Fuel, food, and world politics Biomass grows faster in the humid tropics than anywhere else, and countries in these regions are now among the most impoverished in the world. It is clear that the world will run out of liquid fuel resources during the next century. Our dependence on liquid fuels is almost irreversible, and this should give the Third World countries in the tropics a product they can sell one that could help them break out of the cycle of poverty. (23,110) Such a shift could cause problems as well as benefits. Although these countries would benefit from cheaper fuel and would gain income, they usually have difficult debt, resource, and population problems and might be forced into a situation in which fuel production is increased at the cost of food production, causing even greater poverty and malnutrition (110,111) if their populations continue to rise at current rates of growth. Also, even though current food production could provide for everyone on Earth, if politics did not interfere, it is not clear that technology could keep up with explosive population growth (see Chapter 22). This could pose a political problem for the developing countries and for the world as well. Many of these countries have deemphasized the importance of agriculture, thereby depressing farm costs, subsidizing food, and encouraging farmers to migrate to cities, where they generally form a poor lower class. The possibility that the poorer countries might default on their loans in the early 1980s gave rise to the specter of a world financial market could collapse. Loans were forgiven or renegotiated, and the system was held together, but the danger of a future collapse remains as long as the economic disparities do. Some help has been afforded these countries by the green revolution, (see Extension 24.4, The green revolution, fertilizer, and erosion) but much remains to be done. Research on cassava, the fourth most important world source of food energy, could make
Energy, Ch. 23, extension 2 Food, fuel, and world politics 2 a difference. (112,113) Although cassava is not economic as a fuel source in the United States or even in Brazil (an emerging Third World country), (15) it may be possible to use it for both food and fuel in the future. It grows even on depleted soils, takes water stress well, and tolerates high aluminum levels (prevalent in lateritic tropical soils). (112) Some geographical areas have a great number of biomass options for example, the temperate forest. Other areas, such as the polar regions, have little potential for biomass. Nevertheless, in every world region, there is some potential, especially given the small number of plants that are used to feed humans and domestic animals (estimates range from 7 to a more reasonable 85). (107) Fig. E23.2.1 Hawaiian papayas are delicious, but papayas are not commonly available. (Scott Bauer, USDA) Many plants that are not used widely hold out the possibility of nutritional adjuncts to the diets of the entire human race. Humanity depends heavily on just a few crops: wheat, rice, corn, and potatoes, for each of which over 300 million tonnes are harvested each year; barley, sweet potato, and cassava, each harvested at over 100 million tonnes yearly; grapes, soybean, oats, sorghum, and sugar cane, each harvested at over 50 million tonnes annually; millet, bananas, tomatoes, sugar beets, rye, oranges, and cottonseed (for oil),
Energy, Ch. 23, extension 2 Food, fuel, and world politics 3 each produced at over 25 million tonnes each year; and even smaller crops such as apples, yams, peanuts, watermelons, cabbage, onions, beans, peas, mangoes, and so on (see Fig. E23.2.1 for a well-known fruit that is not commonly available in the U.S.). (114) This list comes close to exhausting the standard items available in grocery stores. Fig. E23.2.2 The abiu tree is densely foliaged; it is a light green-leaved evergreen. The fruit is a berry with a caramel flavor. It ripens for up to 5 days after harvest and soon spoils, so the fruit is very fresh when available. Fig. E23.2.3 The cubiu typically has a juicy pulp. It can be grown in acid soil of low fertility. (INPA, Brasil) Plants such as grain amaranth, oca (a yam-like tuber), yam beans (jicama), arracacha (a celery-like root), nunas (popping beans), and quinoa were grown by the Aztecs and the
Energy, Ch. 23, extension 2 Food, fuel, and world politics 4 Incas for food; in modern times, their use has languished. (114) The pejibaye palm (Bactris gasipaes) of Central America produces a nutty fruit that is ideal for healthful eating. (114,115) Edible berries including the abiu (Pouteria caimito), the araza (Eugenia stipitata), and the cubiu (Solanum sessiliflorum) grow well. (115) The groundnut (Apios americana) was once an important American Indian food, and the bambara groundnut (Voandzeia subterrania) is even now widely grown in Africa. Both taste good and could serve as dietary supplements elsewhere (they are similar to peanuts. (114) In semidesert areas, the tepary bean (Phaseolus acutifolius), the marama bean (Tylosema esculentum Caesalpiniaceae), and Ye-eb nut (Leguminosae Caesalpinioideae Cordeauxia edulis) could help feed people where no other food plants grow easily. (114) Dessert fruits abound in the tropics. Many South American fruits have been neglected in the north naranjilla (Solanum quitoense), cocona (Solanum sessiliflorum Dunal), pepino dolce, tree tomato, cape gooseberry (of the potato family); cherimoya (Annona cherimola), soursop (Annona muricata), sweetsop (Annona squamosa), and atemoya (of the Annonacia family); black sapote; carambola (Averrhoa carambola, native to southeast Asia, Fig. E23.2.4); and plantain. (114) Some of these fruits are becoming more readily available as immigration from Central and South America increases.
