The study set out to understand and demonstrate the role the ICT sector could play as a critical enabler in the transition and progress towards an energy– efficient, low carbon economy. More specifically, the study of sustaining ICT for sustainability has twofold intent: (2) to investigate the direct footprint of ICT sector and explore how it can be tackled through adopting sustainable design–based solutions; and (2) to highlight the enabling potential of ICT sector to mitigate climate change and massively improve energy efficiency across the economy, identifying and quantifying the global ICT impacts and opportunities in the context of energy and carbon emissions savings. To achieve the aim of this study, a pertinent and extensive literature review covering theoretical, empirical, and critical scholarship was performed to investigate the phenomenon. The study draws on a variety of sources to survey the unsustainability of ICT sector pertaining to energy–intensive consumption and explore potential solutions through espousing environmental design practice, and also to examine the role of ICT in delivering energy–efficient solutions through its products and services. Validity was ensured through using quality academic and industry literature as well as relevant studies carried out by a range of eminent researchers, experts, and stakeholders (i.e. NGOs, research centers). Findings highlight the unsustainability of ICT sector regarding energy– intensive consumption and concomitant GHG emissions associated with its products and services. Of the whole lifecycle, the use phase of ICT is the most critical. Data centers and telecom networks devour energy. Planned obsolescence entrenched in software design shorten upgrade cycle, which makes software utilities a planet killer as to energy consumption. Alternative sustainable design–based solutions entail using renewable energy and most efficient energy required over ICT’s life cycle – de–carbonization strategy. Also, digitization is an effective strategy for ICT sector to slash energy use per unit. To reduce the footprint of data centers and telecom networks, design solutions vary from hardware and software to technological improvements. Designing out built–in obsolescence in software technology is a key factor in the energy equation. As for the enabling role of ICT, the findings are highly illuminating. The ICT sector must step up its efforts in reducing its direct footprint in order to claim a leadership role in an energy–efficient, low carbon economy. Although the ICT sector’s own emissions will increase because of global growing demand for its products and services, the real gains will come from its enabling potential to yield substantial energy efficiency improvements and emissions reductions across the economy. The sheer scale of the climate change challenge presents smart development mitigation opportunities for ICT sector to deliver environmentally sustainable solutions. The largest identified opportunities are: dematerialization; intelligent transport and logistics; intelligent buildings; smart power supply; and efficient industrial processes and systems. This study provides a novel approach into sustainable design in ICT, underlining unsustainable design practices in ICT sector. Review of the literature makes an advance on extant reviews by highlighting the synergic relationship between ICT design, sustainability, and the economy. / +46 704 35 21 35

Dans le contexte actuel d'urgence environnementale, la consommation de carburant dans le secteur du transport routier, vu son impact négatif sur l'environnement et son rôle socioéconomique, doit évoluer dans une logique de durabilité. Nous initions notre travail de thèse par une approche comparative de 90 pays quant à leur intensité énergétique et leur intensité de CO2 dans le transport routier durant la période 1980-2010. En calculant le coefficient de Theil, nos résultats empiriques mettent en évidence l'existence d'une disparité spatiale et temporelle. En 2010, la Tunisie occupe le 48ème rang et le 38ème rang, respectivement en terme d'efficiences énergétique et environnementale. Elle a une performance énergétique moyenne tout en occupant le 34ème rang selon l'indice général de performance énergétique. Dans une deuxième partie, nous adoptions la démarche de modélisation conceptuelle dont l'objectif est la construction des indicateurs du transport routier énergétique durable. La définition d'un tel indicateur économique est confronté au problème de mesure de la valeur ajoutée réelle de ce secteur du transport. Par l'intermédiaire de l'approche de filtre de Kalman, nous pouvons conclure que la valeur ajoutée de transport informel est d'environ 61% de total de valeur ajoutée de secteur de transport durant la période 1980-2010 en Tunisie. Enfin, nous procédons à une modélisation économétrique des interactions entre les indicateurs de transport routier énergétiquement durable en Tunisie. L'étude de la dynamique des relations causales entre la consommation du carburant dans le transport routier, les émissions de CO2 dus au secteur de transport, la valeur ajoutée réelle de secteur du transport, le prix moyen du carburant, la longueur de l'infrastructure routière et le taux de motorisation se base sur la technique de cointégration de Johansen et le modèle de la Courbe Environnementale de Kuznets (CEK). Les résultats empiriques confirment, d'une part, l'hypothèse de neutralité entre la consommation de carburant et la valeur ajoutée réelle de secteur de transport et, d'autre part, l'hypothèse de CEK stipulant une relation en U-inversée entre les émissions de CO2 et la croissance économique du secteur du transport. Aussi, nous mettons en exergue une relation de causalité unidirectionnelle au sens de Granger allant de prix de carburant vers la consommation du carburant à court terme. Dans ce sens, en utilisant la technique de décomposition de prix, les résultats infirment l'hypothèse d'asymétrie de l'effet de prix sur la consommation de carburant. Avec la prise en compte de facteur technologique, nous estimons l'effet de rebond à l'ordre de 18% à court terme et 51% à long terme. En termes d'implications politiques, ce travail de thèse montre l'importance d'adopter des politiques publiques transversales où la question énergétique du transport routier est résolue en adéquation avec l'offre infrastructurel, la politique de prix de carburant, le droit à la mobilité individuelle et la protection de l'environnement. Une combinaison optimale entre divers instruments fiscal, économique et de régulation parait la meilleure stratégie pour atteindre un tel objectif. Le rôle de la gouvernance énergétique est central pour concevoir et opérationnaliser toute politique de transport routier énergétiquement durable. / As global concern about climate increases, road transport energy consumption, given its impact on the environment and its socio-economic role, must evolve to sustainability logic. First, the present work provides an international comparison of the energy intensity and the CO2 intensity in road transport for a group of 90 countries oer the period 1980-2010. Through the calculated Theil coefficient, our empirical findings highlight the existence of spatial and temporal disparities between coustries. In 2010, Tunisia occupies the 48th and the 38th rank respectively in terms of energy and environmental efficiency.Based on a general index of energy performance in the road transport sector, it is deemed to have a medium energy performance by occupying the 34th rank. Secondly, through the adoption of conceptual modeling approach, several indicators for sustainable energy development in road transport sector are constructed. To measure the real transport value added, we used filter Kalman approach. We denote that the informal transport value added is about 61% during the period 1980-2010.Finally, this thesis studies causal mechanisms between indicators for sustainable energy development related to energy consumption from Tunisian road transport sector. The investigation is made using the Johansen cointegration technique and the environmental Kuznets curve (EKC) approach. It examines the nexus between real transport value added , road transport-related energy consumption, road infrastructure, fuel price, rate of motorization and CO2 emissions from Tunisian transport sector during the same period. Empirical results support the hypothesis of neutrality between energy and income for Tunisian road transport sector, and the hypothesis of an inverted U-shaped EKC for transport CO2 emissions. Also, there is a unidirectional Granger causality running from fuel price to road transport-related energy consumption with no feedback in the short run. In this sense, using price decomposition technique, we refute asymmetric fuel price effect hypothesis. By the introducing of the technological factor, the rebound effect is about 18% in the short run and 51% in the long run. The study shows the importance if enhancing a number of policies for the road transport system through the joint improvement of the fuel price policy, of the road infrastructure policy and of the road vehicles policy. The optimal combination of fiscal, economic and regulatory instruments is the main strategy to achieve these objectives. The energetic governance is necessary in order to maintain sustainable energy road transport.