Trees have long been at the foundation of religious, mythological and cultural life throughout the world – from Ancient Egypt, whose people believed that the sun god Ra emerged each morning from between twin sycamores standing at the gates of heaven, to the Celts of Gaul, who believed trees to be sources of wisdom, immortality and renewal.
In the book of Genesis, the Tree of Life and the Tree of Knowledge are depicted at the centre of the Garden of Eden. It was also a common practice among proselytising Christians of the sixth century to graft Christian theology onto existing rites – in the case of pagan tree cults this involved cutting down the sacred grove and building a church on the same site.
In India it is believed that the ghosts of Brahmans live in pipal (or Sacred Fig) trees awaiting reincarnation. For Muslims, the Lote-Tree is a metaphor for the boundary between the human and the divine. The rivers of life flow from the four boughs of the Buddhist Tree of Wisdom; meanwhile the great ash tree of Nordic myth, Yggdrasil, which connects heaven, earth and underworld with its roots and boughs, is a fine example of a ‘world tree’ – the most ancient cross-cultural depiction of the universe’s composition.
And let us not forget, of course, the modern tradition of the Christmas tree.
Thanks to climate change we are rediscovering why man through the ages has instinctively protected and revered the largest plant on earth, in the process granting it many holy names (of which the ‘Tree of Life’ is the most telling).
We are all now familiar with the greenhouse effect: the phenomenon whereby heat radiating from Earth is trapped in the atmosphere by certain greenhouse gases, among them carbon dioxide (CO2). Since the onset of the Industrial Revolution, CO2 emissions have increased dramatically as more fossil fuels are burned for both domestic and industrial purposes, raising surface temperatures and as a result threatening many of the world’s plants and animals – perhaps even humans – with extinction.
What we are not so familiar with is the fact that trees sequester CO2 from the atmosphere during photosynthesis, a process which forms carbohydrates (used in plants’ structure and function) and returns oxygen to the atmosphere as a by-product. In this sense, trees act as a ‘carbon sink’ – planting them remains one of the cheapest and most effective means of removing excess CO2 from the atmosphere.
The US Forest Service estimates that during the period 1952-92, the forests of the US sequestered a net of approximately 309 million tons of carbon per year, offsetting approximately 25 per cent of domestic anthropogenic carbon emissions during the same period. Furthermore, estimates suggest that over a 50-year lifetime, a single tree generates $31,250 worth of oxygen, provides $62,000 worth of air pollution control, recycles $37,500 worth of water and protects against $31,250 worth of soil erosion.
In addition to the extraordinary figures above, studies around the world have found that trees:
• save up to 30 per cent of nearby buildings’ energy consumption, by moderating the local climate;
• increase property values by up to 15 per cent;
• reduce wind speeds, topsoil erosion and rainstorm impact and provide a natural alternative to expensive flood control systems that depend on hard engineering;
• calm traffic, since a treeless street is perceived by motorists as wide and hazard-free, encouraging them to speed;
• buffer pedestrians from moving vehicles and flag upcoming curves for motorists;
• enhance local economic performance by attracting businesses and tourists – people linger and shop longer on tree-lined streets, apartments and offices rent more quickly and have higher occupancy rates, and businesses report greater productivity and reduced absenteeism among workers;
• improve social cohesion and reduce social service budgets – for example, researchers Kuo and Sullivan found that 14 per cent of the residents they interviewed living in barren areas have threatened to use a knife or gun against their children, versus just three per cent of the residents living in green areas; and
• reduce noise pollution, by acting as a buffer and absorbing 50 per cent of urban noise.
BRANCHING INTO HEALTH
The health benefits of urban trees rest on two key functions: pollution-control and the creation of tranquil environments. A large beech tree, for instance, not only filters polluted air but also provides enough oxygen for 10 people, catches particles and dust on its leaves and reduces solar radiation, thus positively impacting on the incidence of respiratory ailments, such as asthma, and skin cancer. Meanwhile this same tree, being intrinsically ‘therapeutic’, will likewise promote general well-being and reduce the incidence of stress-related illness.