Energy, Ch. 23, extension 2 Food, fuel, and world politics 5 Fig. E23.2.4 Carambola came originally from Malaysia or Indonesia. The Arkin variety is shown. Carambola fruit are also known as star-fruit. (Scott Bauer, USDA) The star apple (Pouteria caimito, Fig. E23.2.5) is a large fruit also known as the caimito. The fruits can be as large as 10 cm in diameter, similar to the size of an apple. The tree, an evergreen, is native to South America, and can grow to a height of 20 m. The leaves are dark green on top and yellow brown on the bottom, so this is sometimes planted as an ornamental tree. Similarly, immigrants from Asia are bringing their fruits with them to America. Many of them resemble the lychee nut (Litchi chinensis) possibly familiar to diners frequenting Asian restaurants. The longan (Euphoria longan, Fig. E23.2.6) comes from south Asia. Another lychee relative is the rambutan (Nepthelium Lappaceum, Fig. E23.2.7). The spikes are soft, not spiny.
Energy, Ch. 23, extension 2 Food, fuel, and world politics 6 Fig. E23.2.5 The star apple (Chrysophyllum cainito) is quite sweet. Fig. E23.2.6 The longan (dragon s eye), probably comes originally from Myanmar. It is closely related to the lychee nut, and has a somewhat smoky flavor. New varieties can grow to a diameter 2.5 cm. (Scott Bauer, USDA)
Energy, Ch. 23, extension 2 Food, fuel, and world politics 7 Fig. E23.2.7 Rambutan is a relative of the lychee nut and the longan. Trees produce yellow, pink, or red fruit about 5 cm long, that have juicy and delicious pulp around a single seed. Durian (Durio zibethinus, Fig. E23.2.8) has a very pronounced odor that many find repulsive (it has been compared to rotten onions) but others appreciate (some characterize the durian as the king of tropical fruits). Durian came originally from Malaysia or Indonesia. The fruit has a mass of several kilograms and when the ripe fruit fall from the trees, people have been injured. The fresh fruit is less redolent than older fruit, and the texture is custard-like. Durian is often fermented as a preservation measure, and forms the staple of many south Asian dishes. Fig. E23.2.8 The durian has a custard-like consistency within a spiny rind.
Energy, Ch. 23, extension 2 Food, fuel, and world politics 8 Ripe mangosteens (Garcinia mangostana, Fig. E23.2.9) are dark red (they are often known as purple mangosteens). The rind is thick and resists insect attack. The fruit has several juicy segments, with a pulp that melts in the mouth. Some have called this fruit the queen of fruits, and unlike the durian, almost everyone enjoys the fruit at first eating. (Mangosteens have no connection to mangos.) Fig. E23.2.9 Purple mangosteens grow only in hot wet climates. Yellow mangosteens are much more acidic, but may be preserved or used as pie filling. Sales of tropical fruits can help the economies of poor countries while providing indigenous people with a reason to protect the forests instead of exploiting them by cutting them down. This could help transfer funds to the local people, who can spend them in useful ways undeterred by orders from the capital to give themselves a better life.