The impact of climate variability on agricultural employment in Mexico from 1980–2017

fluctuated between 23 and 35 years. This trend suggests a gradual abandonment of agrarian occupations, where younger individuals left first and are recently followed by older individuals (S1 Fig). 3.1.1 Seasonal variability in agrarian occupation. We observed large shifts in agrarian occupation in Mexico within the year. On average over the last13 years (2005–2017), the third quarter (peak rain season) of the year (July-September) had the highest percentage of the employed population in agriculture, with a median of 9.8%, while the first quarter (peak dry season) had the lowest values, with a median of 9% (Fig 4). The second quarter shows a slightly higher value than the first, reflecting an increase in agrarian occupation as the rainy season begins. Conversely, the inverse pattern can be observed in the last quarter, where a decrease in agrarian occupation is correlated with the onset of the dry season. Although the percentage dif- ference between quarters may seem small (0.8%), it corresponds to the seasonal occupation change of approximately 10.5 million people each year. 3.1.2 Interannual variability. We found a strong impact of precipitation variability on agrarian occupation, particularly for those working in rainfed agriculture and livestock raising. For the first case, we found that precipitation strongly influences the decision to remain in the activity in the subsequent year (Fig 5). In other words, the lower the rainfall, the higher the number of workers who quit the rainfed agriculture activity in the next year and vice versa.

The highest rates of abandonment were observed in 1988 and 1983, with 12% and 9% of work- ers leaving the activity, respectively. These years followed the two driest on record. A similar pattern is observed for the livestock sector (Fig 6), but with impacts in the same year. We found a linear and negative relationship between occupation abandonment and precipitation variability (p = 0.06, r = -0.33). Thus, the lower the rainfall, the higher the number of workers who quit the livestock activity in any particular year. Like the previous case, the largest values Fig 3. Population in agrarian occupations from 1980 to 2017. The solid black line represents the total agrarian occupation, including all respondents employed in agriculture and livestock from 1980 to 2017. The dashed line represents farmers, while the dotted line represents livestock farmers. The red line shows the agricultural sector according to ENE data for the period 1998 to 2017, and the brown line covers the period from 2005 to 2017 with ENOE data. The figure illustrates a steep reduction in the number of occupations in Mexican agriculture. (Source of data: Calculations by the authors using EDER 2017 [50], ENOE 2005–2017 [56], and ENE 1998–2004 [54]). https://doi.org/10.1371/journal.pone.0313891.g003 PLOS ONE Agrarian abandonment and extreme events PLOS ONE | https://doi.org/10.1371/journal.pone.0313891 February 10, 2025 9 / 22