Alejandro Ismael Monterroso

Two methods to assess vulnerability to climate change in the Mexican agricultural sector

We applied two methods to assess vulnerability to climate change in Mexico’s agricultural sector. The first one was a principal component analysis (PCA) that weighted each variable separately. For the second one, we integrated the variables in a linear array in which all variables were weighted equally, and then, we used the arithmetic sum of the sub-indices of exposure and sensitivity minus the adaptive capacity to obtain the vulnerability index. We discuss the similarities and differences between two methods with respect to municipal-level maps as the outputs. The application of the method for the agricultural sector in Mexico gave us the spatial distribution of the high- and very-high vulnerability categories, which we propose as a tool for policy. The methods agreed that the very-high vulnerability category is present in 39 municipalities. Also we found that 16xa0% of the total population in the country is located in high-exposure areas. In addition, 41xa0% lives in municipalities identified as highly-sensitive. In terms of adaptive capacity, 20xa0% of the population lives in 1273 municipalities with low-adaptive capacity. Finally, we discuss the need for information regarding vulnerability at the national level to guide policies aimed at reducing exposure and sensitivity and increasing adaptive capacity.

Exposure to climate and climate change in Mexico

An index with the potential to integrate different climate hazards into a single parameter is required to guide preventive decision making. We integrated in a single index the degree of exposure to climate that the nations municipalities have. We selected this spatial scale because the municipality is the basic unit of administrative and economic planning; consequently, this is the scale at which policies of adaptation to climate change must be fostered. We conceptualized exposure as the sum of historic extreme events, the degree of ecosystem conservation and current climate and its future scenarios. This approach allowed us to create a climate hazard exposure index at the municipality scale integrating past and present. Maps of this index can be constructed to serve as a medium of risk communication and to aid policy design. We used information from eighteen variables to statistically standardize and compute the hazard exposure index by applying empirical formulae. We found that actually, out of ten Mexicans, three live in flood-prone zones, three may suffer the passage of tropical cyclones, five reside in drought zones and two live in extreme drought regions. Additionally, hailstorms affect five out of ten Mexicans, while eight out of ten are affected by frosts. Incorporating climate change, in the future more municipalities and a higher population will live in high exposure. Because understanding exposure is a necessary prerequisite to understanding vulnerability, knowledge of the spatial distribution of exposure should be useful for reducing the identified climate hazard exposure and vulnerability to climate change.

Adaptive capacity: identifying the challenges faced by municipalities addressing climate change in Mexico

In many countries, administrative and economic planning occurs at the municipality level. We believe that relevant policies for adapting to climate change can be initiated at this level. Thus, this article assesses the adaptive capacity of Mexican municipalities and populations to address climate change to measure the challenge that climate change represents. The method was developed as follows. We selected 19 indicators organized into four categories: human, social, financial, and natural. The information was standardized, and we used empirical formulas to obtain an adaptive capacity index. The index was mapped, and the distribution showed the spatial capacity for the adaptation of Mexican municipalities. We discuss the contributions these indicators made to the adaptive capacity and show that the human capital variables were the most relevant for defining the adaptive capacity of municipalities. We also applied this index to the observed climate exposure and sensitivity of Mexican municipalities to climate change. Thus, we propose a matrix to measure the dimensions of the challenges posed by climate change in terms of both decision-making and policy management for increasing the adaptive capacity of municipalities and populations within a nation.