Climate Scenarios

There is now a broad scientific consensus that climate change caused by the intensification of the anthropogenic greenhouse effect has already had impacts on the natural environment and that those impacts will be worse over the century. One of the most vulnerable sectors to climate change in countries of southern Europe is the water resources sector. Over the past 40 years we have already observed in Portugal a slight decrease of the mean annual precipitation and a clear trend of increased variability of rainfall in winter, with higher frequency of very dry and very rainy winters. Projections for the end of the century, obtained with various global climate models available, are in agreement with regard to an intensification of these trends.

This project will use regionalized climate scenarios which will generate the mean and variability of climate variables such as temperature and precipitation.These scenarios are based on global climate models (eg HadCM3) and validated with observed climate series in the areas under study. The projections produced allow to assess the frequency of future extreme weather events, such as high rainfall in short periods of time and prolonged severe droughts. The global climate scenarios also allow making projections of rising sea level, a phenomenon that will havean increasing influence on the Tagus estuary and its saline.