The Ecology Book

by DK

  When ozone levels continued to fall throughout the 1980s, opinion gradually changed. Consequently, in 1987, the Montreal Protocol for a global ban was agreed. The ozone layer is showing signs of recovery, and it is hoped that by 2075, stratospheric ozone will return to 1975 levels.

  CFCs

  Aerosol products such as insect repellents were widely available from the 1950s. The damaging effects of the CFCs they contained were not known until the 1970s.

  Chlorofluorocarbons (CFCs) are chemicals made up of carbon, chlorine, and fluorine atoms. They are non-toxic, nonflammable, and extremely stable. Their low reactivity makes them very useful, but is also the reason why they are so destructive. They can survive for over 100 years, which gives them time to diffuse into the stratosphere. There, they are broken down by the intense UV light to release chlorine, which reacts with ozone to form oxygen.

  CFCs were first produced in 1928, and were used as coolants for refrigerators. They were later used in a wide range of aerosol products, for example insect sprays, hair conditioners, and spray paints.

  The replacements for CFCs were hydrochlorofluorocarbons (HCFCs), which also deplete the ozone layer, although to a much lesser extent, and hydrofluorocarbons (HFCs). HCFCs will be phased out by 2020. HFCs do not harm the ozone layer at all—but they are very powerful greenhouse gases, and so in 2016 it was agreed that, from 2019, they too would be phased out.

  See also: Global warming • Environmental feedback loops • Pollution • The Keeling Curve • Environmental ethics

  IN CONTEXT

  KEY FIGURE

  Naomi Klein (1970–)

  BEFORE

  1972 The UN’s Conference on the Human Environment calls for an international approach to environmental protection.

  1980 The World Conservation Strategy, launched in 35 countries, introduces the concept of sustainability.

  1992 At the UN Earth Summit in Rio de Janeiro, member states produce “Agenda 21,” which outlines plans for managing resources in the 21st century.

  AFTER

  2015 The UN Sustainable Development Summit sets out 17 sustainable development goals and launches a bold global agenda, adopted by 193 member states.

  In This Changes Everything (2014), Naomi Klein railed against the way that governments and corporations deplete natural resources. “Ethical oil,” she maintains, is not just a contradiction in terms, “it’s an outrage.” A Canadian citizen, Klein has campaigned against the exploitation of the Athabasca tar sands, the largest of three major oil sand deposits in western Canada. The oil sand deposits lie under thousands of square miles of coniferous forests. The open-pit extraction of oil from tar sands is particularly harmful to the environment. Vast acres of forest are cleared, and ponds of pollutants are left behind. These can leak into the land, rivers, and groundwater, killing fish, migrating birds, and other animals.

  Extracting crude oil from Canada’s tar sands is notoriously harmful to the environment. It accounts for a tenth of Canada’s annual greenhouse gas emissions.

  Global action

  By the 1980s, the environmental effects of industrialization and depletion of the Earth’s resources were already becoming a matter of concern. The United Nations (UN) created a World Commission on Environment and Development, which published a report in 1987 called “Our Common Future.” Contributing experts, including scientists, agriculturalists, foreign ministers, technologists, and economists, made it clear that the future of humans relied on balancing ecology and economics in a way that was sustainable and fair for all nations around the world. Key areas in the struggle for a sustainably managed Earth are use of fossil fuels, deforestation, and water management.

  Five years later, at the 1992 Earth Summit in Rio de Janeiro, 172 nations signed environmental resolutions. Among them was Agenda 21, a plan for governments to work together to protect natural resources and the environment. However, implementing changes has proved difficult, and subsequent Earth summits have called for better international cooperation in order to achieve goals set.

  Peak oil

  Fossil fuels are among the world’s most highly prized resources. People have become increasingly reliant on oil, squandering it to create a lifestyle that is ultimately unsustainable. The oil crises of the 1970s highlighted how dependent industrialized nations were on an economically viable supply. With this came, too, the realization that oil is a finite resource. Scientists had already considered the problem and calculated the date when the supply of oil would peak, before it ran out or became uneconomical to extract. In 1974 the peak oil date was predicted to be 1995, with the caveat that there were several potential variables and unknowns such as consumption rates, available technology, and reserves yet to be discovered. In the early 21st century, new dates were given, some extending the timeline for oil to 2030 or beyond. In 2011, however, US environmentalist Bill McKibben declared that calculating a peak oil date was pointless; if all known oil reserves were burned, the carbon produced would be five times the amount required to heat the planet by 3.6°F (2°C)—the “safe” temperature limit that climatologists had worked out in 2009. The science has evolved, but the predicted risks of burning fossil fuels remain dire.

  NAOMI KLEIN

  Born in Montreal, Canada, in 1970 to politically active parents, Klein developed a sophisticated understanding of the way the world works while still young. Her first job was on a Toronto newspaper, The Globe and Mail. Her debut book No Logo, criticizing globalization and corporate greed, was a bestseller. Her second, The Shock Doctrine, attacked neoliberalism. Klein then began campaigning against corporate interests taking priority over the environment and the interests of humanity. Her book This Changes Everything was later made into a film. Klein’s many campaigns included a protest against the construction of the Keystone XL pipeline—a symbol in the battle against fossil fuel use and climate change. In November 2016, she was awarded Australia’s Sydney Peace Prize.

