Once, while waiting for a wilderness permit at a ranger station in North Cascades National Park, Washington state, I overheard the following message, radioed into headquarters by a backcountry ranger: ‘Dead elk in upper Agnes Creek decomposing nicely. Over.’ This ranger was not only a practical and profound ecologist, she also possessed the wisdom of a Buddhist master. The ‘over’ in her communication seemed especially apt. For Buddhists, as for ecologists, all individual lives are eventually ‘over’, but their constituent parts continue ‘living’ pretty much for ever, in a kind of ongoing process of bio-geo-chemical reincarnation.

People who follow ecological thinking (including some of our hardest-headed scientists) might not realise that they are also embracing an ancient spiritual tradition. Many who espouse Buddhism — succumbing, perhaps, to its chic, Hollywood appeal — might not realise that they are also endorsing a world view with political implications that go beyond bumper stickers demanding a free Tibet.

Plenty of us recognise that Buddhist writings and teachings — especially in their Zen manifestation — celebrate the beauty and wisdom in the natural world. A monk asks a master: ‘How may I enter in the Way?’ The master points to a stream and responds: ‘Do you hear that torrent? There you may enter.’ Walking in the mountains, the master asks: ‘Do you smell the flowering laurel?’ The monk says he does. ‘Then,’ declares the master, ‘I have hidden nothing from you.’

Part of this sensitivity to nature is a Buddhist grasp of suffering, whose existence constitutes the first of Buddhism’s Four Noble Truths. It is no coincidence that Henry David Thoreau, America’s first great environmentalist, was also a student of Indian religion and the first translator of the ‘Lotus Sutra’ into English. In this classic teaching, Shakyamuni Buddha compares the ‘Dharma’ — the true nature of reality — to a soothing rain that nourishes all beings.

The pioneering ecologist Aldo Leopold wrote that to have an ecological conscience is to ‘live alone in a world of wounds’. The Buddha urged his followers to be sensitive to the suffering of all sentient beings. His First Precept is to commit oneself to ahimsa, or nonharming. The Mahayana Buddhist ideal is to go further, and to become a bodhisattva, an enlightened individual who vows to relieve the suffering of all beings. In the ‘Metta Sutta’, Theravada monks and lay adherents vow to practise loving kindness: ‘Even as a mother protects with her life her child, her only child, so with a boundless heart should one cherish all living beings.’ And here is the first verse of ‘The Bodhisattva Path’, by Shantideva, a revered eighth-century poet: ‘May I be the doctor and the medicine/And may I be the nurse/For all sick beings in the world/Until everyone is healed.’

For Buddhists and ecologists alike, we are all created from spare parts scavenged from the same cosmic junk-heap

However, for me, as a scientist, there is something much more in the Buddhist tradition than an injunction to care for other living things. This meeting of the minds, Buddhist and ecological, results from similar insights into the nature of reality itself — which is indistinguishable from the reality of nature — and of our place in the whole business.

‘I

f you are a poet,’ writes the contemporary Zen master Thich Nhat Hanh, ‘you will see that there is a cloud in this sheet of paper. Without a cloud, there will be no rain; without rain, the trees cannot grow; and without trees, we cannot make paper.’ He goes on to include the logger who cut the trees, the logger’s mother, and so forth. If you, too, can see the cloud in a sheet of paper, then perhaps you too are a poet, a Zen master — or an ecologist. Regardless of who sees it, there really is a cloud in a sheet of paper, as well as a bark beetle, a handful of soil, a bit of bird poop, even the gasoline that powered the logger’s chain saw. It is similarly possible that if you were to chronicle the history of those atoms that constitute the electronic screen from which you are now reading, you would find that they were once part of Peter the Great, a woolly mammoth, or (and!) a Komodo dragon.

The interconnected and interdependent nature of things is the heart of ecology. It is also remarkably similar to the fundamental insight of Buddhism: ‘dependent co-arising’ or pratītyasamutpāda in Sanskrit; paticcasamuppāda in Pali. Traditional Tibetan Buddhists repeat, over and over, that all things have at some time been our mothers, just as we have at some time been theirs. In both the Theravada and Mahayana schools of Buddhism, the key teaching is ‘compassion’, which means something quite different from empathy, sympathy, doing good, being nice, or easy phrases about ‘feeling your pain’.

