The “Ghost Forest” was in place by dawn – just as Angela Palmer had promised it would be. Right there, close to Nelson’s Column in Trafalgar Square, were the massive rainforest stumps that she had somehow managed to bring over from Ghana in the hope of shaking London to its roots.

Most people initially questioned the Oxford artist’s sanity when she had first outlined her plan to plant a powerful visual statement about climate change in the heart of the Capital.

Even Antony Gormley, the radical sculptor who gave us The Angel of the North and the giant nude figure that looks down on Broad Street, Oxford, dismissed the idea of a Ghost Forest in Trafalgar Square as “impossible”, when the pair met at a dinner at Exeter College, Oxford.

It has meant moving heaven as well as a good deal of earth to realise her artistic vision, to say nothing of Ghanaian bureaucrats and the Greater London Authority. It also required three trips to west Africa, to become an expert on the dirt tracks that pass for Ghana’s transport system in the rainy season.

But on Monday morning, London awoke to find ten large tree stumps, most with their buttress roots still attached, placed opposite the National Gallery.

Before becoming an artist, Angela had in the 1980s and 1990s held senior posts as a journalist: at The Observer she was news editor and then magazine editor before becoming editor of Elle. Through Sunday night, though, she worked to keep a very different kind of deadline as cranes shifted the tree stumps, one weighing 15 tonnes, into position.

The trees were originally to have been exhibited in an upright position but having seen the roots exposed and cleansed of soil in Africa, there was a change of plan.

“It was like seeing their nerve ends, in fact the nerve ends of the planet. I want to elevate the rainforest literally and metaphorically, just like Nelson,” said Ms Palmer, a mother of three, who lives in North Oxford. From now, until Sunday, the tree stumps will lie on their sides on plinths.

The stumps, of nine different species from the Suhuma forest in Western Ghana, were shipped to Tilbury docks, before being delivered by road in a huge logistical operation requiring the part closure of Trafalgar Square to pedestrians.

While Ms Palmer is confident that Londoners and visitors to the capital will see the stumps as beautiful sculptural objects, the purpose of such effort goes beyond artistic ambition: the trees are there to deliver a message from the rainforest — dramatically raising public awareness of the connection between deforestation and climate change.

And to ensure the message is delivered where it really matters, like Birnam Wood in Macbeth, the ghost forest will soon be on the move.

From London it will go to Copenhagen, to coincide with next month’s UN Climate Change Conference, a meeting that will be attended by 8,000 delegates from 192 countries.

As she anxiously monitored the movement of her precious trees from the docks, Angela said she was happy for people to enjoy and interpret the Ghost Forest on any level they wanted: as beautiful objects; a scene of devastation and degradation, perhaps evoking Paul Nash’s rendering of the First World War landscape where only splintered tree stumps remained; or even as an an overt piece of political activism and a call to arms.

“I like the idea of viewing the trees as ambassadors for all the rain forests of the world.

“Upright the full-grown trees would match Lord Nelson’s column at 169ft. But there is no right or wrong response,” she said, in between frantic calls to engineers and about a meeting with Ken Russell. It turns out that she had managed to recruit a small army of Oxford University specialists to help her from the department of engineering, the Environmental Change Institute and Oxford Centre for Tropical Forests.

“A lot of people at the university really bought into the project, like this wonderful guy at Plant Sciences, William Hawthorne. He happens to be a world expert on Ghana’s rainforests.”

When I mention how well organised the operation is, she points out that the original plan was to site the Ghost Forest in Parliament Square, a fitting place some might say, with so many soon- to-retire MPs managing passable impressions of the living dead.

When she first approached the Greater London Authority with the idea she was brushed off.

But by chance, her friend, the broadcaster Martha Kearney, happened to be interviewing Munira Mirza, the mayor’s new director of cultural policy, and agreed to mention the idea. “Somehow she managed to muddle her squares and said: ‘Angela would really like to get Trafalgar Square’.”

