Nature is a necessity.
Humans have some basic needs. Food, water, and shelter are the fundamental biological needs without which we will die. But to go beyond mere survival, to be whole, there are some psychological needs that must be fulfilled. Nature is one of these. It may be one of the most important and it is also one of the most neglected.
In his essay Wordsworth in the Tropics, Aldous Huxley distinguishes between the tame, cultivated Nature of the English country garden (the virtues of which are extolled by Wordsworth) and true Wilderness which, although "marvelous, fantastic, beautiful", can also be "foreign, appalling, fundamentally and utterly inimical to intruding man". It is "alien to the human spirit and hostile to it."
At minimum, I believe access to Nature is a requirement for a worthwhile, healthy, sane life. The thought of living in an urban highrise with a view of only other skyscrapers is hellish to me. To only allow my feet to touch concrete and never dirt, moss, fallen leaves, or sand; to only be exposed to fluorescent lighting and climate-controlled air and never feel sun or rain or breeze on my skin; to see only manmade shapes with everything at right angles and never to let my eyes wander among the intricacies of bark on tree limbs or rest in the symmetry of leaves; to constantly be exposed to the din of human life and enterprise and never the tranquil lull of birdsong or the near-silent hush of an empty field at night is to become malnourished, deformed, and demented.
One can live a life in the city and fall into a pattern in which there is almost never a chance to be exposed to Nature. Or one can find small ways to incorporate Nature into even an urban lifestyle (Lyanda Lynn Haupt wrote a good book about this called The Urban Bestiary). The key is finding the right balance; the ideal being to live in a place that is suffused with Nature while providing the necessary infrastructure for our modern lives and also having relatively fast and easy access to Wilderness.
Even when I have access to Nature, I still crave Wilderness. Wilderness may be, as Huxley says, alien and hostile to the human spirit, but that may be exactly what makes it inspiring. It pushes us to a realm of non-human concerns and forces us outside of ourselves, making room inside of us for the transcendent. Wilderness seems to be where what is left of the magic in the world still resides. Yes, it is wild and dark and uncontrollable. But belonging to a culture in which we have sanitized and motorized and categorized everything into marketing verticals, we need to expose ourselves to the wild to remind ourselves that we are animals, too. We must not neglect that animal part of ourselves because it is part of what makes us human. Without it, we become frighteningly like robots.
A hike in the woods, a kayak trip down a river, or an afternoon on a lake in a canoe. These are essential escapes for me as a writer because they are necessary for me as a human being. Without them, my life becomes unbalanced in ways that nullify any efforts at creation. You can't make something when you are empty. In Nature and in Wilderness, I find endless inspiration. Describing the beauty and capacity for solace as well as the vast, irrational, frightful quality that inspires terror and dread is probably the main subject and theme of most of what I write. Writing and storytelling are how humans make sense of our lives and our place in the universe. That exploration is inseparable from Nature and requires the perspective upheaval caused by encountering Wilderness.
For further reading on the importance of our connection to Nature and Wilderness, I highly recommend the writings of John Muir and Rachel Carson. You can also find other books on the subject on my Goodreads Wilderness shelf.