by DK
International cooperation
Two UN agencies—the World Meteorological Organization and the UN Environment Programme—established the Intergovernmental Panel on Climate Change (IPCC) in 1988 to assess the risk of human-induced climate change.
The IPCC continues to monitor climate change. In 1992, the Rio Earth Summit, a UN initiative, was unprecedented in both its size and the scope of its concerns. It was the first of a number of international gatherings seeking, with much success, to get global agreement on greenhouse emissions. International cooperation is now seen as key to saving Earth’s environment.
IN CONTEXT
KEY FIGURE
Francis Bacon (1561–1626)
BEFORE
c.9500 BCE The first agricultural crops are cultivated in the Middle East.
340s BCE The Greek philosopher Aristotle devises a “ladder of being” with man at the top.
15th century The “Age of Discovery” begins: Europeans set out to explore the world in search of new resources.
AFTER
c.1750 New technology such as the steam engine launches the Industrial Revolution, which begins in Britain.
1866 Gregor Mendel pioneers the science of genetics, breeding 22 varieties of peas.
1970s The first experiments in genetic engineering—the direct manipulation of DNA by humans—take place.
The Renaissance (“rebirth”) between the 14th and 17th centuries is primarily associated with the arts and culture that flourished across Europe as the Catholic Church’s authority began to be challenged. It was also a time of extraordinary scientific advances, which some saw as the beginnings of a “scientific revolution.” Discoveries in astronomy, physics, and medicine gave rise to the idea that science could tell humans everything about the universe, and that knowledge would make humans its masters. Many scientists of the era believed that humans had a privileged place in a universe created by God for humanity to inhabit. English philosopher and scientist Francis Bacon (1561–1626), a pioneer in the development of scientific method, reinforced this idea; the natural world, in his view, existed to provide for humans, and should be conquered and exploited.
Bacon’s view later became known as “Imperial Ecology”—the idea that humanity’s knowledge of science and technology should be used to gain dominance over the natural world. Imperial ecology became the predominant ideology throughout the Renaissance, the Enlightenment—an 18th century movement dedicated to the pursuit of knowledge—and later the Industrial Revolution of the 18th and 19th centuries.
Sir Francis Bacon sits for a portrait in parliamentary robes. Bacon had an illustrious political career; knighted in 1603, he served as Lord Chancellor of England from 1618 to 1621.
See also: Global warming • A holistic view of Earth • Pollution • Environmental ethics
IN CONTEXT
KEY FIGURE
Gilbert White (1720–93)
BEFORE
4th century BCE Diogenes, a Greek philosopher, advocates forgoing the comforts of civilization in favor of a life “in accord with nature.”
1773 American naturalist William Bartram starts his field studies of the wildlife of the southeast US, documented in his 1791 book, Travels.
AFTER
1949 American ecologist Aldo Leopold publishes A Sand County Almanac, exploring the idea of humans’ “land ethic,” or responsibilities toward nature.
1969 Friends of the Earth is founded in the US—initially as an antinuclear group—marking the beginning of the modern Green movement.
In the late 18th century, rapid advances in science and technology—particularly in Britain—led to widespread industrialization and urbanization as people sought to control and exploit the natural world. There were, however, many in Britain who still lived and worked on the land. Among the educated rural class, some had a fascination for both science and nature. From this group, a new generation of naturalists emerged, suggesting that humans should learn from their scientific studies to live in harmony with the natural world rather than attempt to dominate it.
Arcadian ideology
In 1789, rural parson and naturalist Gilbert White published his Natural History and Antiquities of Selborne, which became a seminal work in what was later called “Arcadian Ecology.” Educated at Oxford and a keen gardener and ornithologist, White closely observed the wildlife around his Hampshire village, and made meticulous notes from 1751 onward. The book was compiled from his correspondence about his findings with several like-minded naturalists, but it was more than simply a collection of data. White’s engaging and often poetic style sent a persuasive message; his work rejected the “imperial” idea of conquering nature, and instead encouraged a balance between humans and the natural world—like that of the Ancient Greeks’ mythical idyll of Arcadia, for which White’s approach was named.
“From reading White’s Selborne I took much pleasure in watching the habits of birds, and even made notes.”
Charles Darwin
See also: Romanticism, conservation, and ecology • Environmental ethics • The Green Movement • Halting climate change
IN CONTEXT
KEY FIGURE
Henry David Thoreau (1817–62)
BEFORE
1662 English diarist John Evelyn’s work Sylva, advocating forest conservation, is presented to the Royal Society.
1789 Gilbert White publishes his Natural History of Selborne, inspiring a reaction against “imperial ecology.”
AFTER
1872 A bill creating the first US national park, Yellowstone, is signed into law by President Ulysses S. Grant.
1892 In San Francisco, Scottish–American conservationist John Muir founds The Sierra Club.
1971 The UNESCO “Man and the Biosphere” project is launched.
In many ways, Romanticism—a new cultural movement that emerged towards the end of the 18th century—was a reaction to the scientific rationalism of the Enlightenment. As industrialization took hold in urban areas, writers, artists, and composers began increasingly to glorify the natural world. The now prosperous middle classes were particularly inspired by Romantic portrayals of nature, and took up leisure pursuits such as hiking and mountaineering. The Romantic movement even affected scientific attitudes to nature by inspiring interest in the nascent field of ecology and the environmental movement.
