'As the planet warms, the forest is on the move'

You have a heartbeat. Did you know that the planet has one too? In fact it has more than one. 

Every day plants create a pulse of oxygen as they breathe in carbon dioxide and exhale oxygen. And every year, deciduous plants and trees photosynthesise during the spring and summer and then shut down for the winter, creating a burst of oxygen in springtime. 

And lastly, the most amazing and dramatic of all, the slow heartbeat of ice, rising and falling like a white blanket over the top of the earth every 100,000 years. The ice ages have defined life on Earth for millions of years and, each time the ice has retreated north, the plant kingdom has followed on its heels and then been obliterated again, rising and falling, like breath.

As the lichen, moss, then grass and trees has colonised the rock, the advancing treeline has transformed the surface of the planet into a habitable crust of soil and plants. There is barely a square inch of the northern hemisphere that has not been passed over, and blessed, by the treeline. If you are reading this in the UK, the spot where you are standing was almost certainly once forest.

The UK is a boreal nation, once sharing many of the same species as the taiga of Russia and the northern woods of North America – beaver, lynx, deer, ptarmigan, bears. But our forest has long gone. There are some scraps remaining in Scotland, but they are fragments only – glimpses of what might have been, like the emerald islands in the middle of Loch Maree, which have been continuously wooded for 8,000 years. 

There was once too, a natural treeline in Scotland – a zone beyond which trees would not grow because altitude and temperature were prohibitive. There might be still, but we don’t know because the trees are no longer there to mark the line.

Across the world, that line is creeping north with increasing speed. As the planet warms, the forest is on the move. The trees are on the move, they shouldn’t be, and this surprising fact has huge consequences for all life on Earth.

I went north, to the Arctic Circle, to catch a glimpse of the future where the planet is warming fastest: where the trees are on the move more than ever. I was completely unprepared for what I found. Forests have been shifting north since World War Two, trees are popping up where they have no right to exist and all the other denizens of the forest, including humans, are confused.

The clues to the changes underway and what they might mean for humans and non-humans alike are to be found in the past: the study of rocks, ice and trees. And if we are to find new, more healthy and respectful ways of co-existing on this planet with other species, then we must pay attention to older ways of living in harmony with the forest, ways of life practised by indigenous peoples of the woods the world over. 

On my journey I met the Sami people of Norway herding reindeer on the tundra. The advancing trees for them spell trouble – the reindeer cannot access the grazing on the tundra and in recent years many have died of starvation.

In Siberia, I met members of the Nganasan and Dolgans whose lives have been turned upside down first by communism then by its ending. The larch there is not moving yet, but the inhabitants of the forest – birds and flowers from the south – are already appearing. The Koyukon of Alaska first noticed changes signalled by birds a century ago. 

How the people of the north are meeting the changes and challenges of global warming has lessons for us too. The Anishinaabe of Canada have confronted the traumatic history of colonialism through a ‘back to land’ movement of healing camps and in the process created the largest protected enclave of old growth forest in North America. The Sami of Norway hold to an old concept of ‘biregupmi’ meaning ‘enough’ – one should only take what one needs, not the maximum that can be harvested without destroying the resource; the exact opposite of the modern definition of sustainability.

The lesson for me of the journey along the treeline was an understanding that we have always been creatures of the forest. Trees and humans share the same climate niche. If we want to co-evolve with them in a warming future, then we need to pay attention and follow their example.  

Trees offer us a warning but also consolation, and in their generous, creative and social example they show us a way out of the dead end we have driven down. The Treeline is an invitation to take a walk in the woods and participate in the infinite, mysterious and majestic unfolding algorithm that is the co-evolution of all life on Earth.

The Treeline by Ben Rawlence is out now (Jonathan Cape, £20). Ben Rawlence is the director of Black Mountains College in Wales.

@BenRawlence

This article is taken from The Big Issue magazine. If you cannot reach your local vendor, you can still click HERE to subscribe to The Big Issue today or give a gift subscription to a friend or family member. You can also purchase one-off issues from The Big Issue Shop or The Big Issue app, available now from the App Store or Google Play.