Southeast Asia has the second-highest rate of deforestation of any world region, after sub-Saharan Africa. With only 5 percent of the world’s forests, Southeast Asia has accounted for nearly 25 percent of deforestation around the world in the last 10 years. The forces driving deforestation in Southeast Asia are global. Figure 10.8A, B and the figure map show the supply chain that takes wood from various tropical regions to Europe and Asia, where it is turned into furniture and other products. Figures 10.8C, D show who is importing and exporting sawn wood; Figure 10.8E lists the different activities for which the land is deforested legally. It is extremely difficult to know the extent of illegal deforestation. The World Wildlife Fund estimated that more than 40 percent of the timber production in 2006 in Indonesia was illegal.

The regional environmental impacts of deforestation and the agriculture that often follows it are addressed in Figure 10.9. One effect is that indigenous people of the forest lose their living space and resources when the land is given over to export agriculture. Another is the loss of habitat for orangutans, the Sumatran tiger, the Sumatran rhinoceros, and tens of thousands of other less well-known species that are displaced when rain forests are converted to agricultural uses. Finally, the emissions of greenhouse gases that accompany deforestation processes contribute to climate change. 222. INDONESIA’S POLLUTED ENVIRONMENT THREATENS HAWKSBILL TURTLE

Deforestation is a major contributor to global climate change because enormous amounts of carbon dioxide (CO₂) are released when forests are removed and the underbrush is burned. Fewer trees also mean that less CO₂ is absorbed from the atmosphere. Every day, 13 to 19 square miles (34 to 50 square kilometers) of Southeast Asia’s rain forests are destroyed, much of it done illegally. A great deal of this deforestation takes place in Malaysia and Indonesia, where the logging of tropical hardwoods for sale on the global market is a major activity (see Figure 10.8).

Significant amounts of CO₂ are also released when the forests are converted to oil palm plantations, especially when the forest is burned to clear the land for the plantations. For decades, these activities have made Indonesia among the world’s biggest contributors to global climate change. Since 1950, the tropical forest cover on the Indonesian part of the island of Borneo alone has decreased by about 60 percent. Oil palm plantations now constitute the predominant use of land there.

The Costs of Logging, Legal and Illegal Deforestation costs Southeast Asian countries billions of dollars per year in lost forest services, such as renewable food, construction material, and fuel resources; rainwater capture and purification; flood amelioration; biodiversity preservation; and CO₂ absorption. Government regulations that limit logging have been constrained by rampant corruption, but recent efforts to enforce limits may be yielding results. With a vision of sustainable logging as a long-term source of income for his country, Indonesian president Susilo Bambang Yudhoyono has lead the fight to reduce deforestation (see “On the Bright Side: Indonesia Tries to Slow Deforestation and Reduce Greenhouse Gas Emissions”).

Oil Palm Plantations Palm oil, which is used around the world in food products, as a cooking oil, in soaps and cosmetics, and as a machine oil, is at the center of debates over global climate change in Southeast Asia. The oil palm originated in West Africa and was brought to Southeast Asia early in the colonial era. Today, Indonesia and Malaysia are the world’s largest palm oil producers, and the expansion of their oil palm plantations has resulted in extensive deforestation. Much of the deforestation is in lowland peat swamps which, in a natural state, are capable of storing large amounts of carbon in their soils. To create space for oil palm plantations, the swamps are drained and most of their vegetation is burned (see Figure 10.9A). Often the fires spread underground to the peat beneath the forests, smoldering for years after the surface fires have been extinguished. These subsurface fires release enormous amounts of carbon into the atmosphere. In recent years, smoke from burning forests and peat has periodically covered much of the region, dramatically reducing air quality and even making it necessary for people in rural areas to wear masks.

Palm oil has been promoted as a potential solution to global climate change because it can be converted into fuel for automobiles. The claim is that because the palm trees absorb CO₂ from the atmosphere just as the original forest did, palm oil could be considered a “carbon neutral” fuel. This is a fallacy because palm trees do not absorb carbon at a rate equivalent to natural rain forests—and if forests are burned to clear land for plantations, it can take decades to offset the initial carbon emissions produced by deforestation. If a peat swamp is cleared for an oil palm plantation, more carbon is released through the burning of subsurface peat than centuries of CO₂ absorption by growing oil palms can counteract.