The touchstone, instead, is a Buddhist idea that is among the most difficult for Westerners to accept: the concept of anatman, or ‘no-self’. Let’s be clear: Buddhists do not claim that people do not exist. When the Dalai Lama flies to a symposium in Geneva or London, he obtains a ticket with the name ‘Tenzin Gyatso’, and his body occupies a seat. However, for Buddhists there is no self in the deeper sense that no one exists as a singular, permanent structure distinct and isolated in any meaningful way from the rest of the world. This is entirely in line with an evolutionary and ecological approach to our origins and our embeddedness in natural processes.

Each of us arises in conjunction with others, dependent on and inseparable from those others. Trying to locate an inviolate particle of selfhood within anyone (or indeed, in any living thing) is not like finding a solid pit inside an apricot. It is more like peeling an onion: we are layers within layers, with nothing at the centre. Or, like an eddy in a river, each of us can be identified and pointed to, but nonetheless, there isn’t any persistent ‘us’: just a constantly moving pattern of flow, with everyone composed entirely of non-self stuff, all of it passing through. For Buddhists and ecologists alike, we are all created from spare parts scavenged from the same cosmic junk-heap, from which ‘our’ component atoms and molecules are on temporary loan, and to which they will eventually be recycled.

So our existence is not a distinct and separable phenomenon. Genuine compassion, in the sense of suffering with, should be easy — in fact it is unavoidable — since no one is distinct from the recipient of his or her concern. The 19th-century conservationist John Muir glimpsed the same principle: ‘When we try to pick out anything by itself, we find it hitched to everything else in the universe.’ For ecologists, no less than for poets or Buddhists, it is the fundamental rule, whether you call it connectedness, inseparability or, in the language of science, food webs, trophic levels, and community interactions.

At one point in The Origin of Species, Charles Darwin speculated playfully that, by keeping cats, English spinsters made London a more pleasant and flower-full place. Here is his reasoning: cats, as everyone knows, eat mice. Mice, as fewer people realise, occasionally destroy the nests of bumblebees, which are typically dug into the ground. And bumblebees, of course, pollinate flowers. So more cats, fewer mice. Fewer mice, more bumblebees. More bumblebees, more flowers. Therefore: more English spinsters with cats means more flowers. No one has tested Darwin’s proposal. But these surprising interlinked chains of cause and effect are very familiar in ecological science, as they are in Buddhist metaphysics.

In a recent experimental example, a project was conceived to investigate the causes of periodic infestations of gypsy moths, an introduced pest from Europe that, about one year in 10, causes great damage to forests in eastern North America. Researchers at the Cary Institute of Ecosystem Studies in Millbrook, New York suspected that there might be a connection between these periodic gypsy moth outbreaks and the abundance of acorns, because of the intervention of white-footed deer mice, common rodents in eastern forests. Deer mouse numbers skyrocket following a good acorn crop, which happens about every two to five years. And white-footed deer mice don’t eat only acorns. They are also major predators on the pupae of gypsy moths. So, it seemed reasonable that in the immediate aftermath of a heavy acorn production there would be a large mouse population. This, in turn, would keep the gypsy moths in check. Similarly, following poor acorn years, there should be relatively few mice and therefore, relatively more gypsy moths.

The Dalai Lama (a self-proclaimed admirer of Western science) has recently confirmed that he no longer believes all that business about the world being flat with a giant mountain at its centre

During one summer of the study — after a very heavy acorn crop — mice were abundant in the study site, an upstate New York forest. The ecologists removed most of the mice from three patches of forest, each measuring about 2.7 hectares (no small task). They proceeded to compare the numbers of gypsy moth pupae in these experimental areas with similar forest plots from which mice had not been removed. Sure enough, fewer mice yielded more moths; 45 times more, in fact.

The next step was to simulate a bumper acorn year. With the help of a local troop of Girl Scouts, they scattered nearly four tons of acorns over the experimental, mouse-depleted plots — which rapidly refilled with mice. This demonstrated that more acorns do indeed mean more mice. Which is a good thing if we want to prevent gypsy moth outbreaks. But the story isn’t over yet.

White-footed deer mice are not only consumers of acorns and of gypsy moth larvae. They are also a major reservoir for the parasitic organism that causes Lyme disease — a tick that lives on mice in its larval stage, and on deer as an adult. More acorns didn’t only mean more mice. There were also higher numbers of deer, attracted by the acorns, which brought along their burden of adult ticks, which bred and bestowed their larvae upon the flourishing mice. Mice occupying acorn-enriched plots had about 40 per cent more tick larvae than did the denizens of normal, control forests.