  Key works

  2000 No Logo

  2007 The Shock Doctrine: The Rise of Disaster Capitalism

  2014 This Changes Everything: Capitalism vs The Climate

  “… the conservation of natural resources is the fundamental problem. Unless we solve that problem it will avail us little to solve all others.”

  Theodore Roosevelt

  Saving trees

  Forests are a valuable natural asset that Earth cannot afford to lose. Their diminished numbers pose a significant threat for the climate; trees are “carbon sinks,” meaning they take in carbon dioxide and use it to fuel growth. This then prevents carbon from contributing to global warming. Trees are a renewable resource, and people, businesses, and nations often plant them to offset fossil fuel use, but not in sufficient numbers. According to Friends of the Earth, the annual loss of forests worldwide directly causes 15 percent of global greenhouse gas emissions.

  Rain forests, estimated to contain 50 percent of the world’s species, are particularly vulnerable to deforestation. Around 17 percent of the Amazon rain forest alone has been lost in the past 50 years. As “Our Common Future” suggested, part of the problem is that developing countries can earn money from large corporations if they clear rain forests for mining, logging, and cash crops. In Indonesia, for example, intensive deforestation took place to make way for palm oil plantations. Greenpeace reports that the amount of Indonesian rain forest logged, burned, or degraded in the last 50 years is equivalent in area to twice the size of Germany. The UN and other bodies now offer developing countries technical advice and financial incentives to manage their forests in a more sustainable way.

  Deteriorating soil

  Topsoil is perhaps one of the world’s most undervalued resources. This vast ecosystem, composed of animals, microbes, plant roots, and minerals, is a complex and delicate structure that is slow to form and easily lost. The World Wildlife Fund estimates that half of the world’s topsoil has been eroded by wind and rain in the last 150 years. Particles then collect in streams and rivers, clogging them w
ith sediment. Soil loss occurs due to overgrazing, removal of hedges, and use of agrochemicals that affect the soil structure. Measures such as resting the soil, terracing, dams, and strategic planting can help. In the village of Aamdanda in Nepal, for example, steep-sided slopes are stabilized with broom grass. The plant binds the soil; it is also a fodder crop and is used to make brooms, which the villagers sell.

  Thick forests like the one in this 15th-century painting by Italian artist Paolo Uccello are returning to Europe, where they have grown by 42 million acres (17 million ha) since the 1990s.

  Water pressures

  Clean drinking water is a limited resource. Water covers around 75 percent of Earth’s surface, but 97.5 percent of it is salt water. Of the remaining 2.5 percent, most is locked away in glaciers or in deep underground aquifers. Only one-hundredth of 1 percent of all the water in the world is readily available for human use. Drinking water is also not distributed equally, being naturally scarcer in hot, arid areas of the world than in temperate zones.

  Population pressures and wealth also have an impact on water supplies. The UN believes everyone should have access to at least 88 pints (50 liters) of freshwater a day, but people in sub-Saharan Africa manage on 21 pints (10 liters) a day, while the average American enjoys almost 740 pints (350 liters).

  Around the world, water sources are also being bought up by large corporations. Some scientists warn that, if our current usage patterns continue and population rates grow at their current rate, by 2030 global demand for clean water will exceed supply by 40 percent.

  Future plans

  New strategies are evidently required to save the world from human destruction. Transition engineering, an emerging multi-disciplinary field, may help. It aims to use existing businesses, organizations, and systems to find innovative ways to minimize environmental impacts and manage resources.

  Some progress is being made, in part thanks to campaigning by people like Naomi Klein. A number of European and Asian countries, including the UK, have decided to phase out fossil-fuel vehicles. In other areas, however, socio-economic and political problems remain obstacles to reform. As “Our Common Future” stated, meeting humanity’s goals and aspirations responsibly “will require the active support of us all.”

  “You have to think in terms of the survival of human society … it is not only the magnitude of change, it’s the pace at which it changes.”

  Benjamin Horton

  British geographer

  Easter Island

  Some 887 moai cover the slopes of Rano Raraku, Easter Island’s volcanic crater, the source of the stones from which the statues were carved.

  The fate of the ancient people of Easter Island illustrates the importance of managing natural resources. Once a thriving community of 12,000 people who erected enormous stone monuments, they had dwindled to just a couple of thousand by the time Europeans discovered the island in 1722.

  Mismanagement of a fragile ecosystem, especially mass deforestation, and warring between tribes, had been the cause of their demise. The giant heads, or moai, are made of stone, but logs were needed as rollers to transport them from the quarries to ceremonial sites. As the island’s many palms were cut down, there was no wood left for fishing canoes, which led to many people starving to death.

  The final tragedy came in 1862, with the arrival of slave traders, who captured 1,500 islanders and took them to Peru, where almost all of them died. The 15 islanders who eventually managed to make it home unwittingly introduced smallpox to the island. By 1877, only 111 inhabitants survived.

