The final decade of the 20th century was the most important period yet in establishing a sustainable society for the coming century. After the Earth summit held in Rio de Janeiro in 1992, the world's population was challenged to decrease its environmental impact on the Earth. Nine years after the Rio summit, we are living in a more dangerous and unsustainable world with a higher population, more resource consumption, more waste, and more poverty, but with less biodiversity, less forest area, less available fresh water, less fertile soil, and less stratospheric ozone.