It is difficult to look up at the towering trunk of an ancient tree and not feel a sense of awe. As Pulitzer prize winning novelist, Richard Powers, puts it, ‘Trees are among the very largest, longest-lived, most successful, and most collaboratively social forms of life on the planet. They talk to and nourish one another, remember the past, and predict the future. What’s not to love?’. As a tree-lover myself, I often marvel at these great, majestic protectors that are a silent source of solace and inspiration for many of us.
In his most recent book, The Overstory, (2018) Powers addresses the question of what the world looks like from the non-human perspective. Specifically, that of the trees, and the complex and highly sophisticated networks of which they are part. One of a new and growing climate fiction genre, The Overstory, Powers tells us, aims to explore what the world would look like from the trees’ point of view.
What’s not to love about trees?
Powers read over 120 books on trees as part of his research for this novel and admits that it changed the way he thought about the living world. His research, he tells us, led him to discover that trees engage in social behaviours, communicating with one another through a vast network of roots. They also share significant quantities of DNA with us. And although he acknowledges how fantastical this might sound, all these qualities are quite real, he assures us. Drawing on the ideas of American transcendentalists, Emerson and Theroux, he acknowledges their contribution along with that of the native American beliefs. Thus providing a new understanding of the reciprocal relationship between humans and nature. ‘There is no understanding of myself separate from the wider world in which I exist.’
For centuries trees have been a central part of human life, providing wood from which homes, transport and even weapons were made. Recently, trees have been at the center of the climate change debate. It has long been assumed that they are generally advantageous for the environment. Trees absorb noxious gases such as nitrogen oxide and carbon monoxide and release clean oxygen into the air. They help reduce landslides and flooding, their roots filter the ground water. They provide homes for a wide variety of plant and animal life thus supporting biodiversity. Last but not least, they are job creators and their mental health benefits are numerous. Indeed Germany launched the Bonn Challenge in 2011. A global initiative aimed at restoring 350 million hectares of trees by 2030. So far almost 50 countries have taken up the challenge.
Are trees the answer to climate change?
Perhaps this is what prompted a group of scientists at the Swiss Federal Institute of Technology to embark on a project designed to map how much additional tree cover the earth could accommodate. This excludes existing forests, agricultural and urban land. Their findings suggest that ecosystems could support almost 1 billion hectares of additional forest, involving more than 500 billion trees. They calculated that this would have the potential to cut the atmospheric carbon pool by about 25%.
Responses were ecstatic – plant trees and climate change can be significantly stalled! Since then, more experts have weighed in on the issue and, perhaps unsurprisingly, it is not as simple as that. Aside from the legal and economic challenges of filling said spaces with trees, previous projects of this nature have shown that trees must be carefully matched with the ecosystems where they are planted. If not, their effects can be negative rather than positive.
But there is more to it than this. Trees are far more complex than we imagined. As they live, grow and die, research has found that trees interact with the air around them in highly sophisticated ways. Swapping carbon, light, water and an array of chemicals with the air around them, they interact with the climate in ways that we do not yet fully understand. Research has found that clearing forests liberates the carbon stored in trees, bad. But it also increases the Earth’s albedo (the amount of light that it reflects), good.
The albedo of the earth plays a key role in determining the temperature of the planet. Forests at higher latitudes with dark leaved coniferous trees cover what might otherwise be light or snow-covered ground. This decreases the Earth’s albedo, leading to global warming. However, tropical forests that grow faster and transpire large amounts of water, help cloud formation and thus assist in climate cooling.
Richard Powers: hopeful for trees, less so for humans.
Just how forest chemicals interact with the climate is being researched by scientists around the world. Researchers are using a 325 meter tower in the Amazon to monitor carbon, water and other chemical changes over a 100 square kilometer area of rain forest. Smaller, similar research towers have been erected in other parts of the world too. NASA has launched the Global Ecosystem Dynamics Investigation and the Ice, Cloud and Land Elevation Satellite-2. These are designed to provide a more consistent global picture of forests’ carbon stores.
More research is always welcome. Yet many scientists say that we can’t afford to wait, we need to take action now. Richard Powers is sanguine about the future of trees. ‘Trees have survived cataclysmic changes in climate and several periods of mass extinction. I’m very hopeful for trees.’ Less so humans, ‘We will have to learn to resign ourselves to the influence of the earth, or we will disappear.’
