The Great Acceleration

An Environmental History of the Anthropocene since 1945

J. R. McNeill, Peter Engelke

• Publisher: Belknap Press
• Year: 2016
• ISBN:
  9780674970748
• Topic: Histoire
• Subtopic: Histoire du monde

The Earth has entered a new age—the Anthropocene—in which humans are the most powerful influence on global ecology. Since the mid-twentieth century, the accelerating pace of energy use, greenhouse gas emissions, and population growth has thrust the planet into a massive uncontrolled experiment. The Great Acceleration explains its causes and consequences, highlighting the role of energy systems, as well as trends in climate change, urbanization, and environmentalism.More than any other factor, human dependence on fossil fuels inaugurated the Anthropocene. Before 1700, people used little in the way of fossil fuels, but over the next two hundred years coal became the most important energy source. When oil entered the picture, coal and oil soon accounted for seventy-five percent of human energy use. This allowed far more economic activity and produced a higher standard of living than people had ever known—but it created far more ecological disruption.We are now living in the Anthropocene. The period from 1945 to the present represents the most anomalous period in the history of humanity's relationship with the biosphere. Three-quarters of the carbon dioxide humans have contributed to the atmosphere has accumulated since World War II ended, and the number of people on Earth has nearly tripled. So far, humans have dramatically altered the planet's biogeochemical systems without consciously managing them. If we try to control these systems through geoengineering, we will inaugurate another stage of the Anthropocene. Where it might lead, no one can say for sure.

CHAPTER ONE

Energy and Population

Energy is a vexingly abstract concept. The word is derived from a term apparently invented by Aristotle to signify movement or work. Modern physicists have gotten only a bit further than the venerable Greek. They believe that energy exists in finite quantity in the Universe but in several different forms. Energy can be neither created nor destroyed, but it can be converted from one form to another. For instance, when you eat an apple, you convert chemical energy (the apple) into bodily heat, into muscular motion, and into other forms of chemical energy (your bones and tissues).¹

The Earth is awash in energy. Almost all comes from the Sun. For human purposes, the main forms of energy are heat, light, motion, and chemical energy. The Sun’s payload comes chiefly in the form of heat and light. A third of this is instantly reflected back into space, but most lingers for a while, warming land, sea, and air. A little of the light is absorbed by plants and converted into chemical energy through photosynthesis.

Every energy conversion results in some loss of useful energy. Plants on average manage to capture less than 1 percent of the energy delivered by the Sun. The rest is dissipated, mainly as heat. But what plants absorb is enough to grow, each year, about 110 billion tons of biomass in the sea and another 120 billion tons on land. Animals eat a small proportion of that, converting it into body heat, motion, and new tissues. And a small share of those new animal tissues is eaten by carnivores. At each of these trophic levels, well under 10 percent of available energy is successfully harvested. So the great majority of incoming energy is lost to no earthly purpose. But the Sun is so generous, there is still plenty to go around.

Until the harnessing of fire, our ancestors took part in this web of energy and life without being able to change it. The only energy available to them was what they could find to eat. Once armed with fire, probably more than 1.5 million years ago, our hominin ancestors could harvest more energy, both in the form of otherwise indigestible foods that cooking now rendered edible, and in the form of heat. Fire also helped them scavenge and hunt more efficiently, enhancing their access to chemical energy in the form of meat. This low-energy economy remained in place, with some modest changes, until agriculture began about ten thousand years ago.

Growing crops and raising animals allowed ancient farmers to harvest considerably more energy than their forebears could. Grain crops are the seeds of grasses such as rice, wheat, or maize, and are packed with energy (and protein). So, with farming, a given patch of land provided far more usable energy for human bodies than it could without farming, perhaps ten to one hundred times more. Big domesticated animals, although they needed huge quantities of feed, could convert the otherwise nearly useless vegetation of steppe, savanna, or swampland into usable energy, helpful for pulling plows (oxen, water buffalo) or for transport (horses, camels). Farming slowly became widespread, although never universal.

Eventually, watermills and windmills added a little more to the sum of energy available for human purposes. Watermills might be two thousand years old and windmills one thousand. In suitable locations, where water flowed reliably or reasonably steady winds blew, these devices could do the work of several people. But in most places, wind and flowing water were either too rare or too erratic. So the energy regime remained organic, based on human and animal muscle for mechanical power, and on wood and other biomass for heat. The organic energy regime lasted until the eighteenth century.

Then in late eighteenth-century England the harnessing of coal exploded the constraints of the organic energy regime. With fossil fuels, humankind gained access to eons of frozen sunshine—maybe 500 million years’ worth of prior photosynthesis. Early efforts to exploit this subsidy from the deep past were inefficient. Early steam engines, in converting chemical energy into heat and then into motion, wasted 99 percent of the energy fed into them. But incremental improvements led to machines that by the 1950s wasted far less energy than did photosynthesis or carnivory. In this sense, culture had improved upon nature.

