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flying blind to the brink of extinction
BOOK FEATURE:Posted: 11 Dec 2006
Flying blind to the brink of extinction
by George McGavin
'Ultimately it is human population growth and increasing consumption that drives every aspect of environmental degradation' says Dr George McGavin of Oxford's Natural History Museum, in a beautifully illustrated new book Endangered: Wildlife on the Brink of Extinction now in the shops. In the final chapter, reproduced here by arrangement with the publishers, the author asks the question 'What next?
The need for more and more agricultural and urban land leads to the loss of biodiversity and the overexploitation of natural resources. The idea that growth can be sustainable is nonsense. When resources are finite, any growth, however small, will ultimately become unsustainable.
Environmental problems such as salination through excessive irrigation, desertification and overconsumption has caused the collapse of numerous civilizations in the past. In some cases, emigration from the despoiled area to a new land flowing with �milk and honey� was possible; in others, humans degenerated into internecine war and perished.
The number of humans is predicted to rise to around 9 billion by the year 2050. Without widespread changes to policy and patterns of consumption, living standards across the world will decline, and for some they will deteriorate disastrously. The difference in human lives around the planet is already very marked. Some live long and productive lives relatively free of disease, while others suffer hunger and disease and have a life expectancy of as little as 40 years.
We need to reduce what has become known as our ecological footprint � the total area of productive land required to support each and every one of us sustainably. It has been calculated that the amount of available productive land per person is around 1.7 hectares but the world average footprint is 2.8 hectares, meaning that there is already a demand that exceeds that which can be replenished. For humans living in the most developed countries the footprint is many times larger than that of people living in the least developed countries. If the whole of the world�s population were to attain the highest levels of consumption (that of the average US citizen), it is estimated that we would need three more Earths.
|The human's closest living relative is the chimpanzee. With a DNA that is 98.4 per cent the same as that of humans, they are closer even to us that they are to gorillas.
Imagine setting up a colony on another planet similar to Earth. What ecosystem �goods and services� would we need to bring along to ensure our survival?
We would need a range of animals and plants. But which ones would be essential and which ones might we do without? The plants and animals would need food and whatever they need to grow and reproduce. We would need fibres, oils and fuels. We would need water. And what about soil? A single gram of garden soil contains around 30,000 protozoans, 50,000 algal cells, 400,000 fungal cells and billions of bacteria. The interactions of large numbers of species are needed to produce stable ecosystems. But how do you put a value on their �work�?
|The British sub-species of the Large Copper butterfly has gone forever.
The two most precious commodities, on which all terrestrial life depends, are soil and water. Every year many billions of tonnes of soil are being lost and, in years to come, well over half of the world�s agricultural land may be degraded. For a natural resource that provides anchorage and nutrients for all plant life, ameliorates the effects of pollutants, purifies ground waters and recycles nutrients we seem to pay it scant attention. Around 97 per cent of all Earth�s water is salty. Of the remaining three per cent that is freshwater, most is locked up in the polar ice caps, deep in underground aquifers, wetlands or permafrost, in the atmosphere or already contained in the tissues of all living organisms.
The amount of freshwater in rivers and lakes that you could actually drink is less than 100,000 cubic kilometres, or less than half a per cent of all the freshwater that exists. Seven times more drinking water is needed now than one hundred years ago and in some parts of the world so much water is taken for agriculture that even large rivers can run completely dry before they reach the sea. As the population increases, the hunger and starvation already suffered by large numbers of the world�s humans will become more widespread with appalling consequences for the world�s wildlife.
Many nations in the developed world have set ambitious targets for air quality, water pollution and vehicle pollution but it is a sad truth that environmental aspirations rarely translate into positive results. At the turn of the Millennium, the European Environmental Agency examined the progress made across Europe since 1991 on 12 key environmental problems. Positive development in the state of the environment was found with respect to just one of the 12 problems � the ability to address technological and natural hazards. In seven of the 12 areas � including degradation of soil, loss of biodiversity, and climate change � matters had deteriorated. The sad truth is that environmental protection has always been a poor cousin to economic growth.
|A wandering albatross calls to its mate on South Georgia. Its nesting grounds are protected, but out at sea longline fisheries are killing countless birds.
Tipping the balance
We have not even completed the task of cataloguing Earth�s wonderful biodiversity. Even so, the sheer scale of our own success means that we will face the future with far fewer species. What is less certain is the effect this loss will have on the planet�s ecosystems. The Earth has, after all, recovered from several mass-extinction events and gone on to produce a myriad of species � including ourselves.
The truth is that we simply do not know how many species can be safely lost. In effect, we are all aboard a plane that is flying blind. Losing species has been likened to taking rivets from the plane at random. Many are redundant, and, so far, the plane has managed to stay in the air. But it is a situation that cannot continue forever. The challenge today is to stem the tide of species loss, before we, too, become endangered.
Dr George McGavin is Assistant Curator of Entomology in the Oxford University Museum of Natual History and Visiting Professor of Entomology at the University of Derby. A naturalist and explorer, he has also made his mark as a prolific author, scientific consultant and television presenter, including - most recently as presenter of Expedition Borneo for the BBC History Unit and Discovery Channel.
Endangered: Wildlife on the Brink of Extinction is published by Cassell Illustrated at �20 hardback.