Achieving a truly sustainable energy transition requires progress across multiple dimensions beyond climate change mitigation goals. This article reviews and synthesizes results from disparate strands of literature on the coeffects of mitigation to inform climate policy choices at different governance levels. The literature documents many potential cobenefits of mitigation for nonclimate objectives, such as human health and energy security, but little is known about their overall welfare implications. Integrated model studies highlight that climate policies as part of well-designed policy packages reduce the overall cost of achieving multiple sustainability objectives. The incommensurability and uncertainties around the quantification of coeffects become, however, increasingly pervasive the more the perspective shifts from sectoral and local to economy wide and global, the more objectives are analyzed, and the more the results are expressed in economic rather than nonmonetary terms. Different strings of evidence highlight the role and importance of energy demand reductions for realizing synergies across multiple sustainability objectives.

Abstract:The transport sector is the second largest and one of the fastest growing energy end-use sectors, representing 24% of global energy-related greenhouse gas emissions. The International Energy Agency has developed scenarios for the transport sector within the overall concept of mitigation pathways that would be required to limit global warming to 2 °C . This paper builds on these scenarios and illustrates various passenger travel-related strategies for achieving a 2° transport scenario, in particular looking at how much technology improvement is needed in the light of different changes in travel and modal shares in OECD and non-OECD countries. It finds that an integrated approach using all feasible policy options is likely to deliver the required emission reductions at least cost, and that stronger travel-related measures result in significantly lower technological requirements.

As of June 2017, 150 countries have ratified the Paris Climate Agreement. This agreement calls for, among other things, strong reductions in CO 2 emissions by 2030 and beyond. This paper reviews the Nationally Determined Contribution (NDCs) plans of six Association of Southeast Asian Nations (ASEAN) countries and compares their current and projected future CO 2 levels across sectors, and their stated targets in the context of their economic and demographic situations. This comparison reveals wide variations in the types of targets, with the "ambition" level changing as the perspective changes from total CO 2 to CO 2 /capita and per unit gross domestic product (GDP). We also review national plans as stated in NDCs and find that while there are many types of policies listed, few are quantified and no attempts are made to score individual or groups of policies for their likelihood in achieving stated targets. We conclude that more analysis is needed to better understand the possible impacts of current policies and plans on CO 2 emissions, and whether current plans are adequate to hit targets. Considerations on better aligning targets are also provided.

Global transportation energy use is steeply rising, mainly as a result of increasing population and economic activity. Petroleum fuels remain the dominant energy source, reflecting advantages such as high energy density, low cost, and market availability. The movement of people and freight makes a major contribution to economic development and social well-being, but it also negatively impacts climate change, air quality, health, social cohesion, and safety. Following a review published 20 years ago in the Annual Review of Environment and Resources (then named the Annual Review of Energy and the Environment) by Lee Schipper, we examine current trends and potential futures, revising several major global transport/energy reports. There are significant opportunities to slow travel growth and improve efficiency. Alternatives to petroleum exist but have different characteristics in terms of availability, cost, distribution, infrastructure, storage, and public acceptability. The transition to low-carbon equitable and sustainable transport will take time but can be fostered by numerous short- and medium-term strategies that would benefit energy security, health, productivity, and sustainability.

The lack of suitable tools to assess sustainable mobility measures' costs, benefits and overall impacts is a significant factor impeding their implementation. Cost-benefit analysis (CBA) is often applied to large-scale infrastructure projects, but does not capture all relevant socio-economic impacts. Small-scale but potentially highly cost-effective measures often do not have the critical mass to warrant a thorough cost-benefit analysis. This paper reviews existing assessment methodologies, including their advantages, limitations and application to different urban mobility measures, and current assessment practice in cities based on survey results. Based on these analyses, a holistic approach for project appraisal is proposed, consisting of aspects of a multi-criteria analysis (MCA) and CBA and applicable to a variety of urban mobility measures.

This paper outlines the key elements of a low‐carbon stabilization pathway for land transport, focusing on the potential of key policy measures at the local and national level, opportunities for synergies of sustainable development and climate change objectives, and governance and institutional issues affecting the implementation of measures. It combines several approaches to provide an integrated view on the decarbonization of the transport sector based on recent literature. It will assess the quantitative basis potential climate change mitigation pathways and will then look into policy and institutional aspects that relate to the feasibility of these pathways. This combination of quantitative and qualitative analysis to measure the potential, options, and feasibility of climate change mitigation strategies in the transport sector aims to synthesize recent papers on the subject and draw conclusions for future research. WIREs Energy Environ 2017, 6:e257. doi: 10.1002/wene.257 This article is categorized under: Energy Policy and Planning > Economics and Policy Energy and Development > Climate and Environment

Considerable efficiency gains can be made costeffectively to set the transport sector on a sustainable development pathway. They can be achieved through already available technologies and practices, which will not only reduce greenhouse gas emissions significantly, but also generate social, environmental and economic co-benefits. However, progress in the take-up of low-carbon mobility measures substantially lags behind the potential. A number of barriers contribute to this lack of uptake. This paper explores those barriers by focusing on vehicle fuel efficiency in particular, but will also touch on the wider policy framework to improve the efficiency of the transport sector and reduce emissions. The paper suggests that a combination of fuel pricing, differentiated vehicle taxation, vehicle standards and the provision of modal choice are necessary to minimise rebound effects and significantly curb transport sector greenhouse gas emissions at low-or even negative cost.

Electric mobility is beginning to enter East African cities. This paper aims to investigate what policy-level solutions and stakeholder constellations are established in the context of electric mobility (e-mobility) in Dar es Salaam, Kigali, Kisumu and Nairobi and in which ways they attempt to tackle the implementation of electric mobility solutions. The study employs two key methods including content analysis of policy and programmatic documents and interviews based on a purposive sampling approach with stakeholders involved in mobility transitions. The study findings point out that in spite of the growing number of policies (specifically in Rwanda and Kenya) and on-the-ground developments, a set of financial and technical barriers persists. These include high upfront investment costs in vehicles and infrastructure, as well as perceived lack of competitiveness with fossil fuel vehicles that constrain the uptake of e-mobility initiatives. The study further indicates that transport operators and their representative associations are less recognized as major players in the transition, far behind new e-mobility players (start-ups) and public authorities. This study concludes by identifying current gaps that need to be tackled by policymakers and stakeholders in order to implement inclusive electric mobility in East African cities, considering modalities that include transport providers and address their financial constraints.