The Turkish novelist Elif Shafak is to follow Margaret Atwood, David Mitchell and Sjón as one of the 100 contributors to the Future Library, an art project that will only be seen by readers in 2114, when the spruce trees to make its paper have been fully grown.

Dreamed up by the Scottish artist Katie Paterson, the Future Library is, in Paterson’s words, “a living, breathing, organic artwork, unfolding over 100 years”. Starting in 2014, each year Paterson has approached a writer to contribute a manuscript to the project, with the texts to remain secret until 2114, when the trees in Oslo’s Nordmarka forest, planted as 1,000 seedlings in 2014, will be chopped down, the paper made and the manuscripts finally printed.

“It will live and breathe through the material growth of the trees – I imagine the tree rings as chapters in a book. The unwritten words, year by year, activated, materialised. The visitor’s experience of being in the forest, changing over decades, being aware of the slow growth of the trees containing the writers’ ideas like an unseen energy – that’s something that has to come into being,” said Paterson. “The timescale is 100 years, not vast in cosmic terms. However, in many ways the human timescale of 100 years is more confronting. It is beyond many of our current lifespans, but close enough to come face to face with it, to comprehend and relativise.”

Shafak, the author of novels including The Bastard of Istanbul, The Forty Rules of Love and most recently Three Daughters of Eve, was named on Friday as the fourth writer who would be contributing – a choice Paterson described as pertinent: “Her work dissolves boundaries: cultural, geographic, political, ideological, religious and spiritual, and embraces a plurality of voices. Her storytelling is magical and profound, creating connectivity between people and places: a signal of hope at a particularly divided moment in time.”

Shafak said she was honoured to be joining Atwood, Mitchell and Sjón on the project. “It’s a very unusual project, and they’ve put so much thought and heart into it – so much faith behind it,” she said. “This entire idea of writing a manuscript that will, hopefully, be read in the future is to me like writing a letter now and leaving it in a river. You don’t know where it will go or who will read it – you just believe in the flow of time.”

She also praised the project’s international reach, with writers from Canada, the UK, Iceland and now Turkey selected. “It’s a global project, at a time when there is a lot of division in the world. One of the organisers said it is like a family tree, and I love that,” she said.

The authors are selected by a trust “for their outstanding contributions to literature and poetry and for their work’s ability to capture the imagination of this and future generations”. The length of the manuscript they write is up to them, as is its genre.

Shafak said that writing the text – she has started thinking about it but has yet to put pen to paper – was going to be a challenge. “I may do something across fiction and non-fiction. I want it to be meaningful for the people who will read it in the future, maybe kind of reflecting the concerns of our time … what it feels like to live in these liquid times,” she said. “You’re writing for people you’ll never meet, but at the same time for yourself, so in some ways it feels like a very personal, intimate project. You don’t think about the reaction, you just write because you believe in what you’re doing, so there is a very pure core to the project.”

Shafak will deliver her manuscript in the forest at a ceremony next June. It will be held, alongside Atwood’s, Mitchell’s, Sjón’s and all the future contributors’ work, in a room at the new Deichmanske public library, opening in 2019 in Bjørvika, Oslo. Its contents will remain a secret until 2114, when the anthology is printed.

Atwood has said of the project: “How strange it is to think of my own voice – silent by then for a long time – suddenly being awakened, after 100 years. What is the first thing that voice will say, as a not-yet-embodied hand draws it out of its container and opens it to the first page?” Mitchell, meanwhile, called it “a vote of confidence that, despite the catastrophist shadows under which we live, the future will still be a brightish place willing and able to complete an artistic endeavour begun by long-dead people a century ago”.