This condensed version was prepared to be read together with the original Portuguese-language version, Atlas ambiental de Porto Alegre. The Environmental atlas of Porto Alegre presents the natural history of the city as advocated by the great naturalists of the last century, but using the tecnnologies, theories and cosmovision of the end of the 20th century. Besides a large amount of superbly documented data, the Atlas unites the state-of-art and the knowledge of the frontiers of the sciences that describe and explain the dynamics of the natural and constructed systems in the municipality. Black and white. The Portuguese version presents 124 watercolors, 611 photos and 98 maps and satellite images, besides graphs.