Ms Palmer is nothing if not well connected, having worked on the Times and Daily Telegraph and staged exhibitions at the Royal Academy and Modern Art Oxford. Her husband, Jeremy Palmer, has worked in financial services for over 25 years and has held senior management positions in private banking and investment banking in both Asia and Europe.

He is presently chairman of governors at Magdalen College School, Oxford.

The project has earned her the sobriquet Absent Angela, she jokes. “It has meant being away a lot. But I would tell my abandoned husband and children that it’s all in the name of the planet.”

She had quit journalism to become a student at the Ruskin School of Drawing and Fine Art in Oxford. One of her most treasured memories from her time at The Observer was coming up with a “buy the paper and win an island” idea to boost circulation. Being on a restricted budget, she was only able to afford an uninhabited island in Newfoundland, before being quickly told to “unbuy it”.

But much of her art has continued to be seriously newsworthy. Once, while sketching corpses in the University Medical Schools, she hit on the idea of using MRI scanners to create three-dimensional representations of the human form on multiple sheets of glass. She applied the technique to one of the Egyptian mummies at Oxford’s Ashmolean Museum, using 11 sheets of glass to create a 3D image of a little boy.

The results were intended for a her final show at the Royal College of Art but then after researching a college project she had a dream. “I dreamt I was displaying physical representations of both the most polluted and the cleanest places on earth in a stark white gallery,” she recalled.

On waking, she followed the directives of her dream, and spent a week in the coal dust-covered Linfen in China and the super-clean Cape Grim in Tasmania, Australia. The resulting art exhibit, Breathing In, is also on show until November 22 at the Wellcome Collection on Euston Road, London.

The idea of the Ghost Forest came to her at a “sustainaball” in aid of the Oxford-based charity Earthwatch.

Dressed as a sunflower, she met another old friend, Andrew Mitchell, who as well as running the Global Canopy Programme, acts as an adviser to Prince Charles. When he suggested recreating a rainforest by drawing its rings on sheets of glass, she replied: “Why distance people from the real thing? Why not bring a real rainforest tree into the centre of London and show what mighty beasts are being destroyed every second?”

She readily admits to becoming obsessed with climate change and set about finding her trees. She eventually chose Ghana, after an Oxford hardwood importer pointed out that the country, 3,000 miles due south from Trafalgar Square, had over the last 50 years lost 90 per cent of its primary rainforests.

But Ghana could also deliver a message of hope, given that it is now at the vanguard of responsible and sustainable forestry in a bid to retain its forest canopy. Strict regulations now limit the felling of trees. To reflect this, only a couple of trees in the Ghost Forest have been logged, the rest fell naturally.

She travelled to the forests of Ghana to see the first stumps earmarked for the project. Lethal marching ants, a black cobra and a scorpion were all encountered on the journey, along with a black leech which left blood pouring from a finger. But that was nothing compared with the fear she experienced watching a tree being felled. “I was warned that there was a 30 per cent chance of the tree falling the wrong way,” she recalled. “Someone told me to stick close to the trunk as there would be plenty of time to escape. For a few seconds the ground trembled and there was an almighty crack.

“When we found our driver he was stuffing vast quantities of mahogany bark into string bags. Apparently, soaking the bark in gin makes a wonderful aphrodisiac.”

The Arts Council agreed to support the scheme, with the Deutsche Bank as the main sponsor for this remarkable cityscape installation.

While planning the ghost forest project, she came across something that intrigued her in an Oxford auction house catalogue. It was a warrior’s stool that once belonged to a queen of Ghana, and was a sacred object to the Ashanti tribe.

Ms Palmer showed me the plaque on the stool.

It read: “Stolen by the British from the Queen’s palace in 1900 by H. B. W. Russell, CMG”.

Her plan is to return the precious throne to the current King of Ashanti in Trafalgar Square, which may feel to him strangely just a little like home.