"Urban transport systems based on a combination of rail lines, bus lines, bicycle pathways, and pedestrian walkways offer the best of all possible worlds in providing mobility, low-cost transportation, and a healthy urban environment." –Lester R. Brown, Plan B 4.0: Mobilizing to Save Civilization.
Chapter 1. Entering a New World: Environment and Civilization
To understand our current environmental dilemma, it helps to look at earlier civilizations that also got into environmental trouble. Our early twenty-first century civilization is not the first to face the prospect of environmentally induced economic decline. The question is how we will respond.
As Jared Diamond points out in his book Collapse, some of the early societies that were in environmental trouble were able to change their ways in time to avoid decline and collapse. Six centuries ago, for example, Icelanders realized that overgrazing on their grass-covered highlands was leading to extensive soil loss from the inherently thin soils of the region. Rather than lose the grasslands and face economic decline, farmers joined together to determine how many sheep the highlands could sustain and then allocated quotas among themselves, thus preserving their grasslands. The Icelanders understood the consequences of overgrazing and reduced their sheep numbers to a level that could be sustained. Their wool production and woolen goods industry continue to thrive today. 22
Not all societies have fared as well as the Icelanders. The early Sumerian civilization of the fourth millennium bc had advanced far beyond any that had existed before. Its carefully engineered irrigation system gave rise to a highly productive agriculture, one that enabled farmers to produce a food surplus, supporting formation of the first cities. Managing Sumer’s irrigation system required a sophisticated social organization. The Sumerians had the first cities and the first written language, the cuneiform script. 23
By any measure it was an extraordinary civilization, but there was an environmental flaw in the design of its irrigation system, one that would eventually undermine its food supply. The water that backed up behind dams built across the Euphrates was diverted onto the land through a network of gravity-fed canals. As with most irrigation systems, some irrigation water percolated downward. In this region, where underground drainage was weak, this slowly raised the water table. As the water climbed to within inches of the surface, it began to evaporate into the atmosphere, leaving behind salt. Over time, the accumulation of salt on the soil surface lowered the land’s productivity. 24
As salt accumulated and wheat yields declined, the Sumerians shifted to barley, a more salt-tolerant plant. This postponed Sumer’s decline, but it was treating the symptoms, not the cause, of their falling crop yields. As salt concentrations continued to build, the yields of barley eventually declined also. The resultant shrinkage of the food supply undermined this once-great civilization. As land productivity declined, so did the civilization. 25
Archeologist Robert McC. Adams has studied the site of ancient Sumer on the central floodplain of the Euphrates River, an empty, desolate area now outside the frontiers of cultivation. He describes how the “tangled dunes, long disused canal levees, and the rubble-strewn mounds of former settlement contribute only low, featureless relief. Vegetation is sparse, and in many areas it is almost wholly absent....Yet at one time, here lay the core, the heartland, the oldest urban, literate civilization in the world.” 26
The New World counterpart to Sumer is the Mayan civilization that developed in the lowlands of what is now Guatemala. It flourished from ad 250 until its collapse around ad 900. Like the Sumerians, the Mayans had developed a sophisticated, highly productive agriculture, this one based on raised plots of earth surrounded by canals that supplied water. 27
As with Sumer, the Mayan demise was apparently linked to a failing food supply. For this New World civilization, it was deforestation and soil erosion that undermined agriculture. Changes in climate may also have played a role. Food shortages apparently triggered civil conflict among the various Mayan cities as they competed for something to eat. Today this region is covered by jungle, reclaimed by nature. 28
The Icelanders crossed a political tipping point that enabled them to come together and limit grazing before grassland deterioration reached the point of no return. The Sumerians and Mayans failed to do so. Time ran out.
Today, our successes and problems flow from the extraordinary growth in the world economy over the last century. The economy’s annual growth, once measured in billions of dollars, is now measured in the trillions. Indeed, just the growth in the output of goods and services in 2007 exceeded the total output of the world economy in 1900. 29
While the economy is growing exponentially, the earth’s natural capacities, such as its ability to supply fresh water, forest products, and seafood, have not increased. A team of scientists led by Mathis Wackernagel concluded in a 2002 study published by the U.S. National Academy of Sciences that humanity’s collective demands first surpassed the earth’s regenerative capacity around 1980. Today, global demands on natural systems exceed their sustainable yield capacity by an estimated 25 percent. This means we are meeting current demands by consuming the earth’s natural assets, setting the stage for decline and collapse. 30
In our modern high-tech civilization, it is easy to forget that the economy, indeed our existence, is wholly dependent on the earth’s natural systems and resources. We depend, for example, on the earth’s climate system for an environment hospitable to agriculture, on the hydrological cycle to provide us with fresh water, and on long-term geological processes to convert rocks into the soil that has made the earth such a biologically productive planet.
