Читать книгу Harmony: A New Way of Looking at Our World - Tony Juniper - Страница 13

While it is sometimes hard to comprehend the scale of the impact we have had on the Earth, the picture pieced together by the meticulous work of thousands of scientists tells an increasingly worrying story. Many in conservation circles believe that a sixth great extinction event is under way – a situation that might soon lead to a tsunami of species loss. This is not least because the rate at which species are being lost is now estimated to be between 100 and 1,000 times the natural background rate at which species disappear. Different kinds of animals and plants have always disappeared, but at the current high rates some projections suggest that by the end of this century we could lose up to 50 per cent of the total number of species that now inhabit the Earth.

Of course, during the long period that life has existed in abundance on Earth there have been times of rapid change. Indeed, etched into the fossil record are five periods when a large-scale loss of animal and plant species occurred – the last was when the dinosaurs disappeared, about 65 million years ago, marking a sharp boundary in the geological record between one epoch and another. Many believe the world recently entered a new one. And this one marks the fact that for the first time in the history of the Earth a single species has become the most dominant ecological agent – it is we humans, and that is why the period is called the Anthropocene. We are now the main reason for the rapid erosion of natural diversity, and whether we like it or not, this great living powerhouse is what sustains our well-being. We deplete and degrade it at our peril. In the pages that follow I will set out some of the reasons why this is the case, but for now it is enough to say that one reason why we are losing natural diversity so quickly is the rapid increase in our numbers.

Amphibian species are being lost at a terrifying rate. Fortunately the strawberry poison-dart frog remains common throughout its Central American range.

In 1900 the world population was about 1.6 billion. By the time I was born in 1948 it stood at 2.6 billion people. By the end of the twentieth century it had reached over six billion – marking a near fourfold increase in 100 years. In 2010 it will have exceeded 6.8 billion and is expected to continue climbing inexorably to about nine billion by 2050. While our numbers rise, and as we become richer and thus demand and expect more, the ability of our planet to meet our needs has significantly decreased. We are using up its natural capital and resources as if they were inexhaustible and without long-term value.

So far, as this has happened, food supply has managed to expand to keep up with demand. In part this has been achieved by ever more dependence upon intensive methods of farming, which we will explore later, and in part by the conversion of more and more land taken from Nature and put to agricultural use. Keeping pace with this demand has come at a terrible cost and unless we adopt some quite fundamental changes in expectation and practice, the cost is set to increase. Taking the world as a whole, in 1900 there were 7.91 hectares of land per person, whereas in 2002, owing to the increase in population and loss of land to urbanization, that figure had shrunk to 2.02 hectares. In 2050 it is expected that there will be about 1.63 hectares each – and from that ever smaller plot of land we will demand more and more.

Much of the world’s farmland is already virtually devoid of once native species of animals and plants, as modern high-tech agriculture has now basically turned farming into an arms race against Nature, excluding everything from the land except the highly bred crops designed to be resistant to powerful pesticides and grown using industrial production methods. These farming practices have a profound impact on the health – indeed existence – of the natural wildlife in the fields: the animals, plants, birds, the insects, microbes and bacteria that provide the services that sustain life. You don’t have to conduct major scientific studies to see that this is so. Watch the plough as it is pulled through the soil in the fields of many modern industrialized farms and notice how few birds follow the tractor. The great clouds of birds that were once the normal entourage of the plough were only ever there for the worms: and with fewer worms and other invertebrates in the soil, there are fewer birds. Some soils have lost their ability to restore fertility naturally and have become little more than a media for growth through the application of chemicals. The process not only continues but intensifies, with the use of ever more sophisticated chemicals and now genetic manipulation too.

The prairies of North America are a dramatic example. The land there was transformed in a very short time indeed and on a continental scale. Some 75 per cent of the United States’ original mixed-grass prairie has disappeared, much of it ploughed for the production of vast fields of maize, soya beans and wheat. This ‘thin-skinned’ land is now rendered at least temporarily productive with chemicals and machines, but in the opinion of many it should not be ploughed on such a scale. Its natural conditions render it vulnerable to collapse, which is what happened over large areas in the 1930s, when dustbowl conditions became one of the most potent images of the Great Depression. This situation arose through a combination of drought and ploughing; conditions that many believe could soon very easily be repeated – or exceeded – because of the effects of global warming.

LEFT: Soybean harvest, Brazil. Ever more intensive methods have increased yields. In 2010 Brazil and Argentina, the two biggest exporters after the US, increased soybean production by about a third. Industrial farming methods cause major environmental impacts, however, ranging from increased greenhouse gas emissions to largescale deforestation and from water pollution to biodiversity loss.

