Effect of climate change on growth period in Guanajuato

Increasing temperature and modifying rain distribution patterns are two of the most widely documented effects of global climate change. The impacts that these changes are causing in agricultural production processes constitute one of the main threats to food production, especially under rainfed conditions. This study aims to show the changes that have taken place in the availability of moisture for crops and that are attributable to climate change in the State of Guanajuato. The analysis consisted in estimating the Growth Period by the availability of moisture (GP) from the daily historical series of the climate of 58 stations of the National Meteorological Service. The historical series were divided into two periods, the first from 1960 to 1979 and the second from 1980 to 2017. In 1960-1979, the GP start, calculated at 80 % cumulative probability, occurred on day 193 (Julian day), which corresponds to July 11, while in the period 1980-2017, it was presented until day 211, which corresponds to July 30. Regarding the GP duration, calculated at 80 % probability of exceedance, a reduction is observed from 110 days in 19601979 to only 75 days in 1980-2017. If these trends continue, the agricultural area that can be cultivated under rainfed conditions in the State will be drastically reduced in a few years.