Assessing the role of urban ecological infrastructure in adapting to climate change impacts: a case of the city of Johannesburg Metropolitan Municipality, South Africa

This study evaluated how Urban Ecological Infrastructure (UEI) could be used for climate change adaptation in the City of Johannesburg (CoJ) Metropolitan Municipality. The objectives included analysing climate variability trends from 1993 to 2023, assessing the planning and implementation of UEIs from a municipal perspective, and using the i-Tree Canopy Model to quantify and value the importance of ecosystem services provided by green UEIs. The Climate Justice and Complex Systems theories influenced the study. The integration of these two theories allowed for an intricate assessment of the climate effects within the study area. The study employed a pragmatic paradigm and a convergent parallel mixed-method design. The ClimPACT v3.1.6 software was used to analyse daily temperature and rainfall data from 1993-2023 obtained from the South African Weather Service. Additionally, 16 stakeholder interviews and a review of 14 institutional documents were conducted to highlight the planning and integration of UEIs as a climate adaptation tool. The i-Tree Canopy Model was utilised to assign economic values to UEI-provided ecosystem services. The study’s results indicated increasing climate variability, with minimum and maximum temperatures rising by 0.03°C and 0.025°C, and annual precipitation increasing by 5.407mm. The interviews and document review revealed a significant gap between institutional plans and implementation, with climate change not being fully prioritised and understood. The i-Tree Canopy Model results highlighted the importance of the city's regulatory ecosystem services provided by GUEIs. With carbon sequestration alone, the city saves R22,163,600,100. Overall, the study indicated that UEIs are a useful tool towards climate adaptation; the institutional fragmentations and silos in the governance structures, however, pose great threats towards the city reaching urban sustainability and climate resilience.