When people talk about “nature,” they’re generally talking about things that aren’t made by human beings. Rocks. Reefs. Red wolves. But while there is plenty of God’s creation to go around, it is hard to think of anything on Earth that human hands haven’t affected.

In the Brazilian rainforest, scientists have found microplastics in the bellies of animals ranging from red howler monkeys to manatees. In remotest Yakutia, where much of the earth remains untrodden by human feet, the carbon in the sky above melts the permafrost below. In the Arctic Ocean, artificial light from ship traffic—on the rise as the polar ice cap melts away—now disrupts the nightly journey of zooplankton to the ocean surface, one of the largest animal migrations on the planet. The remote mountain lakes of the Alps are contaminated with all kinds of synthetic chemicals. Polar bears are full of flame retardants. Cesium-137, fallout from nuclear bomb explosions, lightly rimes the entire planet.
These examples are mostly pollution—nuclear, carbon, chemical, light—but I raise them not to highlight the ways human industry and technology degrade the environment but to note how the things humans build change it. Nobody really knows what the exact effects of all that will be, but my point is that no part of the globe is free of human fingerprints. We have literally changed the world.
We’ve changed ourselves as well. Humans are especially adept at bending human nature. Everything about us is up for grabs—appearance, health, our very thoughts. Pharmaceuticals, surgeries, vaccines, and hormones give us longer lives, take away our pain, ease our anxiety and depression, make us faster, stronger, more resilient. We’re getting glimpses of technologies that will let us change who our children will become before they’re even born. Electrodes implanted in people’s brains let them control computers and translate thoughts into speech. Prosthetics and exoskeletons straight out of comic books restore and enhance physical abilities, while gene-editing technologies like CRISPR are rewriting our very DNA. And meanwhile, people have taken the sum total of all the information we have ever written down and poured it into vast calculating machines in an effort—at least by some—to build an intelligence greater than our own.
So what even is nature, or natural, in this context? Is it “environmentalist,” in the conventional sense, to try to preserve what one could argue no longer exists? Should we employ technology to try to make the world more “natural”?
Those questions led us to approach this Nature issue with humility. We try to grapple with them all the time—MIT Technology Review is, after all, a review of how people have altered and built upon nature.
And it’s a place to think about how we might repair it. Take solar geoengineering, for example—a subject we have covered with increasing frequency over the past few years. The basic idea of geoengineering is to find a technological fix for a problem technology caused: Burning petrochemicals to fuel the Industrial Revolution turned Earth’s atmosphere into a heat sink, fundamentally breaking the climate. Some geoengineers think that releasing particulate matter into the stratosphere would reflect sunlight back into space, thus reducing global temperatures. After years of theoretical discussions, some companies have begun to actively experiment with such technologies. This might seem like a great way to restore the world to a more natural state. It’s also fraught with controversy and peril. It could, for example, benefit some nations while harming others. It may give us license to continue burning fossil fuels and releasing greenhouse gases. The list goes on.
Nature isn’t easy.
In our May/June issue, we have attempted to take a hard look at nature in our unnatural world. We have stories about birds that can’t sing, wolves that aren’t wolves, and grass that isn’t grass. We look for the meaning of life under Arctic ice and within ourselves—and in the far future, on a distant world, courtesy of new fiction by the renowned author Jeff VanderMeer. I don’t know if any of that will answer the questions I’ve been asking here—but we can’t help but try. It’s in our nature.