This might sound hyperbolic, but it is true: there is no longer any part of the globe that remains "natural" in any meaningful sense. Even the apparently pristine ice-clad poles are contaminated by man-made chemicals, many of which concentrate in the food chain - through fish, whales and seals - making the breastmilk of Inuit women so loaded with poisons as to constitute, in effect, toxic waste. Humanity bestrides the planet in a way no single species has ever achieved before: enough now, according to many scientists, to merit our name being applied to a new geological era, the anthropocene.
The rain that falls anywhere on the planet's surface is different in its chemical constituents from pre-industrial rain; we have doubled the natural flow of reactive nitrogen through living systems, causing enormous algal blooms, not to mention - at the last count - 405 dead zones in coastal waters around the world. There is now a third more carbon dioxide, double the methane and a whole host of artificially manufactured gases circulating in our atmosphere. We have even managed to make the entire global ocean measurably more acidic, a remarkable achievement by any standard.
Our moral and artistic senses have barely begun to comprehend the scale of what is going on. Yes, it is there in black and white for anyone to read in weighty scientific reports such as the United Nations Millennium Ecosystem Assessment. Some of these reports are reasonably readable. Some even have pictures. But works of art they are not, nor are they intended to be. This has a tangible impact: in cultural terms, we still fondly imagine ourselves to be tiny and insig nificant little creatures, beetling about on a vast planet that is relatively impervious to our presence. We terrify and titillate ourselves with stories of natural disasters - earthquakes, volcanoes, hurricanes, tsunamis - which seem to prove once again how powerless we are against the "great forces of nature".
This is a false impression: the greatest force of all is we human beings. Our collective footprint now far outreaches anything this planet has naturally produced for tens of millions of years: even the worst imaginable supervolcano would have less of an effect on the biosphere than humble little Homo sapiens so far has.
Artistic representation is integral to us ever developing a true understanding of our new place in the world. Good art bridges the intellectual/ emotional divide, communicating meaning in a way that UN reports cannot. It can help us think about why something hurts that is lost, why any of this matters, and how we might feel differently about it. It can step outside the rationalist discourse of modern scientific environmentalism into a different mental space where freer thinking is allowed and encouraged, and an impressionistic appreciation of changing nature is as valuable as rigorous facts and figures. Art should not be propaganda - but it can change minds. At its best, it is a connecting rather than a dividing force.
This is the difficult and contested territory that a new and visually stunning photographic collection, Vanishing Landscapes, occupies. Some of the images are truly shocking, such as Robert Adams's pictures of logged redwood trees in the American north-west. No one can flick through these pages and not be appalled at the scale of devastation that humanity has inflicted on the landscape: not only have the trees been cut, but the whole ground has been butchered and vast areas bulldozed over. Stumps the size of houses are upended, thrown together like so much matchwood. In the final picture of the series, Adams's wife sits hunched against a tree stump, surrounded by discarded branches and rotting timber as if by death itself. The ethereal quality of the images is highlighted by them being printed in black and white, which makes their content all the more stark.
Similarly striking are Edward Burtynsky's pictures of nickel tailings in Ontario, Canada. Bright red rivers flow through a charred and blackened landscape, reminiscent of volcanic lava flows in both colour and form. Burtynsky puts it well in the introduction: "These images are meant as metaphors to the dilemma of our modern existence," he writes. "We are drawn by desire - a chance at good living, yet we are consciously or unconsciously aware that the world is suffering for our success."
But what of landscapes in which the human impact is less obvious? Walter Niedermayr cleverly juxtaposes the human with the natural in his photographs of Alpine glaciers in Austria: on one side of the page fold sits an apparently natural icescape, and on the other people are emerging - their bright clothes the only colour in the grey-whites of the glacial mass - on duckboards from an ice cave. Other pictures in Niedermayr's series show people sprinkled over the surface of the ice, like flecks of pepper in a salt-pan. Though the figures appear tiny in comparison to the bulk of the ice on which they are walking, they also dominate it with their sheer numbers when spread out. Thomas Struth contributes photos of intact forests, each named Paradise plus a number: an Australian forest is Paradise 03, a tangled Peruvian jungle is Paradise 31. There is no evidence of human impact at all; indeed, the pictures look as primeval and verdant as the Garden of Eden itself, which I suspect they are intended to evoke.
And yet we know that, even in such landscapes as this, all is not what it seems. As the climate scientist John Schellnhuber says in an interview transcribed in the introduction: "As an image of nature, the landscape can no longer be conceived of as independent of humankind but is always something that we ourselves have created." We may not know it, but the composition of Peru's forest in Paradise 31 may be subtly different from how it would have been in a world without human beings. That is not to bemoan our presence on this earth: we have as much right to be here as any other element of the biosphere. But the converse also applies: all the species we are busily wiping out - consciously or unconsciously - themselves enjoy inherent rights of existence. If we can understand and appreciate them more, perhaps we can also learn to respect them.
"Vanishing Landscapes" is published by Frances Lincoln on 18 September (£35)