Impacts of Climate Change on the Water Sector in Mexico

Abstract

Climate and the water cycle are intimately related; so, any change in temperatures and precipitation patterns estimated for different climate change scenarios will have an impact on the availability of water resources. The objective of this study is to present a set of regional temperature and rainfall projections for Mexico under the IPCC's AR6 climate change scenarios and estimating the possible impacts of climate change on Mexico's water resources. A set of regional temperature and rainfall projections for Mexico under the IPCC's AR6 climate change scenarios during the present century were generated by the Climate Change Knowledge Portal (CCKP) of the World Bank and together with the projections of soil moisture, Normalized Difference Vegetation Index (NVDI), Standardized Precipitation Evapotranspiration Indices (SPEI) and droughts will be evaluated. The vulnerability of Mexico's water resources. The regional models for Mexico under the IPCC AR6 climate change scenarios show temperature increases ranging from 0.5 to 5 °C, while the % change in rainfall will range from -20.3% to 13.5% depending on the scenario and analysis period. Low soil moisture (mm), negative changes in NDVI and SPEI 12 show that the North, West and Bajío areas presented reductions in precipitation and increase in temperature that caused a severe deficit of soil moisture and water stress in plants considering these areas with scarce vegetation and presence of semi-permanent meteorological drought. Under these scenarios it is expected that practically the entire country will be subjected to moderate droughts (Central and South) to extremely strong (North) that will last and sharpen between now and the end of the century. These conditions have already been registered in the main hydrological basins of Mexico and if adaptation and mitigation measures are not adopted, the availability of water is put at risk and with it the food security of the country. Also, in addition to the decrease in rainfall, it is estimated that they are more intense with the presence of extreme events, which will increase the vulnerability of some basins throughout the country, in the Central and Northern areas with extreme drought events, while in the Southeast with floods. Both scenarios would put at risk the availability of water both in quality and quantity throughout the country. To reduce the effects of climate change on water resources in Mexico, it is necessary to design and prioritize adaptation actions and implement mitigation measures that avoid intensifying the effects of climate change in the most vulnerable hydrological regions of the country.