Ending the Sixth Mass Extinction

Life on Earth is made of and made possible by an inconceivably intricate web of relationships among myriad and diverse species. Each species has been shaped by evolution and woven into an ornate ecological tapestry across eons that dwarf the totality of human history. Beyond the grasp of human intellectual powers, the complexity of the biosphere is perhaps best comprehended by its beauty – beauty visible both in its mossy, roaring, shimmering presence and in its abstract, geometric and mathematical elegance. 

The global web of ecosystems is resilient and can withstand a certain amount of shock and abuse. Some extinction, some disturbance, won’t destabilize the whole. However, as more threads are broken, the fabric risks tearing apart. It took nature billions of years to weave this life-creating tapestry and human activity over the last 200 years is wearing it thin. What ecologists call the “Sixth Mass Extinction” is the definitive sign that holes are beginning to form in the tapestry of life. Humanity destroys its home at its own peril.

The Problem

  1. Practical: The greatest threat facing humanity is the ongoing species extinction crisis, referred to by scientists as the Sixth Mass Extinction.1 The extinction crisis is the unraveling of humanity’s biological life support system.
  2. Moral: The greatest moral imperative facing humanity is to end the extinction crisis – all human and non-human life hangs in the balance. The ongoing Sixth Mass Extinction is the moral equivalent of genocide against the natural world and civilizational self-destruction.

The Background

Extinction is normal. Species regularly go extinct as a consequence of competition, natural selection, and environmental change. Mass extinction is not normal. In a mass extinction event, species go extinct much faster than what is historically normal. There have been five other mass extinction events in geological history.2 Each has been caused by a cataclysmic disturbance to Earth’s systems – a giant meteor impact, a chain of volcanoes erupting for centuries, etc. The Sixth Mass Extinction is different. This time, the mass die off of species on Earth is being caused by the voluntary actions of a single species. This time mass extinction is a choice.

The Cause

The Sixth Mass Extinction is fundamentally an issue of carrying capacity. Humans require resources to survive, so each additional individual exacts a resource toll on the environment. Humans, like all other species, require habitats that supply water, food, physical space, shelter, and a variety of other goods (the human footprint is far larger than the human carbon footprint).3 Further, humans share a planet with countless other species that also need habitats and resources. Therefore, the human carrying capacity of the Earth must not be set at the absolute physical limits of the Earth itself, but at a point of balance which allows other species to survive and flourish. The ongoing Sixth Mass Extinction is incontrovertible proof we are already far out of balance.

The chief cause of the Sixth Mass Extinction is explosive, exponential human population growth that has far exceeded Earth’s human carrying capacity. The world population in the year 1800 was under one billion. Today it is eight billion.4 Simultaneously, technological advancements have enabled many humans to consume far more resources per capita. Indeed, to suggest technology is the solution to humanity’s environmental woes is to ignore the overwhelming historical trend of technological progress enabling additional resource consumption, not reducing it. Technology will not provide a magic solution to the extinction crisis. The only solution is for humans to make the choice to adopt an ethics of limits.

The Solution

The locus of action for solving complex, global problems is in and among nations. Every nation on Earth must choose to do its part to end the extinction crisis by gradually shrinking its population. Citizens of every nation have the right and the duty to collectively choose to adopt a national ethic of limits to population growth and implement both family planning and immigration policies to realize these ethical principles.5

America is home to more than 1,300 threatened or endangered animal species. That number has steadily increased for decades, despite billions of taxpayer dollars — and billions more in private spending by environmentalists — devoted toward conservation.

Karen Shragg



In all the perturbations of earth systems that mark the onset of the Anthropocene, human population growth is at the heart of the problem. All credible estimates of the earth’s human carrying capacity clearly show that we are already beyond long-term sustainability. Only through increased intentionality with regard to human population growth can we avoid catastrophic failure of the support system for human well-being as well as the well-being of the web of life in general.

Carnegie Museum of Natural History

Recommended Viewing

  1. The Year Earth Changed
  2. What are Animals Thinking and Feeling?
  3. 8 Billion Angels – A Global Documentary