Sadly, I can’t provide a synopsis to do it justice. He argues that humans have a responsibility to rise above a mere animalistic existence and make conscious choices for the benefit of all creation. When animals act like beasts nothing is amiss. But the irony is that they limit themselves by nature (e.g. predation) whereas we as humans are prone to exploiting nature and can only limit ourselves by conscious choice. Nature is in need of redemption in the sense of being rescued from an undesirable state and restored to wholeness.
Now, if we ask the question whether nature needs to be redeemed, we must answer: Yes, urgently, more urgently today than ever before! Humans, as a result of their failings, degrade the natural world, and nature is at peril owing to human cultures on Earth. There is something perverse about an ethic, held by the dominant class of Homo sapiens, that regards the welfare of only one of several million species as an object and beneficiary of duty. We lust. We are proud. We are selfish. These escalating human desires, coupled in this century with more power than ever before to transform the earth, have put nature in travail. In this sense, the fall of nature, far from being archaic, is among the most imminent threats; nature is at more peril today than at any time in the last two and one-half billion years. We may face the end of nature, unless human cultures can be redeemed.
Several billion years worth of creative toil, several million species of teeming life, have been handed over to the care of this late-coming species in which mind has flowered and morals have emerged. Yet this sole moral species has not yet been able to do anything less self interested than count all the products of an evolutionary ecosystem as resources for our consumption. That does not sound like trusteeship; that sounds like corruption, a fall from human nobility. Insatiable overconsumption is cancerous, if not psychotic.