Assessment of current and future regional climate scenarios for Mexico

Abstract

Current c h a t e and climate change scenarios are the basis for climate change vulnerability and adaptation studies. Comparison between the current situation and the one that would prevail under climate change conditions allows for the identification of vulnerable regions and the quantification of vulnerability. This may be done by evaluating the land area adversely affected by climate change (e.g. with reduction in agricultural yields or decrease in the level of water reservoirs). Specific regionalization criteria and methods based on physical considerations should be applied in the development of regional climate scenarios. This is the principle followed in studies using analogue scenarios. A methodology based on the direct ~nterpolation of general circulation model (GCM) outputs to the study region under 1xC02 and 2xC02 conditions may be used as a first approach for the development of climate change scenarios. That methodology was applied in this study in order to be consistent with the assessments performed by more than 50 countries involved in the U.S. Country Studies Program and to allow for the comparison and integration of the results from several countries. However, an alternative methodology based on multiple regression was also applied by the Scenario task group of the Mexico Country Study. This methodology is considered to be more appropriate for regionalization purposes.