"Life may be unique to Earth. Even if single-celled organisms can readily evolve in conditions that exist on millions or billions of other planets, we have no actual evidence that complex, multi-cellular life exists anywhere else in the vastness of space. Bacteria appeared on our planet roughly 3.7 billion years ago; by 2 billion years ago, the tree of life was branching into what would become a stunning web of creatures, huge and tiny. Plants, animals, and fungi proliferated, formed relationships, and produced ecosystems. The result was a planet full of life, and one whose atmosphere, temperature, chemical composition, and weather are all largely shaped by the side effects of the strategies that organisms use to thrive. However, in a matter of mere centuries, we humans are unraveling the web of life and triggering a mass extinction event that is likely to impact virtually all species on the Earth, and to destabilize the fundamental planetary systems upon which we too depend. Mass extinctions have happened before. The web of life is, paradoxically, both resilient and fragile. On five previous occasions (most recently the Cretaceous-Tertiary extinction 65 million years ago) our world lost up to 95 percent of its species. The current wave of extinctions that’s being triggered by humans is, so far, not on the same scale, but it is proceeding far more rapidly than previous ones. We humans represent a new kind of threat to the rest of life: our development of language, tool-making, and fire-spreading rendered us hyper-effective hunters and foragers. Tens of thousands of years ago, we were already reshaping landscapes and impacting wildlife. Our ability to expand our own habitat has generated unwanted results: some prey animals were hunted to extinction, and in a process of competitive exclusion, humans caused many local extirpations by appropriating the resources of habitats for themselves. These unintended effects then impacted humans themselves, often by compromising their food supply. Therefore, over time, humans who stayed in any given ecosystem long enough to learn its limits embraced cultural traditions to moderate their demands on it. However, since the start of the European conquest of most of the rest of the world, and especially since society’s rapid adoption of fossil fuels starting around 1800, human impact on the biosphere has accelerated at a breathtaking pace. Expanding human populations and associated land use changes, industrial agriculture, industrial forestry, industrial-scale fishing, proliferation of toxic chemicals, and climate change are decimating native species of plants and animals around the world. According to some estimates, populations of many non-domesticated species have declined, on average, by 70 percent, and the pace of species extinctions has quickened to 100 or more times the usual or “background” rate. What will the world come to look like if these trends continue? In one scenario, Earth will have become fully domesticated in a century or two, so that humans and machines control planetary systems (including climate patterns, ocean currents, the water cycle, and the carbon cycle). In this possible case, very little of wild nature will be left. In the far more likely scenario, the unraveling of the web of life and the destabilization of planetary systems will lead to the collapse not just of biodiversity but civilization as well. Is it too late to save biodiversity and the living Earth? … I’ll argue that only a collective effort to put wild nature at the center of our priorities will prevent its devastation and the possible disappearance of our own species, among countless others."