Studies have shown that patients in hospital rooms with views of trees and plants make fewer requests for pain medication and experience a speedier recovery following surgery than do patients with no such views, and an emerging body of scientific evidence suggests that exposure to green areas and leafy trees may reduce the symptoms of Attention Deficit Hyperactivity Disorder (ADHD) among children and generally improve both their cognitive abilities and their resistance to negative stresses and depression.
Richard Louv, in his bestselling book Last Child in the Woods, contends that biologically we are still programmed to fight or flee. Our ancestors often couldn’t outrun their predators, but they were able to consistently outwit them – and then use the environment to recover their wits once they had escaped. Because of our ‘animal’ nature, we today find ourselves continually on the alert, chased by an unending stampede of automobiles, trucks, buses and crowds. Even in our homes the assault continues, with unsettling, threatening images charging into our living rooms and bedrooms via TV and the internet. At the same time, the urban/suburban landscape is being stripped of its peace-inducing elements, such as trees – a loss that more and more researchers believe has enormous implications for human health and child development.
WE NEED OUR HEADS REDD
Alarmingly, urban trees are being felled at an unprecedented rate. In London alone, 40,000 trees were felled in the five-year period up to 2007, for reasons that varied from subsidence to ‘trip hazard’. This is perhaps unsurprising, given our current economic model in which trees are accorded little-to-no economic value – when it comes to determining municipal budgets, it doesn’t make ‘cents’ to spend money maintaining an ‘asset’ that is not only worth nothing on the balance sheet but that also causes our properties to subside, trips us up, obscures the CCTV cameras that follow us around, houses the pigeons that soil our cars and occasionally drops fruit on our heads.
But it’s not just municipalities that have embarked on a chainsaw massacre. Rainforests, aptly referred to as the ‘lungs of the earth’, are being felled at the rate of approximately 8.5 million football pitches a year – that is, 23,483 pitches every single day. In the past 50 years, a third of the world’s rainforests have been felled and burned.
Tropical deforestation is a double negative: rainforests absorb almost a fifth of the world’s man-made CO2 emissions every year, and their destruction, in addition to diminishing this capacity, accounts for a further 17 per cent of annual greenhouse gas emissions. As a whole, deforestation and forest degradation are responsible for 20-25 per cent of greenhouse gas emissions – about the same as the transportation sector.
Fortunately it is increasingly accepted that mitigation of global warming will not be achieved without the inclusion of forests in an international game plan. The UN’s Programme on Reducing Emissions from Deforestation and Forest Degradation in Developing Countries (UN-REDD), which aims to monetise conservation efforts, is therefore expected to play a crucial role in any post-2012 successor to the Kyoto Protocol, despite deforestation having been overlooked in the 1997 agreement.
THE TIME IS NOW
Time and global warming march on, as does the steady deforestation of our towns, cities and rainforests. Given our ever burgeoning global population, forecast to hit nine billion by 2050, we will no doubt continue to clear forests to provide homes, food, fuel, clothes and other ‘stuff’.
In the face of this onslaught, the humble, life-giving tree stands little chance, especially when you consider that it is at the mercy of profit-hungry corporations – abstract entities which cannot be seen or touched but which have legal rights and market value where a tree, so long as it lives, has none.
Let us change that – and not go the way of civilisations before ours such as the Nazca people of Peru who, it is reported, literally fell with the trees they felled.
‘A fool sees not the same tree a wise man sees,’ wrote William Blake. One such wise man, John F Kennedy, liked to tell the story of French marshal Hubert Lyautey and a gardener in his employ. The gardener, on being asked to plant a particular species of tree, objected that the tree was slow-growing and would not reach maturity for 100 years. The marshal replied: ‘In that case, there is no time to lose; plant it this afternoon!’