We have just been asked to absorb some shocking news, courtesy of a study published in the journal Current Biology: In the past 20 years humans destroyed 10 percent — over 1 million square miles — of the planet's wilderness. Without decisive action, we will probably destroy all that remains unprotected by 2050; and that is a large expanse, approaching 20 percent of the planet's entire land-area.

This information arrives at a time when environmentalism is on sounder footing than ever before. Some of us will remember the Reagan years, when it wasn't uncommon to see bumper stickers bearing the slogan “Earth First! We'll log the other planets later.” Such sarcasm is far less prevalent in 2016. Many on the right now find it stylish both to view the planet in mercenary terms — as so many minerals and strip malls — and to advocate for protecting certain places from development. At the 100th anniversary of the National Park Service, we witnessed the bipartisan spirit of environmentalism at work when Democrat Barack Obama (our most conservation-minded president in terms of acreage saved) quadrupled the size of a marine preserve in Hawaii that was established by his predecessor, Republican George W. Bush. Moreover, hunters and fishermen — groups that trend Republican — have increasingly come to back the environmental causes their licensing fees support. As we better understand the link between eco-stewardship and healthy game, we also see one forming between conservation and conservatism.

It's not all optimism, of course. There are some who will remain unconvinced. For example, the Ammon Bundy crowd may oppose federal protections on principle (as government overreach), and they have vocal champions in Congress. And even with further government set-asides and regulations, we will be playing catch-up for decades as the repercussions of past environmental abuses continue to appear: One thinks of the recent fish die-off on the Yellowstone River; more worrisome still, the record retreat of Antarctic sea ice.

Add to this our current Republican presidential nominee, who has called climate change a Chinese hoax (even if he hopes to walk that claim back now). But whatever the battles to come, there is reason to believe that common sense and realism are winning the overall war against neglect and outright hostility on the environmental front. A Monmouth poll from January suggests that 70 percent of Americans now accept climate change as real even if they differ on its causes.

What interests me is a basic question: What is the conceptual value of wilderness? Why do we need large areas that are impenetrable to us?

The answer can't be about beauty or sublimity. Yes, many of these places are spectacular, but only in the eyes of some, and such value judgments are dubiously political. Additionally, some of our wilderness areas are downright monotonous — stands of deciduous trees that, scale aside, resemble a suburban backyard.

Sadly, the answer can't be about wildlife and biodiversity, either. While I would save every bee, bird and bear in their natural surroundings, I have met many people over the years who are content to relegate wildlife to zoos.

The answer is more elusive. The wilderness has always been both a real and imaginary frontier, and the latter depends on the former. In epic quests and fairy-tales we have strayed into fictional wildernesses that have, in turn, inspired us to value the real thing. We don't yet have other planets to log, but even if and when we do, think about the psychic toll we will pay when a generation of children must read the Brothers Grimm or Tolkien or Thoreau with no real-world corollary to the green, shady places they explore — here, on this planet. And this would not only be a loss of context for understanding imaginations past; it would diminish what we might imagine in the future. Entire cultures, religions and tribal identities have emerged from the wilderness; what will emerge from its disappearance?

Wilderness represents mystery, potential and the free space of imaginative play, without which innovation and creativity stagnate. If you don't believe me, consider how many of our great innovators have also been readers of science fiction and how many of their favorite authors based their otherworldly creations and landscapes on worldly wildernesses.

It would be a new kind of poverty to live on a planet devoid of such expanses, fully extracted, monetized and discovered. We need the wilderness — and we value it in abundance — because the paean to “progress” must also and always be an ode to the stone unturned.

Noah Comet is a professor at the U.S. Naval Academy, a conservationist, wildlife photographer and avid hiker. His email is comet@usna.edu.