Food production contributes to global climate change in two ways. First, it is a major contributor to deforestation, and second, some types of cultivation actually produce significant green-house gases.

Shifting Cultivation Also known as slash-and-burn or swidden cultivation, shifting cultivation has been practiced sustainably for thousands of years in the hills and uplands of mainland Southeast Asia and in many parts of the islands (Figure 10.10 map). To maintain soil fertility in these warm, wet environments where nutrients are quickly lost to decay, traditional farmers move their fields every 3 years or so, letting old plots lie fallow for 15 years or more. The regrowth of forest on once-cleared fields not only regenerates the soil and inhibits runoff, it also absorbs significant amounts of CO₂ from the atmosphere. However, if fallow periods are shortened or are disrupted by logging, soil fertility can collapse, making future cultivation impossible. In some cases, fertility can be temporarily restored through the use of chemical or organic fertilizers, but these can be too expensive for most farmers and chemical fertilizers may be ineffective after a year or be too unhealthy for food cultivation. Tropical soils left bare of forest for too long eventually turn into hard, infertile, sunbaked clay called laterite.

Where population densities are relatively low, subsistence farmers can practice sustainable shifting cultivation indefinitely, but to allow for long fallow periods and still support human populations, this system requires larger areas than other types of agriculture. If population density increases, farmers are usually forced to shorten fallow periods, thus inhibiting forest regrowth and soil regeneration. Even though individual plots are small, the plots eventually become close to one other because shifting cultivation requires clearing forest at each move. Shifting cultivation now accounts for a significant portion of the region’s deforestation. Moreover, because burning usually clears the forests, shifting cultivation can result in wildfires. This is especially true during an El Niño period, when rainfall is low. These wildfires have increased in recent years, particularly in Indonesia, further contributing to deforestation and carbon emissions there.

Wet Rice Cultivation Another major contributor to global climate change is Southeast Asia’s most productive form of agriculture. Wet rice cultivation (sometimes called paddy rice) entails planting rice seedlings by hand in flooded and often terraced fields that are first cultivated with hand-guided plows pulled by water buffalo or tractors (see Figure 10.9D). Wet rice cultivation has transformed landscapes throughout Southeast Asia. It is practiced throughout this generally well-watered region, especially on rich volcanic soils and in places where rivers and streams bring a yearly supply of silt.

The flooding of rice fields also results in the production of methane, a powerful greenhouse gas responsible for about 20 percent of global climate change. It is estimated that up to one-third of the world’s methane is released from flooded rice fields, where organic matter in soil undergoes fermentation as oxygen supplies are cut off. Wet rice has been cultivated for thousands of years, but the increase in human population in the last 25 years has driven a 17 percent expansion of the area devoted to wet rice. The map in Figure 10.10 shows patterns of field and forest crops across the region.

Commercial Agriculture During the recent decades of relative prosperity, small farms once operated by families have been combined into large commercial farms owned by local or multinational corporations. These farms produce cash crops for export, such as rubber, palm oil, bananas, pineapples, tea, and rice (see Figure 10.10A and the figure map). Commercial farming on large tracts of deforested land reduces the need for labor by using mechanization, irrigation, and chemicals for fertilizer and pest control. The objectives of commercial farming are to generate big yields and quick profits, not to develop long-term sustainable agriculture. Many commercial farmers have achieved dramatic boosts in harvests (especially of rice) by using high-yield crop varieties, the result of green revolution research that has been applied in many parts of the world (see Chapter 8).

As we have noted in relation to other world regions, large-scale commercial farming has significant negative environmental effects, including the loss of wildlife habitat and hence the loss of biodiversity (see Figure 10.9B); increases in soil erosion, flooding, and chemical pollution; and depletion of groundwater resources. In addition, poor and subsistence farmers unable to afford the new technologies find they cannot compete with large commercial farms and are forced to migrate to cities to look for work.

Many of Southeast Asia’s potential vulnerabilities to global climate change are related to water resources. Four areas of vulnerability may affect the region’s economy and food supply: glacial melting, increased evaporation, coral reef bleaching, and storm surge flooding (Figure 10.11).

Melting Glaciers and Increased Evaporation Like much of Asia, mainland Southeast Asia’s largest rivers (the Irrawaddy, Salween, Mekong, and Red rivers) are fed during the dry season (November through March) by glaciers high in the Himalayas. These glaciers are now melting at a rate that could result in their eventual disappearance.

