This song mourns the destruction of the environment in a modernized society. Oil catastrophies, radioactive waste, and overpopulation… we even Almost Lost Detroit.

In his biography Divided Soul, Marvin said:

When we don’t follow [Jesus'] example and turn to exploitation and greed, we destroy ourselves. That’s what ‘Mercy Mercy Me’ is about.

It was recorded in 1971, when the public’s awareness of environmentalism was at an all-time high. Imagine how mortified Gaye would have been if he had seen what was going to happen to the environment during the next 40 years …