Mark Lynas - The God Species - How Humans Really Can Save the Planet...

However, it is not only predators that count. Bottom-up interference can also dramatically destabilise an ecosystem. In the early 1980s a new pathogen appeared in the Caribbean near the mouth of the Panama Canal, wiping out sea urchin populations with extraordinary virulence: within a year 98 per cent of the urchin population was gone, in what is still the worst recorded die-off of any marine animal in history. Because urchins are herbivorous grazers they perform an important function on reefs, keeping the corals clear of algae and seaweed that would otherwise choke the reef systems. Without them, the corals lacked protection, and within a year reefs from Jamaica to the coast of Venezuela disappeared under a thick layer of green slime. 42 Конец ознакомительного фрагмента. Текст предоставлен ООО «ЛитРес». Прочитайте эту книгу целиком, купив полную легальную версию на ЛитРес. Безопасно оплатить книгу можно банковской картой Visa, MasterCard, Maestro, со счета мобильного телефона, с платежного терминала, в салоне МТС или Связной, через PayPal, WebMoney, Яндекс.Деньги, QIWI Кошелек, бонусными картами или другим удобным Вам способом. After a decade, just 5–10 per cent of the original coral cover was left, 43 Конец ознакомительного фрагмента. Текст предоставлен ООО «ЛитРес». Прочитайте эту книгу целиком, купив полную легальную версию на ЛитРес. Безопасно оплатить книгу можно банковской картой Visa, MasterCard, Maestro, со счета мобильного телефона, с платежного терминала, в салоне МТС или Связной, через PayPal, WebMoney, Яндекс.Деньги, QIWI Кошелек, бонусными картами или другим удобным Вам способом. and little more remains to this day. 44 Конец ознакомительного фрагмента. Текст предоставлен ООО «ЛитРес». Прочитайте эту книгу целиком, купив полную легальную версию на ЛитРес. Безопасно оплатить книгу можно банковской картой Visa, MasterCard, Maestro, со счета мобильного телефона, с платежного терминала, в салоне МТС или Связной, через PayPal, WebMoney, Яндекс.Деньги, QIWI Кошелек, бонусными картами или другим удобным Вам способом. A whole marine ecosystem had irreversibly collapsed because of the removal of one of its key components.

Functioning ecosystems need not just a varied number of species, but also – just as crucially – habitat. Humans have disturbed, fragmented or ploughed up huge areas of the planet’s terrestrial surface. But there is a direct correlation between biodiversity and land area: the smaller the remaining fragment, the fewer species it can support. This so-called ‘species–area relationship’ was illustrated by a massive – though unintentional – field experiment beginning in 1986, when a gigantic hydroelectric dam was built in the jungles of Venezuela. When the lake behind the dam began to fill, the rising tide turned a hilly area of four thousand square kilometres into isolated islands, each with its tropical forest plant and animal species cut off by the surrounding waters. Some of the new islands were very small, just an acre or two in size, whilst others were relatively large, with areas of 150 hectares or more. As you might expect, the smallest islands lost the most biodiversity – three quarters of their original complement – due to their small areas. All islands, large and small, lost their top predators: the jaguar, puma and harpy eagle. But the species that did survive quickly became more abundant as both competition for food and predation ceased abruptly. Some islands were overrun by leaf-cutting ants. One, having housed a large herd of capybaras as the waters rose, ended up as little more than bare ground covered by capybara dung. On some islands, monkeys decimated bird populations, whilst on others rodent populations increased 35-fold. 45 Конец ознакомительного фрагмента. Текст предоставлен ООО «ЛитРес». Прочитайте эту книгу целиком, купив полную легальную версию на ЛитРес. Безопасно оплатить книгу можно банковской картой Visa, MasterCard, Maestro, со счета мобильного телефона, с платежного терминала, в салоне МТС или Связной, через PayPal, WebMoney, Яндекс.Деньги, QIWI Кошелек, бонусными картами или другим удобным Вам способом. In all cases, complex and formerly diverse ecosystems were torn apart and thrown into chaos.

From these and many other examples, ecologists now understand a fundamental principle of biodiversity: that the greater the diversity of species, the more resilient and stable an ecosystem can be. The same, of course, applies to the biosphere as a whole. We are only just beginning to realise all the myriad ways that different species act unconsciously together to keep this planet habitable and its climate tolerable. Might there be some kind of global ‘tipping point’ – like the ones that were passed in the Newfoundland cod fishery and the Caribbean coral reefs – where some kind of irreversible global ecosystem shift takes place? This is the possibility that the planetary boundary on biodiversity is intended to prevent: it is now absolutely clear that the Earth’s living biosphere depends fundamentally on the maintenance of a broad level of species diversity. If the Sixth Mass Extinction is allowed to continue – or still worse, accelerate further – then the chance of a global-scale ecosystem collapse can only continue to grow. the price of pandas

The current crisis in biodiversity tells us loud and clear that conventional approaches to conservation have failed. ‘Paper parks’ – named but barely protected – in developing countries are routinely violated by poachers and loggers. What areas are set aside for nature reserves are too small and too fragmented. At sea fishermen compete with each other in a global race to the bottom, knowing that if they do not catch the last bluefin tuna, someone else will. No wonder the 2010 Global Biodiversity Outlook report is full of ominous words and phrases like ‘serious declines’, ‘extensive fragmentation and degradation’, ‘overexploitation’ and ‘dangerous impacts’. To meet the planetary boundary, we need to make urgent changes in policy.

Biodiversity loss is fundamentally an enormous market failure, because the people that profit from destroying biodiversity are not generally the same people who lose out when the rainforests, mangroves and coral reefs are finally gone. When palm-oil companies move into the last remnants of rainforest in Borneo, the biofuels they sell deliver benefits to shareholders and foreign consumers, but local people are the losers, as are all the rest of us because of the destructive impact on the world’s climate and ecosystems. Our chief task today is to design systems that value nature in a direct and marketable sense and deliver hard cash to those who are in a position to protect ecosystems in a reasonably intact state. What is needed is not more moralising, but more money.