Environmental Issues

Environments in Middle and South America have long inspired concern about the use and misuse of the Earth’s resources. Millennia before Europeans arrived in this region, human settlements in the Americas had major environmental impacts. However, today’s impacts are particularly severe because both population density and per capita consumption have increased so dramatically. Moreover, local environments now supply global demands.

Tropical Forests, Climate Change, and Globalization

A period of rapid deforestation that has had global repercussions began in the 1970s in Brazil with the construction of the Trans-Amazon Highway. Migrant farmers followed the new road into the rain forest. They began clearing terrain to grow crops, prompting a few observers to warn of an impending crisis of deforestation. Initially, concern focused on the loss of plant and animal species, as the rain forests of the Amazon Basin are some of the most biodiverse on the planet. (Please note that the Amazon includes parts of Colombia, Peru, Bolivia, and Brazil; see Figure 3.1.) However, climate change now dominates concerns about deforestation in the Amazon and the rest of this region. As explained in Chapter 1 (see page 42), forests release oxygen and absorb carbon dioxide (CO₂), the greenhouse gas most responsible for global warming. The loss of large forests, such as those in the Amazon Basin, contributes to global warming by releasing CO₂ once locked in the woody bodies of trees. This CO₂ release happens as trees are burned to make way for crops and roads. When there are fewer trees, less CO₂ can be absorbed from the atmosphere. Together, all of the Earth’s tropical rain forests absorb about 18 percent of the CO₂ added to the atmosphere yearly by human activity. Because 50 percent of the Earth’s remaining tropical rain forests are in South America, keeping these forests intact is crucial to controlling climate change.

Middle and South American rain forests are being diminished by multiple human impacts (Figure 3.8). One of the biggest impacts is caused by the clearing of land to raise cattle and grow crops such as soybeans (for animal feed), sugarcane (for ethanol), and African oil palm (for cooking oil) (see Figures 3.8C and 3.8E). Brazil now ranks as the world’s fourth-largest emitter of greenhouse gases, after the United States, China, and Indonesia. In the Amazon, Middle America, and elsewhere in the region, forests are cleared to create pastures for beef cattle, many of which are destined for the U.S. fast-food industry. If deforestation continues in Middle America at the present rates, the natural forest cover will be entirely gone in 20 years.

FIGURE 3.8 Photo Essay: Human Impacts on the Biosphere in Middle and South America While there are a wide variety of human impacts on the environments of this region, here we focus on the processes of land cover and land use change that lead to the conversion of forests to grazing land or farmland. The forces guiding this process are complex, driven by poor people’s need for livelihoods, governments’ desire to assert control over lightly populated areas, and the demands for wood, meat, and food that arise in distant urban centers and the global market. Together these forces have led to a rapid loss of forest cover throughout much of this region. Brazil loses more forest cover each year than does any other country on the planet. 3.8a Courtesy Wesley Bocxe/Photo Researchers/Getty Images, 3.8b Courtesy Michael Fairchild/Peter Arnold/Getty Images, 3.8c Courtesy Glowimages/Getty Images, 3.8d Courtesy Michael Nichols/National Geographic/Getty Images, 3.8e Courtesy JC Patricio/Flickr Open/Getty Images

Hardwood logging and the extraction of underlying minerals, including oil, gas, and precious stones, are also contributing to deforestation. Investment capital comes from Asian multinational companies that have turned to the Amazon forests after having logged up to 50 percent of the tropical forests in Southeast Asia. Moreover, the construction of access roads to support these activities continues to accelerate deforestation by opening new forest areas to migrants. The governments of Peru, Ecuador, and Brazil encourage impoverished urban people to occupy cheap land along the newly built roads (see Figure 3.8A) and encourage deforestation by supplying chainsaws to the settlers. However, the settlers have a difficult time learning to cultivate the poor soils of the Amazon. After a few years of farming, they often abandon the land, now eroded and depleted of nutrients, and move on to new plots. Ranchers may then buy the worn-out land from these failed small farmers to use as cattle pastures (see Figure 3.8D).

While Middle and South America are significantly contributing to global warming by adding CO₂ to the Earth’s atmosphere, many people in this region are particularly vulnerable to the increasing threats of climate change. Figure 3.10 illustrates several such cases: shortages of clean water brought on by intensifying droughts and by glacial melting; vulnerability to rising sea levels; and the effects of increasingly violent storms.