Even the first set of causations in that 1998 study — more acorns, more mice, and fewer gypsy moths — is complex enough. But the web of interdependent causes is much more subtle when we add the disease vectors. What are the practical implications? Foresters might be tempted to try to distribute additional acorns, inhibiting gypsy moth outbreaks in order to improve lumber yields. But this might bring about Lyme disease epidemics: more mice mean fewer gypsy moths, but also more ticks. Alternatively, public health officials who want to reduce Lyme disease might look into various ways of chemically suppressing mast production, which might in turn bring about gypsy moth infestations. Finally, it’s possible that Lyme disease outbreaks might be correlated, oddly enough, with how many acorns are produced that year by the forest.

Everything, it seems, is connected; the Buddha would understand.

All the same, we shouldn’t assume that the parallels between Buddhism and ecology are too exact, with either one mapping readily and completely onto the other. For me — an unrepentantly atheist scientist — there are many aspects of Buddhist tradition that seem downright ridiculous.

High on the list of such absurdities are the phenomena of iddhi, supernatural events that are supposed to be generated by extremely skilful and committed meditation. They appear often in Buddhist texts, and I don’t believe a word of them. Higher meditators are claimed to possess various supernatural abilities, becoming invisible on demand, walking through walls, on water, through the air, hearing people and other beings very far away, mind-reading, recalling past lives, even possessing ‘divine eyes’ that permit them to see the arising and passing away of karma.

The Buddha himself, immediately after he was born, is said to have taken seven steps and announced that this was the last time he would be reborn. When he died, lying on his side between two sal trees, they immediately and miraculously burst into bloom, out of season. The Buddha made it clear that he was not a god and should not be worshipped as one, yet this is violated every day by millions of people who persist in giving his teachings all the trappings of rigidified religion.

Traditional Buddhist cosmology is very complex, and more than a little weird, with the world composed of 31 levels, the lowest being a kind of hell, followed in turn by animals, ghosts, titans, humans, five different tiers of lesser gods, 15 of higher gods, after which one encounters, in turn, ‘infinite space’, ‘infinite consciousness’, ‘nothingness’, and finally ‘neither perception nor non-perception’. The Dalai Lama (a self-proclaimed admirer of Western science) has recently admitted that he no longer believes all that business about the world being flat with a great mountain — Mount Meru — at its centre. I don’t know about the beliefs of other leading Buddhists in this regard.

Neither is ‘Buddhism’ a monolithic whole. Some argue that ‘real’ Buddhism should be based on the early teachings of the Pali canon. But this is quite different from the Buddhism whose vision is so similar to modern ecology. The historical Buddha seems to have been more concerned with ending human suffering and encouraging individual enlightenment than with promoting environmental sensitivity. Instead of revelling in connectedness, early Buddhist thought focused on the downside of being ‘misled’ in maya, the illusory sense of the material world’s importance.

Just as Tibetan Buddhists practise ‘sky burials’, returning the human body to the vultures, so too does ecology celebrate the decomposing elk in the forest

To be sure, the science of ecology is divided as well: ecology has a double meaning, being used to refer both to the quantitative science and to a broad sense of ethical responsibility towards a complex natural world.

Even so, there are many striking and subtle connections between Buddhist metaphysics and ethics on the one hand and an ecological orientation on the other. Modern Buddhism, especially as promoted and practised in the West, has undergone something of an intellectual makeover. It now places more emphasis on social and environmental responsibility than the Buddha or his immediate followers seem to have favoured — perhaps in part due to the influence of Zen.

What of the West’s own spiritual traditions? Dichotomous thinking is basic to Western thought, deriving, perhaps, from the Greek Platonic constructs of ideal versus real and intellect versus emotion. These dualities were a powerful influence on the Judeo-Christian world view: God vs creation, spirit vs flesh, sin vs redemption and — most important for our purposes — humanity vs nature.

Although most spiritual traditions have some sort of ethical responsibility to the natural world built into them (from Christian stewardship to shamanic identification), the unfortunate reality is that, for the Abrahamic religions in particular (Judaism, Christianity and Islam), separateness — of soul from body, individuals from each other, heaven from hell, human beings from the rest of the natural world, and so forth — is the primary operating assumption.

