Robert Macfarlane spells out the ABC of landscape

But it's the oriental plane tree - possibly a couple of hundred years old (no one knows for certain) - that he is particularly keen to show me. A huge, bare trunk, its bark sloughed and mottled, its nodes (Rhizomes if you want to be scientific about it) stretching out towards the college. We both stand around for a moment and start imagining the tree's steady spread as a botanical slo-mo assault on encroaching humanity.

Is there a workable metaphor in there for a meeting with Macfarlane? The idea of the slow, stately pleasures of the natural world. Perhaps, but in conversation it's not clear that he feels nature is going to come out on top.

The Cambridge professor and author has spent his writing life engaged with the natural world and how it co-exists in the language and the mind of humanity. He is not a nature writer as such. He dislikes the term. But maybe you could call him a landscape writer, a writer of place, one of the pioneers of the current efflorescence in the genre that has led us in the last year to such fine books as Helen Macdonald's award-winning H is for Hawk and William Atkins's The Moor.

In 2003 Macfarlane published his first book, Mountains of the Mind, which he followed up with The Wild Places in 2007 and The Old Ways in 2012. Holloway, a collaboration with the artist Stanley Donwood (best known for his Radiohead album covers) and the writer Dan Richards, also followed.

And now he is about to publish Landmarks which is in some ways a stocktaking exercise. If the previous books saw him go out into the world, Landmarks sees him go deeper into the word. He does get out of his book-lined Cambridge office at points in its 350-plus pages, but really it's an attempt to grapple with some of his literary forebears; the writers who made him look at the natural world with new eyes as he grew up. Nan Shepherd, the early 20th-century writer on the Cairngorms whose book The Living Mountain transformed Macfarlane's idea of the mountain landscape. The late Roger Deakin, whose book about wild swimming, Waterlog, has spurred so many to take to the tarns and rivers and streams of Britain. JA Baker's The Peregrine. The various writers who have tackled the subject of Edgelands, those bits at the edge of cities that chafe against and crumble into the rural; what the Highland Agency calls - in a beautifully Ballardian description - the "soft estate".

Words matter here too, because each chapter also contains a glossary of words drawn from poetry, from the common tongue of Britain's various regions, from Gaelic. The book begins on Lewis with Macfarlane being handed the peat glossary, a word list of the hundreds of Gaelic terms for the moorland of the island. A world in words. Words that Macfarlane fears we might lose.

In the introduction to Landmarks he cites Oxford University Press's recent decision to delete words such as acorn, bluebell, conker and pasture - "the ABC of the landscape really" he suggests - from the Oxford Junior Dictionary, replacing them with the likes of broadband, chatroom and voice-mail. "Those two moments - a wealth of words and a culling of words - set me going," Macfarlane says as we settle down in his university study.

The gift of language and a loss of language. The fear is the latter is winning. And that leads to a question. What will disappear with that loss? Macfarlane is emphatic: "The reduction of any kind of engagement with notions of nature," he says simply. "Nature as a category has become arguably extinct. Bill McKibbin writes in his book The End of Nature in 1988 that nature is more or less at an end because there is no aspect of the planet that is uninfluenced by us. It's a very powerful notion that we might be living through the Anthropocene era and that you and I have seen the last years of the Holocene.

"I feel that if we lose forms of knowledge, forms of vision and forms of language that acknowledge the way we are shaped by landscape, shaped by nature, we slide off into abstract space. I don't know what the outcome of that will be but I'm fairly sure I won't like it."

In the book he worries that we are in danger of reading the landscape in purely "use value" terms. He hopes that writing, that words themselves, might challenge that. But not, he admits, defeat it. "No. This is not a magic spell that will cast us back into rabbit skin and caves and will see us at one with the Mother Goddess."

Does he fancy that then? He laughs. "No, not at all. I benefit from roofs, central heating and satnavs as the rest of us do and I'm very grateful for those things. But one doesn't need to entertain a kind of absurd regressiveness to feel enriched by and to some degree changed by and graced by encounters with landscape and nature in and of its own right, for and of its own sake.

"We typically think of what places do for us and for a long time now I've been asking what places do to us, the way they make us think, the way they make us feel, the kinds of beauty and grace and wonder. So if that's a way of slipping the use value lens even temporarily it seems an exciting and valuable thing to do. And the book ends with children. Children are for a while pre-economical and that's why they're astonishing creatures to be around because they're not always looking for transaction and payment for what they do."

Just think, he says, of the landscapes of children's literature; the deep, dark woods, the faraway places, the winter landscapes of Philip Pullman and Hans Christian Andersen's The Snow Queen. "Children's literature is rich and thick with places of retreat and test."

By contrast our own children's worlds are shrinking and shrinking. We keep them on a tight rein, don't let them out to explore, we divorce them from the world around us.

We are all guilty of this. Macfarlane too. "Like you," he says, "I'm an anxious helicopter parent."

Am I making him sound doomy and depressed? I don't mean to. In person and on the page he is delightful company. And to be fair, the fears that underpin Landmarks are balanced by its glories. A love of language. The sense of being present in and responding to the landscape.