As glacial melting accelerates, the immediate risk is catastrophic flooding. While some areas have long been adapted to dramatic seasonal floods, which have taken place in this region for most of human history, many areas are unprepared for floods (see Figure 10.11D).

A longer-term concern is reduced dry-season flows in the rivers where glacial melt water has been the primary source of stream flow. As much as 15 percent of this region’s rice harvest depends on the dry-season flows of the major rivers. The loss of these harvests would strain many farmers’ incomes. In addition, there would likely be food shortages in cities. Coming on top of a global rise in food prices in recent years, this would place further strain on the incomes of poor people throughout the region.

The higher temperatures associated with current trends in global climate change mean evaporation rates will rise, resulting in drier conditions in fields, lower lake levels, and lower fish catches because of changing habitats for aquatic animals. Evaporation that results in reduced river and groundwater levels can also cause saltwater intrusions into estuaries and freshwater aquifers.

Coral Reef Bleaching Global climate change is expected to increase sea temperatures in Southeast Asia, threatening the coral reefs that sustain much of the region’s fishing and tourism industries. A coral reef is an intricate structure that is composed of the calcium-rich skeletons of millions of tiny living creatures called coral polyps (see Figure 10.6B). The polyps are subject to coral bleaching (see Figure 10.11C), or color loss, which results when photosynthetic algae that live in the corals are expelled by a variety of human-instigated or naturally occurring changes. Both rising water temperature related to climate change and oceanic acidification resulting from the absorption of excess CO₂ in the atmosphere can cause bleaching. Ocean acidification is thought to have increased by about 30 percent over the last 340 years, a rate of change that may exceed the ability of ocean creatures to adapt. Bleaching also occurs in response to pollution from urban sources such as sewage discharges, stormwater runoff, or industrial water pollution.

Overfishing can contribute to bleaching as well. Under normal conditions, coral that is assaulted with just one of the bleaching situations recovers within weeks or months. However, severe or repeated bleaching can cause corals to die. Unprecedented global coral bleaching events affecting roughly half of the world’s coral reefs took place in 1998, 2002, 2004, and 2006, and regional events occur somewhere every year. 224. NEW SPECIES OF UNDERSEA LIFE FOUND NEAR INDONESIA

Many of the fish caught in Southeast Asia’s seas depend on healthy coral reefs for their survival. The thousands of rural communities throughout coastal Southeast Asia that rely on fish for food are thus also threatened by coral bleaching. So far, however, the greatest observable impacts on people have been in the tourism industry. In the Philippines, the coral bleaching of 1998 brought a dramatic decline in tourists who come to dive the country’s usually spectacular reefs, resulting in a loss of about U.S.$30 million to the economy.

Storm Surges and Flooding Although the relationship is not yet entirely understood, violent tropical storms seem to be increasing in both number and intensity as the climate warms. When Typhoon Haiyan hit in 2013, it became the strongest typhoon to make its way onto land in recorded history. Haiyan struck the Philippines, killing at least 5600 people and leaving millions homeless. Climatologists studying data on tropical storms predict that the entire Southeast Asian region will have a somewhat higher number of typhoons over the next few years and that the duration of peak winds along coastal zones will increase. This is significant because many poor, urban migrants have crowded into precarious dwellings in low-lying coastal cities such as Manila, Bangkok, Rangoon, and Jakarta, where coping with high winds, flooding, and the aftermath of storms will likely be a frequent experience (see Figure 10.11A).

One goal of all governments in this region is to reduce the amount of fossil fuel consumption, and some are meeting this goal despite the frequently high start-up costs of doing so. Both the Philippines and Indonesia have significant potential for generating electricity from geothermal energy (heat stored in Earth’s crust). This energy is particularly accessible near active volcanoes, which both countries have in abundance. The Philippines already generates 17 percent of its electricity from geothermal energy; it is second only to the United States in the amount of geothermal power it generates. By some estimates, geothermal energy could eventually provide a majority of Indonesia’s energy needs. Solar energy is another attractive source, given that the entire region lies near the equator, the part of the planet that receives the most solar energy. For most countries, however, wind is the most cost-effective option, especially in Laos and Vietnam, where many population centers are in high-wind areas.