Climate Change Scenarios for the Northeast Region of Brazil through the Statistical Downscaling Technique

Abstract

The impact of climate change on precipitation and maximum and minimum temperatures patterns in the Northeast region of Brazil is investigated based on the mean results of four global climate models, ECHAM5-OM from Germany, HADGEM2-ES from the UK, BCM2 from Norway and the CNRM-CM3 of France, for two scenarios of greenhouse gas emissions, A1B and A2, that had their future projections regionalized for the period 2021-2080 using the statistical downscaling model. The ability of the models to simulate present climate conditions was checked for the 1961-1990 control period, presenting very satisfactory results, and validated for the period 1991-2000. The analogues method was employed to perform statistical downscaling and to find predictor-prediting relationships. The results point to a significant reduction in rainfall in the respective rainy periods of the northeastern subregions, and the highest temperatures increase in the first semester, with a tendency to decrease in large areas of the northern Northeast sector in the second semester, mainly for scenario A2. For the minimum temperatures the results show a tendency of increase in all the year with highlight for the winter months.

Keywords:
statistical downscaling; climatic changes; rainfall; temperature; Northeast Brazil