Ecology was traditionally defined as the study of the interrelations between organisms and their environments, which is still somewhat dualistic. Significantly, ecologists now modify this definition to emphasise the fundamental identity of subject and surroundings. We cannot separate the bison from the prairie or the spotted owl from its coniferous forest. Since any such distinction is arbitrary, the ecologist studies the bison-prairie, owl-forest unit. Food webs, such as those connecting mouse, acorn and gipsy moth, are not mere descriptions of who-eats-whom, but outlines of their very being. The Buddhist suggestion that an organism’s skin does not separate it from its environment but, rather, joins the two, could just as well have come from a ‘master’ of physiological ecology.

With dualism overcome and the world seen in its complicated, organic wholeness, it is absurd to consider any natural process as ‘wrong’. It is what it is. ‘A duck’s legs, though short, cannot be lengthened without dismay to the duck, and a crane’s legs, though long, cannot be shortened without misery to the crane.’ Western thinking has generally been more Procrustean, seeking to amputate, stretch, or otherwise deform the natural world to suit our desires: to make it beautiful, picturesque or charming. Just as Tibetan Buddhists practise ‘skyburials’ to return the elements of the human body to the vultures and, eventually, the earth in an unsentimental recognition of our physical reality, so too does ecology celebrate the decomposing elk in the forest. Along the way, ecologists have argued with land managers until they have eventually come to the (Buddhistic) realisation that decomposition, predation, even forest fire, all have a place in maintaining healthy ecosystems.

Even our traditional Western notions of cause-and-effect have been re-evaluated, with systems analysis and complex flow charts representing numerous inputs and a bewildering array of interconnections, a kind of ‘neural net’ writ large. Embedded in an ecological world view is a notion of things in flux (or, in Buddhism, ‘impermanence’ or anitya), which is especially convivial to an evolutionary perspective — the recycling of life, the profound and unexpected consequences of interdependence. In fact, there are elements in Buddhism that seem to prefigure the most recent view of ecological systems as changeable, dynamic and prone to disturbance yet also highly interconnected and resilient.

In reaching for ways to describe such complex systems, Buddhist tradition has created many metaphors and images. Take ‘Indra’s net’, a structure described in the Avatamsaka Sutra. The story goes that the emperor Indra had a net spun, or woven, perhaps for the amusement and entertainment of his daughter. In any event, the net was infinitely large, and contained a pure and perfect jewel at each intersection of threads. If you looked closely at any one of these jewels, you could see, reflected therein, all the other jewels (remember, the net is infinite). On the surface of each jewel, all the others are reflected; when you peer into any one, you see all the others reflecting all the other others, in turn. ‘To see a world in a grain of sand,’ as William Blake put it, ‘and a Heaven in a wild flower’.

Not surprisingly, verbal analysis, with its unavoidable linearity, is inadequate for ecologists just as it has long been disdained by Buddhist masters. Where the Buddhist master plays with poetic imagery, the ecological imagination turns to modelling and metaphors of its own.

Ecology is many things: a science, a world view, a cautionary tale. It can be nearly incomprehensible in its mathematical thickets, downright tedious in its verbal pomposity, theoretically abstruse yet dirty-under-the-fingernails practical, often ignored and derided although desperately needed as a voice for basic planetary hygiene and a practical corrective to human hubris. It has been called the ‘subversive science’, since it subverts our egocentric insistence on separateness, and with it, our inclination to ride roughshod over the rest of the natural world. Buddhism is no less subversive, its ecological implications in particular carrying the serious practitioner far beyond giddy adoration of the Dalai Lama, or a fascination with celebrity Buddhists such as Richard Gere.

To EM Forster’s celebrated injunction, ‘only connect’, Buddhists and ecologists would add that we are already connected. Our job is to recognise this connection, and to act accordingly, paying attention to our breadth and not just our breath. But the ecological implications of Buddhism — or the Buddhist implications of ecology — are not easy. They require stout-hearted action, not mere sentiment. Shortly after the First National Economic Development Plan was drafted in Thailand in 1961, the Bangkok government imprisoned monks for teaching santutthi (contentment with what one has), out of fear that this Buddhist ideal would interfere with short-sighted economic development. And of course it would, and did.

This is the point of spiritual-religious-ethical perspectives: they make demands upon us. Martyrdom is out of fashion these days, but when we think of the murder of ‘that low-born cleric’ Thomas Becket in the cathedral, or of Burmese monks resisting the junta in 2007, we might remember that toughness in the face of power is part of a principled worldview. When it comes to the interpenetration of Buddhism and ecological wisdom, the consequences of serious ‘practice’ might be less dire, although equally significant. Instead of losing a life, we just might expand ours.

Read the study linking acorns, gypsy moths and Lyme disease.