In September 1991, the space shuttle flew across the arid central Andes Mountains, taking this clear picture of Lake Poopo in western Bolivia (left, foreground). To the east beyond the Andes, “like another sea,” as the astronauts described it, the lowlands of tropical South America are cloaked in a vast, formless pall of smoke (center). The smoke is mainly generated by human activities — including the burning of forests to clear the land for agriculture and cattle ranching. This type of burning is an annual event in Amazonia and other parts of the world during the dry season (June through September in the southern hemisphere).
Nineteen percent of the forests and woodlands in South America have been lost since 1850, with most of the recent losses occurring in and along the margins of the Amazon rainforest. Ecological concerns related to the burning of Amazon forest include an increase in greenhouse gases in the atmosphere, the loss of species and reduction in biodiversity in one of the most biologically diverse parts of the world, disruption of the hydrological cycle, and threats to the cultures of local Amerind populations.
September 1991, image STS-48-151-140.