The enormous expansion of energy use in recent decades beggars the imagination. By about 1870 we used more fossil fuel energy each year than the annual global production from all photosynthesis. Our species has probably used more energy since 1920 than in all of prior human history. In the half century before 1950, global energy use slightly more than doubled. Then in the next half century, it quintupled from the 1950s level. The energy crisis of the 1970s—two sharp oil price hikes in 1973 and 1979—slowed but did not stop this dizzying climb in the use of fossil sunshine. Since 1950 we have burned around 50 million to 150 million years’ worth of it.

The fossil fuel energy regime contained several phases. Coal outstripped biomass to become the world’s primary fuel by about 1890. King coal reigned for about seventy-five years, before ceding the throne to oil in about 1965. Lately natural gas has grown in importance, so that in 2013 the world’s energy mix looked as shown in Table 1.

These data do not include biomass, for which figures are sketchy. But the best guess is that it accounts for perhaps 15 percent of the grand total, fossil fuels for about 75 percent, and hydroelectricity and nuclear power together for about 10 percent. King oil’s reign, now fifty years in duration, will likely prove as brief as coal’s, but that remains to be seen. We have used about one trillion barrels of oil since commercial production began around 1860, and now use about 32 billion barrels yearly.²

The global totals belie tremendous variation in energy use around the world. In the early twenty-first century, the average North American used about seventy times as much energy as the average Mozambican. The figures since 1965, in Table 2, speak volumes about the rise of China and India, and about the distribution of wealth within the world.

TABLE 1
Global commercial energy mix, 2013

Type of energy	%
Oil	33%
Coal	30%
Natural gas	24%
Hydroelectric	7%
Nuclear	4%
Data source: BP Statistical Review of World Energy, June 2014.

In 1960, most of the world outside of Europe and North America still used little energy. The energy-intensive way of life extended to perhaps one-fifth of the world’s population. But late in the twentieth century that pattern, in place since 1880 or so, changed quickly. In the fifty years after 1965, China increased its energy use by 16 times, India by 11, Egypt by 10 or 11. Meanwhile US energy use rose by about 40 percent. The United States accounted for a third of the world’s energy consumption in 1965, but only a fifth in 2009; China accounted for only 5 percent in 1965, but a fifth in 2009, and in 2010 surpassed the United States to become the world’s largest energy user.

In sum, the burgeoning rate of energy use in modern history makes our time wildly different from anything in the human past. The fact that for about a century after 1850 high energy use was confined to Europe and North America, and to a lesser extent to Japan, is the single most important reason behind the political and economic dominance these regions enjoyed in the international system. Since 1965 the total use of energy has continued to climb at only slightly diminished rates, but the great majority of the expansion has taken place outside of Europe and America, mainly in East Asia.

TABLE 2
Annual energy consumption, 1965–2013
(in millions of tons of oil equivalent)

Year	World	China	India	USA	Japan	Egypt
1965	3,813	182	53	1,284	149	8
1975	5,762	337	82	1,698	329	10
1985	7,150	533	133	1,763	368	28
1995	8,545	917	236	2,117	489	38
2005	10,565	1,429	362	2,342	520	62
2010	11,978	2,403	521	2,278	503	81
2013	12,730	2,852	595	2,266	474	87
Data source: BP Statistical Review of World Energy, June 2010, June 2012, 2014.
Note: Amounts are for commercial energy only, not biomass, which might add 10 to 15 percent.

Fossil Fuel Energy and the Environment

The creation and spread of fossil fuel society was the most environmentally consequential development of modern times. Part of the reason for that lies in the direct effects of the extraction, transport, and combustion of coal, oil, and (to a much lesser extent) natural gas. These were (and are) mainly a matter of air, water, and soil pollution. The other part resides in the indirect effects of cheap and abundant energy: it enabled many activities that otherwise would have been uneconomic and would not have happened, or perhaps would have happened but only much more slowly.

Extracting fossil energy from the crust of the Earth has always been a messy business. Coal, mined commercially in over seventy countries since 1945, had the most widespread impacts. Deep mining brought changes to land, air, and water. Carving galleries out from beneath the surface honeycombed the Earth in coal districts such as South Wales, the Ruhr, eastern Kentucky, the Donetsk Basin, and Shaanxi Province. Occasionally underground mines collapsed, as in the Saarland (Germany) in 2008, producing a small earthquake. In China, as of 2005, subsidence due to coal mines affected an area the size of Switzerland. Mine tailings and slag heaps disfigured the landscape around coal mines. In China (by 2005) coal mine slag covered an area the size of New Jersey or Israel. Everywhere tailings and slag leached sulfuric acid into local waters. In some Pennsylvania and Ohio waterways, acidic liquids from mine drainage had killed off aquatic life by the 1960s, although in some spots life has since returned. Deep mining also often put extra methane in the atmosphere, adding perhaps 3 to 6 percent on top of the natural releases of this potent greenhouse gas.

Deep mining has always put people in dangerous environments. In China, for example, where roughly one hundred thousand small mines opened up during the Great Leap Forward (1958–1961), mining accidents killed about six thousand men annually at that time, and at least that many yearly in the 1990s. In the United Kingd...