so sad." She leaned forward and gave him a quick warm kiss on the mouth. Before he could react she had turned away and gone down the hall. The shorts were very short, and very, very round. As the door clicked behind him he realized suddenly that he was quite happy. The air was wonderfully cool.

Understandably, Rosch starts putting a lot of time into the case.

If there's any point to the story, it's that the squalor and depredation of the masses eventually reach everyone. Or just that the future sucks:

"Do you know what meat flakes are? I heard all about it on TV today, not that I wanted to but how could I turn the damn thing off? A big sales pitch program on taming the wilds in Florida. Some wilds, they should hear about that in Miami Beach. They stopped trying to drain all the swamps and are doing all kinds of fancy things with them instead. Snail ranches -- how do you like that? Raising the giant West African snail, three quarters of a pound of meat in every shell. Plucked cut, dehydrated, radiated, packed and sealed and sent to the starving peasants here in the frigid North. Meat flakes. What do you think of that?"