Assessing current and potential rainfed maize suitability under climate change scenarios in México

Abstract

We conducted an assessment on the capacity to grow maize under rainfed conditions as well as under simulations of climate change scenarios in México. The selected method took into account the most limiting factor from different variables that maize requires to grow. These factors were compared, resulting in potential areas for maize distribution, classified in four different suitability levels: suitable, moderately suitable, limited suitability and not suitable. The emissions scenarios of climate change selected were A2 and B2 by 2050, including the GFDL-CM2.0, UKHADGEM1 and ECHAM5/MPI models. The results indicated that in base scenario, 63.1% of the national surface presents some degree of maize growing suitability. Specifically, 6.2% of the national surface indicated suitable conditions, while 25.1 and 31.6% had moderated and limited conditions, respectively. According to the climate change models, we were able to determine the full suitability level is also the most vulnerable one and as a consequence, this will also be the most aggravated one by decreasing its surface 3% according with UKHadley B2 and up to 4.3% in accordance with ECHAM5/MPI A2. This will make the limited suitability classification the one with the largest national territory, as much as 33.4%, according to ECHAM5/MPI A2 and up to 43.8% reflected by the GFDL-CM2.0 A2 model. The ECHAM5/MPI model indicates the most adverse conditions for maize growth, while GFDL model represents the less aggravating. All this clearly reflects that the natural conditions given for maize growing will become more restrictive, making it critical to implement environmental adapting measures.