This article presents a review of the state of the art in studies of climatic trends for Brazil , developed in the last 50 years and based on observations.

Next, an analysis is done of future climate scenarios (until the year 2100), generated by the models employed in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC-AR4) for Brazil as a whole, and for specific regions such as the Northeast, the Amazon, and Bacia do Prata.

IPCC-AR4 projections until 2100 are discussed in relation to scenarios analyzed in previous studies employing the patterns of the Third Assessment Report of IPCC, published in 2001.

The analysis and discussions presented pertain to rain and river flows.