Assessing vulnerability to climate change in Medellín, Colombia

In Latin America, cities often face structural challenges such as the inequality gap, poverty, and informal urbanization processes where the individuals with fewer resources inhabit marginal lands more exposed to climate hazards and are more vulnerable or predisposed to be negatively affected by climate-related events. Without proper and targeted interventions, the increase in the vulnerability of these communities to climate change is imminent, bringing along a cost in terms of development. In Medellín, the city expects an increase in frequency and intensity of precipitation, favoring floods and landslides and threatening low-income areas in comunas 1-Popular, 3-Manrique, and 8-Villa Hermosa. Understanding that resources are limited, and interventions must be of high impact, this research aims to determine the most influential factors affecting exposure, sensitivity, and adaptive capacity to climate change in the previously mentioned Comunas under the context of unplanned settlements, poverty, and informality. Analyzing 2014, when vulnerability reduction policies are approved, and 2021 for comparative purposes. The index-based vulnerability assessment is conducted through Principal component analysis (PCA) using the software Stata, a statistical method for variables reduction to their essential features, finding the variables that can summarize the most relevant patterns in the data, and assigning weights to the indicators accordingly. The method is applied separately to each vulnerability component. The results reveal that most neighborhoods experienced vulnerability increasing between 2014 and 2021 due to higher sensitivity and decreased adaptive capacity. The vulnerability is primarily influenced by houses located in high landslide hazard areas, houses made with temporary materials, overcrowding, low income, high population below 14 years old, lack of access to public services, low formal land tenure, and low education level. The results highlight that addressing persistent structural conditions such as poverty and social inequality is crucial for reducing vulnerability. However, each neighborhood displays different challenges that range from low access to Wi-Fi to intra-urban displacements. In general terms, the decreasing adaptive capacity sets off the alerts because it entails the impact intensification, creating, in turn, the increase in sensitivity, also observed in the study area. The index can be extended to the city and used as monitoring and assessing system, for urban planning purposes, for proposing strategies, for supporting community initiatives, and for targeting interventions and prioritizing resources in policies on education, poverty, and housing, to enhance adaptive capacity and minimize sensitivity.