There are now so many of us placing such heavy demands on the earth that we are overwhelming its natural capacities to meet our needs. The earth’s forests are shrinking. Each year overgrazing converts vast areas of grassland into desert. The pumping of underground water exceeds natural recharge in countries containing half the world’s people, leaving many without adequate water as their wells go dry. 31
Each of us depends on the products and services provided by the earth’s ecosystems, ranging from forest to wetlands, from coral reefs to grasslands. Among the services these ecosystems provide are water purification, pollination, carbon sequestration, flood control, and soil conservation. A four-year study of the world’s ecosystems by 1,360 scientists, the Millennium Ecosystem Assessment, reported that 15 of 24 primary ecosystem services are being degraded or pushed beyond their limits. For example, three quarters of oceanic fisheries, a major source of protein in the human diet, are being fished at or beyond their limits, and many are headed toward collapse. 32
Tropical rainforests are another ecosystem under severe stress, including the vast Amazon rainforest. Thus far roughly 20 percent of the rainforest has been cleared either for cattle ranching or soybean farming. Another 22 percent has been weakened by logging and road building, letting sunlight reach the forest floor, drying it out, and turning it into kindling. When it reaches this point, the rainforest loses its resistance to fire and begins to burn when ignited by lightning strikes. 33
Scientists believe that if half the Amazon is cleared or weakened, this may be the tipping point, the threshold beyond which the rainforest cannot be saved. We will have crossed the tipping point, with consequences that will reverberate around the world. Amazonian ecologist Philip Fearnside says “with every tree that falls, we increase the probability that the tipping point will arrive.” Geoffrey Lean, summarizing the findings of a symposium on the Amazon in the Independent, says that the alternatives to a rainforest in the Amazon would be “dry savannah at best, desert at worst.” 34
Daniel Nepstad, an Amazon-based senior scientist from the Woods Hole Research Center, sees a future of “megafires” sweeping through the drying jungle. He notes that the carbon stored in the Amazon’s trees equals roughly 15 years of human-induced carbon emissions in the atmosphere. If we reach this tipping point we will have triggered yet another climate feedback, taken another step that could help seal our fate as a civilization. 35
The excessive pressures on a given resource typically begin in a few countries and then slowly spread to others. Nigeria and the Philippines, once net exporters of forest products, are now importers. Thailand, now largely deforested, has banned logging. So has China, which is turning to Siberia and to the few remaining forested countries in Southeast Asia, such as Myanmar and Papua New Guinea, for the logs it needs. 36
A similar situation exists with fisheries. At first only a few fisheries were under excessive pressure, mostly in the North Sea, off the east coast of North America, and off the coast of East Asia. Now with fishing fleets replete with factory processing ships and modern technologies, overfishing is the rule, not the exception. In the absence of intervention, the decline in scores of fisheries will culminate in collapse. Some, such as the cod fishery off the coast of Newfoundland and the Atlantic tuna fishery, may never recover. The Chilean sea bass fishery in the Southern Ocean and the sturgeon fishery in the Caspian Sea may also be approaching the point of no return. 37
As wells go dry, as grasslands are converted into desert, and as soils erode, people are forced to migrate elsewhere, either within their country or across national boundaries. As the earth’s natural capacities at the local level are exceeded, the declining economic possibilities generate a flow of environmental refugees.
While the continuing erosion of the economy’s environmental support systems has convinced environmentalists, natural scientists, and others of the need to restructure the global economy, many others are not yet convinced. What is happening in China may change their minds.
22. Jared Diamond, Collapse: How Societies Choose to Fail or Succeed (New York: Penguin Group, 2005).
23. Sandra Postel, Pillar of Sand (New York: W. W. Norton & Company, 1999), pp. 13–21.
26. Robert McC. Adams quoted in Joseph Tainter, The Collapse of Complex Societies (Cambridge, U.K.: Cambridge University Press, 1988), p. 1.
27. “Maya,” Encyclopedia Britannica, online encyclopedia, viewed 13 September 2007.
28. Guy Gugliotta, “The Maya: Glory and Ruin,” National Geographic, August 2007.
29. Maddison, op. cit. note 14; IMF, World Economic Outlook Database 2007, electronic database, at www.imf.org/external/pubs, updated April 2007.
30. Mathis Wackernagel et al., “Tracking the Ecological Overshoot of the Human Economy,” Proceedings of the National Academy of Sciences, vol. 99, no. 14 (9 July 2002), pp. 9,266–71; Global Footprint Network, WWF, and Zoological Society of London, Living Planet Report 2006 (Oakland, CA: Global Footprint Network, 2006), p. 14.
31. Brown, op. cit. note 11, pp.101–02; Peter H. Gleick et al., The World’s Water 2004–2005 (Washington, DC: Island Press, 2004), p. 88; U.N. Population Division, op. cit. note 10.
32. Millennium Ecosystem Assessment (MA), Ecosystems and Human Well-Being: Synthesis (Washington, DC: Island Press, 2005); MA, Ecosystems and Human Well-Being: Policy Responses (Washington, DC: Island Press, 2005), p. 180.
33. Geoffrey Lean, “A Disaster to Take Everyone’s Breath Away,” Independent (London), 24 July 2006; Daniel Nepstad, “Climate Change and the Forest,” Tomorrow’s Amazonia: Using and Abusing the World’s Last Great Forests (Washington, DC: The American Prospect, September 2007).
34. Lean, op. cit. note 33.
35. Ibid.; Nepstad, op. cit. note 33.
36. U.N. Food and Agriculture Organization (FAO), ForesSTAT, electronic database, at faostat.fao.org, updated 22 December 2006; Patrick B. Durst et al., Forests Out of Bounds: Impacts and Effectiveness of Logging Bans in Natural Forests in Asia-Pacific (Bangkok: FAO, Asia-Pacific Forestry Commission, 2001); Eckholm, op. cit. note 19; Andy White et al., China and the Global Market for Forest Products: Transforming Trade to Benefit Forests and Livelihood (Washington, DC: Forest Trends, March 2006), p. 12.
37. FAO, The State of World Fisheries and Aquaculture 2004 (Rome: 2004), pp. 24, 30–32; Ted Williams, “The Last Bluefin Hunt,” in Valerie Harms et al., The National Audubon Society Almanac of the Environment (New York: Grosset/Putnam, 1994), p. 18; Konstantin Volkov, “The Caviar Game Rules,” Reuters-IUCN Environmental Media Award winner, 2001; Camillo Catarci, World Markets and Industry of Selected Commercially-Exploited Aquatic Species (Rome: FAO, 2004).
Copyright © 2008 Earth Policy Institute