The wild world
A key figure in the Romanticization of nature was Henry David Thoreau, an American writer from Concord, Massachusetts. His book Walden (1854) described his time living in a cabin in the woods by Walden Pond. Thoreau advocated preserving nature not for its own sake, but as a necessary resource in sustaining human life and a kind of spiritual enrichment. While Thoreau’s “wilderness” was not far removed from modern life, his Romantic portrayal of the natural world significantly influenced the conservation movement in the US and helped inspire the National Parks system.
Thoreau’s simple hut at Walden Pond appeared on the title page of this 1875 edition of Walden. Thoreau claimed he went to the wilderness to be free of the obligations of city life.
See also: Global warming • A holistic view of Earth • Urban sprawl • The Green Movement
IN CONTEXT
KEY FIGURE
George Perkins Marsh (1801–82)
BEFORE
1824 Joseph Fourier, a French physicist, describes the greenhouse effect—later identified as a contributing factor in global warming.
1830s Scientists posit that the Dutch colonization of Mauritius in the 17th century caused the dodo to become extinct.
AFTER
1962 In the US, Rachel Carson’s Silent Spring describes the harmful effect of pesticides on the environment.
1971 Greenpeace is founded by American environmentalists.
1988 The Intergovernmental Panel on Climate Change (IPCC) is set up to assess the “risk of human-induced climate change.”
The widely held view that the natural world existed to be exploited by humankind saw a major
rebuttal in the form of the 19th-century environmental movement. Arguments against the “imperial” attitude to nature, which had prevailed since the dawn of global exploration in the late 15th century, began with naturalists such as Gilbert White, and were echoed in the sentiments of Romanticism. Such ideas tended to focus on the idealization of nature, rather than examining the harm done by human conquests of the natural world.
In contrast to the emotive Romantic responses to modernism, American polymath George Perkins Marsh took a close look at humans’ impact on the environment and suggested changes. Marsh was horrified by the destructive effects of human management of natural resources. In his book Man and Nature, Or, Physical Geography as Modified by Human Action (1864), he pointed in particular to the mass deforestation which had virtually desertified some areas of the US.
Marsh believed that people must be made aware of their destructive impact and find new ways of managing natural resources to preserve the natural equilibrium. An activist as well as writer, he helped establish the principle of protected areas, and inspired the idea of sustainable resource management that became a core element of the 19th-century environmental movement.
George Perkins Marsh in an engraving from 1882. As well as being an environmentalist, the Vermont native was also a skilled linguist, lawyer, congressman, and diplomat.
See also: Global warming • A plastic wasteland • Humankind’s dominance over nature • Environmental ethics
IN CONTEXT
KEY FIGURE
Werner von Siemens (1816–92)
BEFORE
2nd century BCE The first water wheels mark a labor-saving turning point in the history of technology.
1839 French physicist Edmond Becquerel creates the first photovoltaic cell, using light to produce a weak voltage.
1873 French inventor Augustin Mouchot warns that fossil fuels will run out in the future.
1879 The first hydroelectric power plant is built at Niagara Falls in the United States.
AFTER
1951 Construction of the first grid-connected nuclear power plant begins at Obninsk in the USSR. It produced electricity from 1954 to 1959.
1954 Bell Laboratories in the US develop the first practical silicon photovoltaic cell.
1956 American geologist Marion King Hubbert predicts declining oil production after the year 2000.
1966 The world’s first tidal power station starts operating on the Rance River in France.
2018 The International Energy Agency predicts that the share of renewables in meeting global energy demands will increase by a fifth to reach 12.4 percent in 2023.
By the late 19th century, fears were already growing in industrial Europe that the world could not rely on fossil fuels forever. When the first working selenium solar cell panel was built in 1883 by American inventor Charles Fritts, the progressive German industrialist Werner von Siemens immediately recognized its huge potential for renewable energy. He declared: “the supply of solar energy is both without limit and without cost.” Yet, because no one at the time understood exactly how selenium created photoelectricity, and Siemens’s calls for more experiments went unheeded, solar cells were not developed until the 1950s. Today, solar power is the fastest growing source of new energy and predicted to dominate future growth in renewables.
The Ivanpah solar plant in the Mojave Desert, California, generates enough concentrated solar power to serve more than 140,000 homes at peak hours of the day.