Major international efforts are under way to combat climate change by preserving the world’s remaining forests, especially the crucial tropical rain forests found in this region. Integrating sustainable yet profitable agroforestry (tree cropping) into existing forests has been found to be among the cheapest ways to reduce greenhouse gas emissions. When well-funded and carefully executed, such efforts have the potential to save forests throughout the region. However, implementing complex agroforestry programs, which will require cooperation between diverse groups, will be an enormous challenge (see page 544 in Chapter 10).

Environmental Protection and Economic Development

In the past, governments in the region argued that economic development was so desperately needed that environmental regulations were an unaffordable luxury. Now, there are increasing attempts to embrace both economic development and environmental protection. One example of this new approach is ecotourism.

Ecotourism

Many countries are now trying to earn money from the beauty of still-intact natural environments through ecotourism. This form of tourism encourages visitors from wealthier areas to appreciate ecosystems and wildlife that do not exist where they live (Figure 3.9; see also On the Bright Side).

FIGURE 3.9 Ecotourism in the amazon. 3.9a Courtesy Michael Schwab/Flickr/Getty Images, 3.9b Courtesy Mark Carwardine/Peter Arnold/Getty Images, 3.9c Courtesy Inga Spence/Photolibrary/Getty Images

Ecotourism has its downsides, however. Mismanaged, it can be similar to other kinds of tourism that damage the environment and return little to the surrounding community. While the profits of ecotourism can potentially be used to benefit local communities and environments, the profit margins may be small.

The Water Crisis

Although Middle and South America receive more rainfall than any other world region and have three of the world’s six largest rivers (in volume), parts of the region are experiencing water crises (Figure 3.10). Most of the factors causing the water crises are induced by humans, who in turn are now exposed to a variety of water-related stresses. For example, the air pollution that hangs over so many cities in Middle and South America contributes to global warming, which in turn accelerates glacial melting in the Andes. The glaciers feed rivers that are the main source of water for millions (see Figure 3.10D). Should the glaciers actually disappear, the rivers will at best run only seasonally, devastating communities and industries that depend on them.

FIGURE 3.10 Photo Essay: Vulnerability to Climate Change in Middle and South America Adapting to the multiple stresses that climate change is bringing to this region is proving to be quite a challenge. Water-related troubles, such as drought, hurricanes, flooding, and glacial melting are combining with growing populations and persistent poverty to create a complex landscape of vulnerability to climate change. 3.10a Courtesy John Moore/Getty Images, 3.10b Courtesy Yuri Cortez/AFP/Getty Images, 3.10c Courtesy Thony Belizaire/AFP/Getty Images, 3.10d Courtesy John Coletti/AWL Images/Getty Images

Lax environmental policies allow industries to pollute both air and water with few restraints. Waterways along the Mexican border with the United States are polluted by numerous factories set up to take advantage of NAFTA-related trade with the United States and Canada (see discussion of maquiladoras). Only a small percentage of the often highly toxic water discharges are treated and disposed of properly. And in Mexico City, it is estimated that as much as 90 percent of urban wastewater goes untreated.

Rapid urbanization, combined with corruption, inadequate investment, and misguided policies, has left many people without access to clean water or sanitation. In some of the largest cities, the water infrastructure is so inadequate that as much as 50 percent of the fresh water is lost because of leaky pipes (see Figure 3.10A). Often as much as 80 percent of the population has no access to decent sanitation; toilets are sometimes entirely lacking, leaving people to relieve themselves on the city streets. This poses a major health hazard. Uncontrolled dumping of wastewater so pollutes local water resources that cities must bring in drinking water from distant areas.

Behind these immediate problems lie systemic policy failures and inadequate planning, such as that in Cochabamba, Bolivia (discussed in Chapter 1). There, efforts to improve the city’s inadequate water supply system focused on “marketizing” the water system. The water supply, long thought of as a public resource, was sold to a group of foreign corporations led by Bechtel of San Francisco, California. The hope was that Bechtel, in return for profits, would make investments in infrastructure that Cochabamba’s notoriously corrupt water utility would not make. Unfortunately, Bechtel, unfamiliar with the actual living conditions of the majority of citizens, immediately increased water prices to levels that few urban residents could afford, while doing little to improve water supply or delivery systems. At one point Bechtel even charged urban residents for water taken from their own wells and rainwater harvested off their roofs! Popular protests forced Bechtel to abandon Cochabamba’s water utility, which remains plagued by corruption and an inadequate infrastructure.