For subsistence farmers in Africa or Andean peasants in Latin America, where use of oil-based inputs is negligible or nonexistent, the loss of topsoil is a more serious threat to food production than oil price rises are. Economic trends and ecological systems interact continuously in ways that we sometimes fail to understand and with consequences that we frequently do not anticipate. Policies that are economically successful in the short run can be ecologically and economically disastrous in the long run. The very practices that lead to excessive erosion often yield short-term production gains or even surpluses, creating an illusion of progress. The interactions between the global economy and the earth's natural systems, cycles, and resources are legion.
Acid rain affects forest productivity, which in turn raises costs in the forest products industry.
Population growth hastens deforestation, which may reduce rainfall. Fossil fuel combustion raises atmospheric levels of carbon dioxide, which in turn alters climate and eventually world agriculture. The growing demand for protein triggers over-fishing, which in turn leads to the collapse of fisheries. These are but a few of the important links between the economy and the ecosystem. Of these linkages, one that seems destined to attract attention soon is that between soil erosion and Third World debt.