Renewables v. fossil fuels
Human civilizations have drawn on renewable energy for millennia—from burning firewood to harnessing the wind to propel sailing ships. Renewable sources such as sunlight or tidal power are not at all depleted by use. By contrast, fossil fuels—such as coal, oil, and gas—have taken thousands of years to form, and when exhausted, cannot be replaced. Natural gas is an abundant fossil fuel, but its extraction can cause environmental problems, such as earth tremors and water contamination. Nuclear power, although sustainable for a long period of time, is not considered renewable because its production requires a rare type of uranium ore.
Energy sources such as solar power, wind, and water are also generally “clean”—unlike fossil fuels, they produce zero or very low greenhouse gas emissions. However, not all renewables are clean. People have burned wood and animal dung for heat and light for hundreds of thousands of years. Trees can be replanted and animals produce more dung, so the practice is sustainable, but burning such fuels also emits carbon dioxide (CO2), which is one reason why, unlike other forms of renewable energy, they are not classed as “alternative” sources.
Renewable, clean energy will have huge long-term benefits for populations and ecosystems. It reduces pollution, mitigates against global climate change, builds sustainability, and increases the energy security of countries. If it can be provided cheaply enough, it will also pull many people out of poverty. In some 30 countries, renewable energy now makes up more than 20 percent of the supply.
Solar energy
The Sun’s power could supply the world’s energy needs several times over. The International Energy Agency (IEA) believes that—in the short term—it has the greatest potential of all the renewables. Its radiation can be converted directly into electricity via photovoltaic cells (as with solar panels on buildings) or indirectly by using lenses or mirrors to create heat, which can be converted to electricity. This is called concentrated solar power.
Solar panels on a roof can heat domestic water. Sunlight can be employed to desalinate water through an evaporative process, first adopted by 16th-century Arab alchemists and used on an industrial scale in Chile in the late 19th century. In the developing world, solar disinfection is bringing safe drinking water to more than two million people; the process involves using solar heat and ultra-violet light to kill pathogens.
Wind power
For more than 2,000 years, people have built windmills to pump water and grind grain. Today, wind farms onshore and offshore account for around 9 percent of renewable energy consumption. A wind turbine’s huge blades turn around a rotor attached to a main shaft, which spins a generator to produce electricity. Wind power is now the leading area of energy growth in Europe, the US, and Canada. Almost 50 percent of Denmark’s energy comes from the wind, and in Ireland, Portugal, and Spain the figure is 20 percent. Its global potential is thought to be around five times its present level.
It is only economic to build wind farms where there is regular wind, however, so the potential is not evenly spread around the globe. Offshore wind is generally stronger and more regular than onshore. Floating turbines can generate wind energy far offshore, unlike seabed-anchored wind turbines, which have to be sited in shallow water close to the coastline.
Artificial photosynthesis
This solar fuel generator mimics the way plants turn sunlight and carbon dioxide in the air into energy and oxygen.
Since the early 1970s, scientists have been working to develop the technology to mimic the process of photosynthesis and create liquid fuels from carbon dioxide, water, and sunlight. All three are plentiful, so if the process can be replicated it could produce an endless, relatively inexpensive supply of clean fuel and electricity.
There are two crucial steps: to develop catalysts that use solar energy to split water into oxygen and hydrogen, and to create other catalysts that convert hydrogen and carbon dioxide into an energy-dense fuel, such as liquid hydrogen, ethanol, or methanol. Scientists at Harvard University recently used catalysts to split water into oxygen and hydrogen, then fed the hydrogen, plus carbon dioxide, to bacteria. The bioengineeered bacteria converted the carbon dioxide and hydrogen into liquid fuels. The next challenge is to transfer a successful lab experiment into something commercially viable.
Geothermal energy
The heat in Earth’s interior is derived both from the original formation of the planet and from the radioactive decay of materials within it. People have bathed in hot pools, where geothermally heated water reaches the surface
, since Paleolithic times. Ancient Romans made use of it to heat their villas. Today it is employed to generate electricity in at least 27 different countries, with the United States, the Philippines, and Indonesia the world’s leading producers.
Geothermal heat is also utilized directly to heat homes and roads in Iceland. Technology is now being developed that will use geothermal hot water to operate desalination plants. The only drawback of this renewable energy source is that it is concentrated near tectonic plate boundaries, where Earth’s mantle heat rises close to the surface. The potential is much greater, but drilling for deep resources is very expensive.
“… the wind and the sun and the earth itself provide fuel that is free, in amounts that are effectively limitless.”
Al Gore
American environmentalist and former US Vice President
Water power
Since water is 800 times denser than air, even a slow-moving flow can yield considerable amounts of energy if harnessed, for instance, by dams or tidal barrages that drive turbines connected to generators. China is the biggest producer of hydroelectric power (HEP), with 45,000 small installations in addition to “big-dam” schemes such as the Three Gorges project, whose 32 giant turbines have the capacity to produce 22,500 megawatts of electricity. A downside of big HEP schemes is that reservoirs created upstream of the dam can flood good farmland, forcing people to relocate and destroying ecosystems. Despite this, the IEA has estimated that by 2023, hydropower will be meeting 16 percent of the global demand for electricity.