The last ice age ended about 10,000 years ago, and the planet entered a long, stable period of mostly warm, mostly wet conditions. Scientists call this geologic epoch the Holocene. Our entire history of civilization fits within it. All our revolutions in farming, city building and industry happen in the Holocene. But the Holocene is ending now, and it’s ending because of us. Human impact, most notably climate change, is altering how the planet functions.

In response, scientists see a new epoch in Earth’s evolution rising, which they call the Anthropocene. But creating a long-term sustainable version of civilization in the Anthropocene raises a new and profound set of questions that remain hidden to us when we stay fixated on saving the Earth.

What, for example is nature? From the biosphere’s perspective, a city is fundamentally no different from a forest. Both are the result of life’s endless evolutionary experiments. And forests, like grasslands, insects and oxygen-producing microbes, were once a evolutionary innovation. In that sense we, and our project of civilization, are not a plague on the planet. We are just what the biosphere is doing now. The question then becomes what changes must we make to still be “what it’s doing” many millenniums from now?

A civilization of our scale will always have effects on the biosphere. To imagine otherwise is to ignore the laws of planets we’ve so recently discovered (laws of physics, chemistry and biology). It also ignores the biosphere’s own history in which pervasive, “successful” species always have an impact. Our mission cannot be to eliminate impact, which would be impossible short of a human die-off, but to have the right kind of reduced impact.

We must come into some as-yet-unimagined cooperative relationship with the biosphere in which all boats rise. This means understanding what makes the biosphere — with us still in it — more robust, innovative and resilient. But it is unlikely that every species on Earth now will make that journey with us. It might well turn out that microscopic phytoplankton matter far more to this kind of healthy biosphere than our beloved polar bears. We are going to face hard choices with deep ethical consequences. Pretending we can just extend the Holocene in perpetuity without those consequences may lead to a greater disaster than facing them with insight.

This recognition — that in the long term the Earth will abide without us — does not absolve us from the need for urgent action. It is not an excuse for climate denial or ecological hooliganism. It also does not mean we are free to just impose suffering on Earth’s other creatures. Instead, it’s an acknowledgment of the true scale of our planetary responsibilities. It means we must become the agent for something the Earth has not seen before — a biosphere that is also awake to itself and can act for its future with both compassion and wisdom.