It was the excessive exploitation of the land, natural resources and animals of North America that caused Aldo Leopold to observe in his 1953 book Round River: ‘The outstanding scientific discovery of the twentieth century is not television or radio, but rather the complexity of the land organism. Only those who know the most about it can appreciate how little we know about it. The last word in ignorance is the man who says of an animal or plant: “What good is it?” If the land mechanism as a whole is good, then every part is good, whether we understand it or not … who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering.’

Clearly European colonists did not understand the ‘land mechanism’ when it came to the prairies – or if they did they chose to ignore what they knew. Equipped with a philosophy of pioneering exploitation, they progressively plundered the land. In response to our attempts to keep pace with ever more demand for food, so the trend continues and, as a result, high up on Mauna Loa in Hawaii, scientists measuring changes to carbon dioxide levels are also finding other signs of global change.

Each year as China commences ploughing, so dust particles appear a while later at the mountain-top observatory – even though the fields and the monitoring equipment that is detecting the dust are thousands of miles apart. It is a sign of trouble. The dust indicates the loss of soil on a grand scale as a process of degradation and desertification unfolds in a manner that threatens real challenges for future food security. Top soil that is in many places just a few inches deep is perhaps our most precious resource, and yet, because of how we farm, vast areas of soil are being degraded or lost. Dust storms are more and more common in China, with some dust travelling to Korea and Japan as well as over the Pacific. According to the United Nations some 400 million Chinese live in areas threatened with desertification. Farming, grazing, deforestation, and irrigation methods have all helped to create giant dunes up to 400 metres high. Each year these shift inexorably forward, swallowing everything in their path.

It is not only soil that is increasingly on the move: so is our food. As a result of ever more globalized trade, food travels further and further, often covering vast distances between continents, even food that could be produced locally. In fact it has got to the point now where some countries effectively import huge areas of land, in the sense that farms in distant countries produce only food that will be consumed elsewhere. This adds to the threat posed to some countries’ food security as land is moved from small-scale production for local markets to large-scale monoculture production to meet international demand. In the short term, countries might hope to earn revenue from these exports, but the costs of that policy can include serious social and economic problems, for example as water and land are driven into short supply and as food production for local consumption is reduced.

Giant sequoias at Kings Canyon National Park. The world’s largest tree species is confined to the western Sierra Nevada in California, USA. The tallest specimen alive today tops more than 270 feet. The oldest giant sequoias are in excess of 3,500 years old. They were well established at the time Tutankhamun was Pharaoh in Egypt.

OVERLEAF: Farmers work on the rice terraces in Guiyang, Guizhou Province, China. This traditional method of farming on slopes helps to conserve both water and soil, making it a more sustainable form of food production.

In the UK, our food in total travels an amazing eighteen billion miles each year. This includes imports by ships, trucks and planes. This produces an estimated nineteen million tonnes of carbon dioxide every year. Over two million tonnes of it is produced simply by cars travelling to and from shops. The majority of produce in the US travels between 1,300 – 2,000 miles from farm to consumer.

Perhaps the central message we should draw from this juxtaposition of circumstances is the need to promote sustainable farming everywhere, not just for local reasons, but for global ones too. Intensive monocultures destined for global commodity markets and dependent upon vast amounts of petrochemicals is a style of farming which, according to a recent UN survey, has been a major factor in causing up to a third of the world’s farmable soil to be classified, to different degrees, as degraded – and that is in the past half–century alone. This is not a sustainable form of agriculture, and just so that we are clear, the dictionary definition of that word ‘sustainable’ is ‘to endure without failure’.

In the UK, our food in total travels an

amazing eighteen billion miles each year. The

majority of produce in the US travels between

1,300 – 2,000 miles from farm to customer.

A truly durable farming system – one that has kept things going for 10,000 years – is the one that is commonly called ‘organic farming’. In a sense this is an unfortunate term because it has the ring of an alternative approach, or even a new one, when it is actually how farming was always conducted before industrial techniques came to dominate agriculture. It means farming in a way that preserves the long-term health of the soil, which comes down to giving back to Nature organic matter to replace what has been taken out. It means maintaining microbes and invertebrates in the soil and good moisture. It means using good water catchment management, planting trees that prevent the soil being eroded and maintaining the teeming biodiversity, including the beneficial and essential insects, such as bees.

It has become ever more apparent to me that the ‘food miles’, the degradation of soils, the chemical pollution and the massive consumption of oil and natural gas add up to a way of producing food that acts without any concern for the harmony found in Nature and the natural order. This approach abandons the fundamentals that should sustain food production. But it is the increasing demand for land that poses the biggest challenge.

I should be clear, though, that this is not in my view merely a competition between technological approaches and different methods of farming. Once again it comes down to that fundamental question we will address in the following chapters of how we have been persuaded to look at the world and regard our place within the great scheme of Nature. Looking at the way we treat the natural world and produce our food raises questions far deeper than those of how it will be possible to save charismatic birds like albatrosses or to grow food without destroying the land.