  See also: Deforestation • Overfishing • The water crisis • Humankind’s dominance over nature • Human devastation of Earth

  IN CONTEXT

  KEY FIGURE

  John Crosbie (1931–)

  BEFORE

  1946 The International Whaling Commission is set up to review and control whaling, reversing a dramatic decline after centuries of hunting.

  1972 Overfishing and a strong El Niño cause Peru’s coastal anchovy fisheries to crash—a blow to the national economy.

  AFTER

  2000 The World Wildlife Fund places cod on its endangered species list and launches a UK Oceans Recovery Campaign.

  2001 Jeremy Jackson and other marine biologists trace the history of overfishing.

  2010 The UNESCO Aichi Biodiversity Target 11 calls for a tenth of coastal and marine areas to be protected by 2020.

  In 1992, one piece of legislation changed the ecological, socioeconomic, and cultural structure of Canada’s Atlantic Maritime provinces. John Crosbie, the Federal Minister of Fisheries and Oceans, placed a moratorium on the Atlantic cod fishery; no further cod could be harvested from the ocean. His ruling was a necessity; the volume of northern cod was down to 1 percent of previous levels. The region had been overfished to the point where recovery could not occur if fishing were allowed to continue. Crosbie called it the toughest political moment of his career. The decision put thousands of Canadians out of jobs. For 500 years, the cod fishery had supported Maritime residents, particularly in Newfoundland.

  The 1992 moratorium was initially supposed to last only two years, but, with the stocks not yet recovered, it is still largely in place. From around 2005 to 2015, the volume of northern cod rose by about 30 percent each year along Newfoundland’s northeast coast, although stocks further south did not recover as fast. In 2017 and 2018, however, cod numbers declined sharply, and the overall stocks are still too low to support large-scale fishing. Climate change has contributed to the problem: higher temperatures have created conditions in which both the cod and its food sources struggle to survive. A further blow to Newfoundland’s fishermen—who largely turned to catching shrimp and crab—is that where cod numbers improved, cod began eating the shrimp. The ecosystem cannot support both a large-scale shrimp and crustacean industry, and large-scale cod fishing.

  A sustainable harvest

  The Newfoundland problem demonstrates the complexities of fishery management, which often relies on the concept of maximum sustainable yield: the volume of fish harvested from the sea should be equal to the volume replenished through reproduction. This is usually achieved through quotas, which limit the number of fish that can be brought in during a season. Quotas can curb unsustainable fishing: for example, 16 percent of fish stocks in American waters were overfished in 2015, down from 25 percent in 2000. However, the quota system can encourage fishermen to take the largest fish possible, and to throw back smaller fish, which frequently die from the stress of being caught. In many cases, quotas are also not set at a truly sustainable limit; commercial fishermen often have considerable lobbying power, and focus on the short-term economic gains of catching more fish rather than on long-term sustainability. Fishery management can be further complicated by factors such as the open access nature of the ocean, illegal fishing, and an absence of regulation and oversight.

  Marine reserves

  Bigeye trevallies are among the many species in the Malpelo Fauna and Flora Sanctuary, the biggest no-fishing zone in the Eastern Tropical Pacific, noted for its sharks.

  A promising tool for fish management is the creation of marine protected areas (MPAs), which legally protect fish stocks and ecosystems. MPAs cover around 3.5 percent of the world’s oceans, but only 1.6 percent of MPAs are the strongest “no-take zones” where fishing, extraction of materials, dumping, drilling, and dredging are banned. One meta-analysis of scientific studies showed that the volume of fish species is on average 670 percent greater in fully protected “no-take” marine reserves than in areas that have no protection, and 343 percent greater than in partially protected MPAs. No-take zones effectively preserve and restore damaged ecosystems, too; coral reefs in protected zones of the Pacific Line Islands recovered from an El Niño event within a decade, but those in unprotected areas did not. Some studies suggest that legally enforced reserves may even help replenish fisheries outside their borders.

  A worldwide crisis

  Overfishing i
s now a global issue, with more than 30 percent of the world’s fisheries harvested beyond their biological limits, and 90 percent of fish stocks currently at their limits or overfished. Sustainable management is now essential if fisheries are to continue to provide jobs and meet consumer demand.

  The management strategies adopted depend on the nature of the problem. If fish are being taken before they are mature, this will limit the stock’s future ability to reproduce at a maximum level and keep their numbers replenished. Placing minimum size limits on fish can help control this type of overfishing. If too many mature fish are being caught, this could leave too few to reproduce and replenish the present population. In this case, moratoriums and quotas are among measures that can help. Finally, ecosystem overfishing occurs when a fishery is so depleted that the ecosystem itself changes and is no longer able to support the fish stock at a sustainable level. It generally occurs when large predatory fish are overfished, allowing populations of smaller forage fish to increase and alter the entire ecosystem. This happened in the North Atlantic cod fishery: without the cod to keep them in check, the cod’s three main food sources—shrimp, crab and capelin fish—all increased in numbers.