Something New Around the Sun: The Case for an Environmental History that Spans the Cosmos

Scroll this

What is environmental history? 

Many of the leading lights of our field have tried to answer that question. Donald Hughes called it the study of the “mutual relations of humans and nature through time.” To William Cronon, it’s a kind of history that identifies “the role of non-human nature” in human affairs. For John McNeill and Erin Mauldin, it’s “the study of the relationship between human societies and the rest of nature on which they depended.”

But what is nature, and where does it end? 

For many people, nature is wilderness: the ostensibly untouched parts of the biosphere. Of course, environmental historians – led by Cronon – long ago established that this view of nature is a colonial fantasy, made possible by the eviction of Indigenous nations from what are now natural parks. 

Nature, in any case, also has a much broader definition. It can be synonymous with the Earth, including the nonliving Earth. This is the definition that seems to square with the subjects of environmental history, which include everything from earthquakes to ocean currents. Nature appears to end at the upper atmosphere, where air seems to give way to nothingness, and so environmental history does, too. One way of describing the field is therefore a reimagining of humanity’s past as part of the dynamic planet on which it unfolded.

It’s a way of understanding history that, to me, recalls one of the most important photographs in the history of space exploration. 

It was February, 1990. A robotic probe named Voyager 1 hurtled towards interstellar space at over 60,000 kilometers per hour. The planetary scientist Carl Sagan lobbied for the probe to take a final photograph of the solar system, a “family portrait” that included the Earth. When the scientists and engineers in charge of the probe agreed, the resulting picture was, in a sense, profoundly unimpressive. 

the "pale blue dot" photograph; a streak of white light across a dark sky
Earth: A “Pale Blue Dot.” A remastered version of the original photograph. NASA, 1990.

But “look again,” as Sagan put it, and it hits you. Notice the “pale blue dot,” a pixel just to the right of center? That’s Earth. Viewed from more than six billion kilometers away, our world is revealed for what it really is: a “lonely speck in the great enveloping cosmic dark.” It’s a dot that challenges our pretensions, and compels us to revisit our history. It helps us feel the absurdity of the violence that some of us inflict on others because they – to paraphrase Sagan – claim a privileged place in a universe that actually wouldn’t notice their absence. 

It also seems to expose what we might call the planetary boundedness of our history. Humanity is so intimately connected to the Earth that we’re indistinguishable from it when viewed from afar. Cities and clouds, fields and forests, roads and rivers: looking from the outskirts of the solar system, all dissolve into a single blue dot. 

The pale blue dot therefore provides a powerful argument for the importance of environmental history. And at first glance, it justifies both the limits of the field and the character of its political significance. Just think: in the picture, all of nature amounts to a single pixel when viewed from afar. It’s hard to imagine a better argument for its precariousness, for the importance of preserving it. And it seems obvious that the pixel captures the entirety of environmental history. 

But look at the picture a third time. Far from isolated, the “mote” that is the Earth is, as Sagan wrote, “suspended on a sunbeam.” Without the sunbeam – without the Sun – it wouldn’t exist. Earth is just detritus left over from the Sun’s formation. Today, many of its forces and flows, of matter and energy, are powered by the Sun. 

And the Sun is a dynamic place in its own right. Its immense magnetic fields, looping out from its incandescent surface, rotate at different speeds around its core. They interact, twisting and turning until they snap in colossal explosions that blanket the Earth in charged particles. The Sun’s “activity” waxes and wanes in cycles, as does the strength and scope of the flow of particles – the “solar wind” – blowing across the solar system. For reasons still poorly understood, the Sun’s total output – its irradiance – meanwhile fluctuates across decades and centuries. Environments on Earth therefore continually respond to changes in what we can only call environments on the Sun.

Although outer space looks black to our eyes, which evolved to let us navigate environments on Earth, it surges with energy and matter. These flows mean that asteroids, comets, moons, and planets – including Earth – are all connected, like islands in the ocean that are bound together by currents in the air and water. More connected, in fact, for in space the islands are always moving. The big islands (the planets) tug on each other with their gravity but are too distant to touch. The small islands (the asteroids and comets), by contrast, follow paths that cause them collide with islands of all sizes. 

a space photograph of the Indian Ocean; ripples, eddies, and flows
Oceans on Earth have a lot in common with the ocean of the cosmos. Diverse and dynamic environments are in constant motion, and continually interact. “View of the Indian Ocean taken during ISS Expedition 9.” NASA.

In a new book, Ripples on the Cosmic Ocean, I therefore reimagine the solar system as a mosaic of environments – some dense, others diffuse, but all dynamic and interacting. I argue that the division we’ve perceived between Earth and the rest of the solar system is, in part, an illusion. To me, nature spans the solar system, perhaps the universe, and so should the study of environmental history. 

That’s because changes in the environments of the solar system have shaped, and – increasingly – been shaped by, human history. In Ripples, I show that fluctuations in the Sun’s output, for example, cooled Earth’s climate before the onset of global warming. Changes in its activity nearly provoked nuclear war and damaged electrical grids. 

Dust storms on Mars led to “discoveries” of extraterrestrial life, and inspired some of the first articulations of what we might call the Anthropocene. They even defused Cold War tensions when they encouraged research that revealed the danger of nuclear winter. Comet explosions, on Earth and on Jupiter, helped motivate robotic missions that added new craters to asteroids and changed their orbits. The list goes on. 

So here’s a definition of environmental history that I’d encourage us all to use. We study the mutual interactions, in the past, between humans and the rest of the universe. 

It’s a big topic, and we’ve only begun to explore it.  

The following two tabs change content below.

Dagomar Degroot

Dagomar Degroot is the 2024/25 Baruch S. Blumberg Chair in Astrobiology, Exploration, and Scientific Innovation at the Library of Congress, and Associate Professor of Environmental History at Georgetown University. He hosts The Climate Chronicles, a podcast on the history of climate change.

NiCHE encourages comments and constructive discussion of our articles. We reserve the right to delete comments that fail to meet our guidelines including comments under aliases, or that contain spam, harassment, or attacks on an individual.