How could we share crucial environmental knowledge with our distant descendants? When trying to communicate with people many centuries away we must consider how culture changes over time. Languages can become lost or unintelligible, just think how difficult it is to read Old English today after one millennia. The meaning of symbols can shift too – being open to recontextualisation and misinterpretation. Given that we can’t assume archives or the internet will exist in the way they do today, knowledge may have to be passed on in more creative ways instead.

In the 1980s scientists were tasked with communicating the dangers of contaminated nuclear sites at least ten thousand years into the future. The Human Interference Task Force brought together semioticians, physicists, sci-fi authors and a range of others to tackle this problem, forming a field of study that became known as nuclear semiotics. They proposed introducing menacing structures, secret societies, and – finding that stories can last longer than the languages that carry them – myths and symbols to transmit messages about the dangers of radiation across time.

Like the nuclear issue, today the sixth mass extinction – human-caused ecological collapse – presents an existential threat that requires rapid multinational action as well as long-term solutions. One such slow solution is rewilding: the large-scale restoration of ecosystems where nature is left to take care of itself, free from human interference. Yet many rewilding projects are still in their infancy: even the more established ones in the UK are less than 50 years old. To be successful, rewilding must continue long after we’re gone. Sustaining projects across thousands of years requires speculative thinking that could draw on ideas from nuclear semiotics, while also learning from those who stewarded the land before and bearing in mind those who will live with the land into the distant future.[1]

We’ve lost great forests before, fuelling fires and building ships for war and trade. For example, forests in England were subjected to large-scale felling for ship building from the 1500s: by the late 1700s, Nelson’s fleet alone is estimated to have required 1.2 million oaks, many of which would have been over 300 years old. A future society may see the same potential in the forests and having forgotten the horror of the ecological crisis, destroy rewilding sites for short-term gain. Nuclear semioticians attempted to warn our distant descendants about poisonous waste – can we do the same to ward them from the woods and protect these life support systems in the future?

We don’t have to start from scratch. Markings and myths – from witch marks to wolf tales – have warned people of the deep dark woods for centuries. One mark common on trees across England from the 1500s and later British colonies was the king’s broad arrow. Three small scratches made with quick strokes of an axe on bark warded locals away from felling them for personal use, protecting the trees so they could grow tall and straight. However, this protection lasted only until they were large enough to build tall ships when they were destroyed for imperial pursuits.

Could a small mark on bark be enough to protect rewilded woods? We might take additional inspiration from the nuclear semioticians. We could consider foreboding hostile architecture, such as concrete spikes to make land unfarmable and house-sized blocks arranged into streets leading nowhere, yet installing concrete monoliths at rewilding sites would likely conflict with habitat creation.

Still, we could let the environment speak in other ways, as some of our oldest knowledge survives through oral cultures that use landscapes to remember narratives. The author Blindboy Boatclub (David Chambers) explains how the Irish epic, Táin Bó Cúailnge, would have been told from Rathcroghan hill while pointing out the mountains and lakes that illustrate the tale.[2] The scenery keeps the story alive and the story stores knowledge about keeping the environment alive. We could use ‘the landscape as a repository for cultural data’, as Blindboy puts it, encouraging storytelling based around natural features near rewilding sites in ways that excite people enough to pass them to the next generation.

In a series of more out-there proposals, the Human Interference Task Force suggested breeding genetically modified cats that would glow when in close proximity to nuclear waste, and coding messages into the DNA of flowers that would grow near protected sites. Though these solutions were never implemented, we could still take inspiration from them. Creatures that thrive at rewilding sites could help transmit knowledge of the importance of their presence by creating music that incorporates their vocalisations, for example, as part of a plea to safeguard them and their habitat.

‘Pill iù Pill ill ill ill Eòghainn’ is a refrain from an ancient Scottish Gaelic coronach – keening or mourning song – that has been kept alive for hundreds of years, despite the language repression, through its connection to creature and ceremony.[3] The vocables mimic the memorable redshank’s call, a wading bird found near rewilding projects in Scotland today. Ritual mourning means the song is recalled with each loss: ‘What was that song you sang at dad’s funeral? Sing the one you sang for Billy.’ Embedding a similar song into the culture could help us communicate across time, so that in hundreds of years time, every vocalisation from a recovering species in rewilded woods serves as a reminder about its importance.

If we are to weather or reverse ecological collapse, it’s crucial that we pass on the relevant knowledge to ensure that recovery continues, and that this crisis is not repeated. The Human Interference Task Force suggests that a creative multidisciplinary approach could prove fruitful here too. We know songs and stories can survive for aeons, and that the land itself can store knowledge. A new ecologically-focussed semiotic task force could implant information across culture to help rewilding sites survive across more-than-human time scales, using symbols, landscapes, and stories to sing through the trees and the time warps.