While chatting with the crusty, 71-year-old palm-tree man who recently planted native sabals in my yard, I was taken with his views on human nature and the biosphere. Our species, he said, is magnificently inventive and imaginative but just shortsighted and selfish enough, woefully indifferent enough toward lower life forms, to destroy the biosphere that supports most life on Earth, including our own. It struck me that his observations sounded remarkably similar to the opening in Edward O. Wilson's latest book, Half-Earth: Our Planet's Fight for Life. The palm-tree man confessed he hadn't read the book but heard about it from a fellow patron of a local drinking establishment. And the book wasn't just about destroying the biosphere; it had a plan for saving it. That Wilson's ideas had circulated through a working-class pub would likely please him. One of the country's preeminent biologists, he doesn't write books for the cold steel shelves of academic libraries but for a broad, intellectually curious readership. His original insights integrating science and humanity and presented in accessible language have won him numerous awards, including two Pulitzer Prizes. Half-Earth is his 29th book, and the final in his trilogy on the Anthropocene, the current geological epoch. Precipitated by the headlong industrialization of the Western world, the Anthropocene is distinguished by the human imprint on the global environment, including oceanic and atmospheric pollution, climate change and the mass die-off of plants and animals, otherwise known as the Sixth Extinction. Neither crashing meteor nor supervolcanic eruptions but the "most destructive species in the history of life" has triggered this latest of the Earth's historic extinction events, and engineered its own demise. Wilson opens the book with a paragraph that effectively delineates the highest and lowest attributes of our species, hinting that hope lies in the former. From there he launches into a troubling prognosis for the Earth. In the lifespan of a child born today, human activity will realize the loss of 50 percent or more of known existing species, snuffing out in a few decades "millions of years of evolutionary glory." Wilson, who is 86, knows he has been fortunate to have seen much of this glory before it disappears. The Pensacola bay that fascinated him with its vibrant marine life when he was 7 years old, and steeled his enthusiasm for natural history, has since succumbed to industrial and wastewater pollution and turned biologically barren. The Southern piney woods that invited his first scientific studies were part of a 70-million-acre longleaf expanse ultimately logged down to 1,500 acres. By killing, polluting and trampling habitat, humans have accelerated the extinction rate to nearly a thousand times the normal, reversing the evolutionary process. Two books that significantly influenced Wilson growing up were the Boy Scout handbook and the King James Bible. You can see the rigor of the first and the gracefulness of the second in his tightly crafted prose. He also brandishes the latter when it serves a point, as when he cites Genesis to challenge evangelical claims that dominating the Earth fits with God's wishes: "Let the waters teem with countless living creatures, and let birds fly above the earth across the vault of heaven." Here, too, the Good Book suggests the essence of the biosphere, an abundance of species. "Biodiversity," Wilson writes, "forms a shield protecting each of the species that together compose it, ourselves included." Losing one species begins an unraveling that can reach a "tipping point at which the ecosystem collapses." Wilson insists we don't have to accept doom, that "humanity at its most noble" can forge a different outcome. His strategy for doing this is to set aside at least one-half of the Earth's surface in "inviolable natural reserves." This will gradually stop the extinction trend and allow new species to evolve. "Inviolable" means leaving nature "unharmed" and to its own devices. Conventional conservation has failed at this because it often settles for less than the unharmed standard. Most existing national "wild" lands — parks, forests and preserves — allow resource extraction and wildlife management, including killing "nuisance" grizzlies in Yellowstone and alligators in the Everglades. Harm within can also originate outside conservation areas, as in the case of water managers sending agricultural runoff into Everglades National Park. Unlike Wilson's Half-Earth plan, conservation also lacks a common goal, which clarifies purpose and rallies public support. Floridians will be skeptical about the political resolve to embrace Wilson's goal. The state's regressive leadership has recently mandated climate-change denial, flouted a voter directive to purchase protected land and authorized bear hunting in a region where a restored longleaf reserve has been created in the vision of Half-Earth. Wilson is nevertheless hopeful that the reserve, founded by the late MC Davis (who has been featured in this newspaper), is the start of something grander. He is similarly convinced that myopic leadership is on the wane (not all extinctions are bad), soon to be replaced by a new moral reasoning on the rise. He is seeing its manifestation in an amassing wave of green technology, which he regards as complementary to his plan. (I'm seeing a glimmer of it in my students; and look at the refreshing views of Pope Francis). Wilson's sense of the future cannot be easily dismissed. Over the years, we have learned a lot about the world and ourselves from him; and with Half-Earth, a book of vision and welcome optimism, he has yet more to teach us. A professor of environmental history at the University of Florida, Jack E. Davis is the author of "The Gulf: The Making of an American Sea," to be published in 2017.