Wednesday, June 13, 2018

2941. Earth Will Survive. We May Not.

By Adam Frank, The New York Times, June 12, 2018
Stock market

In 1968, the astronaut William Anders looked out from his moon-circling Apollo 8 capsule and saw the mottled blue Earth emerging over the gray lunar horizon. It was the first time anyone had seen an Earthrise, and the picture he snapped became iconic.

In it, our world appears lonely and fragile set against the blackness of space. Fifty years later, Mr. Anders’s picture remains a visual shorthand for the pressing need to save the planet from our worst behavior. But what if we’ve misunderstood the real meaning of that image? What does it even mean to “save” the Earth?

If Mr. Anders’s spaceship had crested the moon 55 million years earlier, he would have found a sweltering jungle planet so warm it was almost entirely devoid of ice and snow. On a visit around 700 million years ago, he would have stared at a “snowball” Earth almost entirely covered in miles-thick layers of ice. And if he touched down on our planet three billion years ago, his first experience, should he take off his flight helmet, would have been a quick death by asphyxiation. That Earth, already home to life, had air but no oxygen.

All these versions of the Earth have one thing in common: They were all profoundly shaped by life. It was life acting through microbes that helped set off some of Earth’s “snowball” phases. It was life in the form of blue-green bacteria that first gave Earth its oxygen atmosphere. Ever since the Russian geochemist Vladimir Vernadsky coined the term “biosphere,” scientists have come to see life as an equal player in the drama of Earth’s history.

The biosphere is a cosmic power in its own right. It’s a planetary force that channels vast energies flowing from the sun and transforms them into ceaseless rounds of blind evolutionary innovation. That power gives Earth and its biosphere a long-term resilience we must now fully imagine if we are to come to terms with the climate change we are driving.

We speak of “saving” the Earth as if it were a little bunny in need of help. We show images of gaunt polar bears on melting ice floes to elicit guilt and environmental action. But those images and stories blind us to the reality of this remarkable moment in Earth’s history.

Our planet does not need our saving. The biosphere has endured cataclysms far worse than us — and after millions of years thrived again. Even the Earth’s five fearsome mass extinctions became opportunities for the biosphere’s creativity, driving new rounds of evolutionary experiments. That, after all, is how we big-brained mammals ended up dominating the Earth rather than our dinosaur predecessors. As the great biologist Lynn Margulis once put it, “Gaia is a tough bitch.” In the long term, the biosphere will handle pretty much anything we throw at it, including climate change.

What Earth’s history does make clear, however, is that if we don’t take the right kind of action soon the biosphere will simply move on without us, creating new versions of itself in the changing climate we’re generating now. So we must be honest. The problem is not saving the Earth or life writ large, but saving our cherished civilization. From that perspective the nature of our choices changes significantly.

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.

Adam Frank, an astrophysics professor at the University of Rochester, is the author of “Light of the Stars: Alien Worlds and the Fate of the Earth.”

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