There was no single day when the last tree disappeared. No alarm. No countdown. Just a quiet, irreversible silence. The Last Forest imagines the world that follows — a planet stripped of every forest, every woodland, every last naturally growing tree. Drawing on decades of ecological, climate, and hydrological science, this book traces the cascading consequences continent by continent: rivers that flood without warning then run dry, soils that blow away in dust storms, wildlife extinctions that ripple through entire food webs, and human societies forced to replace with costly technology the invisible services forests once provided for free. From the vanished Amazon and Congo to the bare slopes of the Himalayas and the silent eucalyptus woodlands of Australia, the story unfolds as both a rigorous examination of how forests truly shape Earth’s systems and a carefully reasoned vision of what remains when they are gone. This is not science fiction. Many of the early symptoms — intensified floods, shrinking wildlife, degraded soils, shifting rainfall — are already visible. The Last Forest is a warning written in the language of what we still stand to lose, and a reminder that the most important systems on Earth are often the quietest.