Geography of Brazil clearing. Public policies intended to promote sustainable management of timber extraction, as well as sustainable use of nontimber forest products (such as rubber, Brazil nuts, fruits, seeds, oils, and vines), were being discussed intensely in the mid-1990s. However, implementing the principles of sustainable development, without irreversible damage to the environment, proved to be more challenging than establishing international agreements about them. Although 90% of the country is within the tropical zone, the climate of Brazil varies considerably from the mostly tropical North (the equator traverses the mouth of the Amazon) to temperate zones below the Tropic of Capricorn (23°27' S
Tropic of Capricorn was named in the last centuries BC, the Sun was in the constellation Capricornus (Latin for "goat horn") at the December solstice, the time each year that the Sun reaches its zenith at this latitude. Due to the precession of the equinoxes, this is no longer the case; today the Sun is in Sagittarius at the December solstice. The word "tropic" itself comes from the Greek "trope (τροπή)", meaning to turn or change direction, referring to the fact that the Sun appears to "turn back" at the solstices. The Tropic of Capricorn is the dividing line between the Southern Temperate