But then most of us don't live there any more. We are urban beings. Inevitably then, I have to ask, is this conservatism dressed up in fine language (because, let's be clear, Macfarlane is a beautiful writer. His words have a tactile immediacy, a flinty materiality)?

He thinks not. "Not all forms of looking back are retrograde. Not all futures are rosy. So to feel anxious at change is not necessarily to feel conservative. Frederic Jameson says nostalgia can be a radical force because what you are dissatisfied with is the status quo. And Jameson is a Marxist cultural theorist."

And he points out his books are "I hope, thick with an acknowledgement of infrastructure, ownership, all of the extraordinarily complex business of contemporary landscape."

And nature is part of the urban landscape too. It's close at hand. He tells me he took his kids to the local chalk pits at the weekend. There's a peregrine nest in the pit, just below the mobile phone mast. The pits provided the chalk that built Cambridge. "And now they're recovering. Rewilding in that sense. And my children were leaping up and down in the claggy chalk clay mix and that's the nature I live in."

That's the nature we all live in. And, like that oriental plane tree, it is creeping closer. Up through the cracks in the concrete. And onto the page. For the last 10 years and more landscape writing has been on the rise. Macfarlane wonders if that might be tied to a realisation that climate change is a clear and present danger at the start of this millennium.

"Something about the nature of that imaginative experience of being subject to and implicated in and seemingly powerless to change a context of slow, creeping damage has been, I think, very stimulating to a certain kind of writing. And that's why it tends to be characterised often by a sense of loss, a sense of elegy, a sense of love and a sense of wonder.

"And then you had foot and mouth. Suddenly the countryside is an industrial site and a site where the industry has failed and so mass disposal of bodies must go on. The pyres, boltguns, sheep corpses. Just incredible moments of affront to the imagination. The countryside is no longer a place of retreat and calm if ever it was that. It's a place of mass slaughter and body disposal."

What can words do against such horrors? He is not optimistic but he cites the example of John Muir, whose writing helped inspire President Roosevelt to inaugurate federal protection for landscapes and set up the Sierra Club which lobbies for the environment. Ideas, words, he says, can change how we think.

"In an odd way the future is shaped by emotion and imagination as well as by policy and consumption. And Muir's work has lived an astonishing afterlife and now it finds its way into the lives of hundreds of thousands of young people from every background you could imagine. This is an incredibly hopeful vision of what writing can do."

The words we use are a form of history. Maybe, if we pay attention, a vision of the future too.

Landmarks, by Robert Macfarlane is published by Hamish Hamilton, priced £20.

ROBERT MACFARLANE ON NAN SHEPHERD

"Reading her changed the way I moved in mountains. She abolishes the idea of the summit. She says we shouldn't be driven to the top. We shouldn't suffer from summit fever. That there is more to see to know, more wonder to be found in the wandering and in walking aimlessly. She calls herself a peerer into nooks and crannies, which is beautiful. She says we walk into mountains not up them and she also says - in particular with regards to the Cairngorms - we need to see a living mountain a total entity instead of seeing just the pinnacle."

Did you have summit fever before you read her?

"Yes, bad. I still have it. I had it very strongly from [the age of] 12 to 23, and at 23 I fell in a glacier and fell off a mountain and those two things caused a major reorientation. And then I became a father not long after. So maybe it wasn't all Nan. Maybe it was that crevasse as well."

ON WINDFARMS

"I am delighted that the mega farm didn't go ahead on Lewis. I'm a not insubstantial shareholder in a community wind farm on Lewis which is highly generative and appropriate to the landscape. And I would have very little objection if a windfarm turned up pretty close to my house because I don't find the farmland terrain of most of southern England particularly worthwhile. But we don't get the wind."

ON MOTORWAYS

"It's an incredible contemporary habitat that has arguably done more for the kestrel than the Wildlife Trust. I count the raptors if I'm making a journey across southern England and I see more from a car than I do on foot."

ON HIS LOVE OF SCOTLAND

"I'm not a Scottish writer but my writing is Scottish. I was born in England, I was brought up in England, and I live in England. But my imaginative and creative life is deeply bound up with Scotland and I've written at least as much about Scotland as about England."

ON WHETHER LANDSCAPE WRITING HAS A NATIONALITY

"It's a deeply interesting question and one of my instincts is to say that it works by terrain and it works by bioregion. And yet you can't shake the nation out of landscape just as you can't shake the landscape out of the nation, and like everyone else I watched with utterly compelled fascination over the [Scottish] referendum. And one of the questions I was asking myself was 'how would Nan Shepherd have voted?' and I think the answer is she would have been a Yesser, even though for her the Cairngorms were their own territory."

ON HIS FAVOURITE WORD FROM THE GLOSSARIES

"Roarie-bummlers, which I think sounds like a kid from Eton but is a Scots word for thunder clouds, is just a beauty. It's fond and it's funny, but when you've been under a sky full of roarie-bummlers you know it."