La capacité de charge carbone (C3) comme outil de monitoring-controlling du modèle urbain d’Alger vers la soutenabilité environnementale et la résilience climatique

Abstract

Beyond the critical triad that tyrannizes human civilisations such as 'energy stress, raw material availability and regression of ecological assets', climate change phenomenon, discovered at the beginning of the 20th century, is considered to be the most greatest factor causing major imbalances in our modern world, threatening, more than ever, the fundamental cycles that govern the biosphere and, consequently, shrinking its hospital capacity. Following the logic of causes and effects, we perceive that global warming phenomenon, hypothetically speaking, is a local anthropic phenomenon generated through the combustion of fossil fuels (coal, gas and oil), massive deforestation and intensive agriculture. All these anthropogenic activities are considered to be a source of greenhouse gas emissions (GHG). Regarding the threats to human population and biodiversity, urban ecosystems must be crystallized around two capstones orchestrated by (i) mitigation and (ii) adaptation measures. Algeria, as a developing country on the southern shore of the Mediterranean, is trying to mitigate its anthropogenic emissions in parallel with its objectives submitted to the UNFCCC in 2015. Namely, at the national level, Algeria has recently increased the dose of its political voluntarism (including the establishment of a set of aggregated initiatives, operational tools and an arsenal framework) in order to tackle climate change and reduce, consequently, its direct carbon emissions (so called territorial emissions). However, its technocratic, unbalanced and isolated vision has rendered the initiatives sterile and ineffective, therefore, the assigned target will not be reached. Our research aims to reweave the networks between the urban stakeholders and the architecture of the local urban planning tools (PDAU) around the complexity of climate change at the local scale, by focusing on the functioning of Algiers’ socio-economic metabolism and double-focusing on the functioning of the city through a vision according to which the city would be considered as a white box contrary to the idea of the black box which depicts only the behaviors of cities. Therefore, we aim to build a decision support tool that would be supposed to respond to the state of emergency of action, the sterility of the strategies undertaken and the slowness of urban operational practices in Algiers. Not surprisingly, Algiers’ urban ecosystem must recognize, first of all, the thresholds that govern it and, subsequently, operates by taking into consideration its thresholds in order to maintain the functioning of biological cycles (and some bio-essential cycles) and not to alter the life of living organisms (biodiversity). It is from this point of view that the present research draws its strength. The monitoring-controlling tool will be built around two indicators, which are (i) territorial carbon emissions and (ii) carbon sink capacity, the results will be presented in t CO2. The model will be applied to the most populated Wilaya in the country (Algiers) since it is experiencing an important urban growth (spatial, demographic and economic). Carbon Carrying Capacity (C3) would then symbolize a driving force to rebuild Algiers towards a more sustainable, inclusive, resilient and low-carbon city.