Transport Emissions & Social Cost Assessment: Methodology Guide
A Guide to the Methodology of Estimating Transport Emissions Inventories and the Associated Social Costby -
The Transport Emissions & Social Cost Assessment is a project under the World Resources Institute’s Sustainable and Livable Cities Program, funded by the Caterpillar Foundation. The project aims to develop a methodology guide, with a simple MS Excel– based tool, to estimate transport emissions inventories and evaluate the associated social impact costs. The scope of the guide and tool covers six air pollutants (NOX, SOX, PM2.5, PM10, CO, and HC) and three GHGs (CO2, CH4, and N2O) for 18 types of transport modes at either the national or city level, specifically for the regions with limited data accessibility and weak data quality. With the methodology of social cost evaluation, the guide and tool can help with more cost-efficient policy-making. The MS Excel– based tool (Transport Emissions & Social Cost Assessment: TESCA version 1.0) is provided in a separate file.
About This Study
Before introducing any mitigation policies, it is essential to thoroughly quantify the emissions inventories and impact costs. However, many developing countries do not have the capacity to quantify the emissions inventories and impact costs from the transport sector because of limited technical support, methodology, data, and awareness. This study was thus designed to help these cities and countries fill such gaps.
The Transport Emissions & Social Cost Assessment is a project under the World Resources Institute’s Sustainable and Livable Cities Program, funded by the Caterpillar Foundation. The project aims to develop a methodology guide and a simple MS Excel– based tool to estimate transport emissions inventories and evaluate the associated social impact costs. The methodology guide and the tool are developed specifically for developing countries and cities, where the statistical system for the transport sector is still weak in terms of data availability and quality. The guide and tool are designed to estimate the inventories of six air pollutants (NOX, SOX, PM2.5, PM10, CO, and HC) and three GHGs (CO2, CH4, and N2O) for 18 types of transport modes at either the national or city level. On this basis, the range of social cost for each type of emissions can be roughly evaluated and policymakers and decision-makers can create more cost-efficient policies and actions based on the results. The first version of the tool (Transport Emissions & Social Cost Assessment: Tool version 1.0) was designed in 2014 and was successfully tested in Chengdu, the rapidly developing capital of Sichuan province in southwest China (a separate case study report—Transport Emissions & Social Cost Assessment: Case of Chengdu—is available upon request). To make this document more concise, I provide the MS Excel– based tool (version 1.0) in a separate file.
This report, Transport Emissions & Social Cost Assessment: The Methodology Guide (the guide), is a methodology document associated with the tool (v1.0) under the above-mentioned project. The guide introduces a simple, macro-level methodology framework for transport emissions inventory and social cost evaluation. It also discusses the detailed input data required for evaluation, as well as the data quality analysis approach. Finally, the guide includes discussion of how to interpret the evaluation outputs and their uncertainties. It summarizes four kinds of outputs, as the indicative results, from the tool: (1) emissions inventories, (2) emissions social cost, (3) eco-efficiency indicators (e.g., tonnes of PM2.5 per vehicle kilometer traveled [VKT]), and (4) data quality analysis.
Uncertainties And Future Work
Although the guide provides a methodological framework for transport emissions inventory and social cost assessment, it is important to notice that the emissions data and social cost (especially the health costs) data are not equally available and equally reliable. This means that the evaluation of emissions social cost will have more uncertainties than the inventory estimates. This reality cannot be avoided in the long term. Estimating social costs associated with various air pollutants is difficult, and the uncertainties are usually ignored in policymaking. Therefore, it is also the responsibility of this guide to raise awareness of such uncertainties and persuade policymakers and researchers to allocate greater resources and time to the relevant research in order to obtain more reliable estimates and develop accurate policies.
In the future, the study team will (1) further reduce the uncertainties in the emissions social cost evaluation; (2) apply the updated guide/tool to more cities in the world, helping them understand their local transport emissions inventory, social impact, data quality, and the eco-efficiency of the transport system; (3) work with WRI’s GHGP/GPC tool family to contribute to global cities’ emissions benchmarking; and (4) support the social cost-benefit analysis for local clean transport policies and technologies.
The methodology guide has six chapters. Chapter 1 introduces the background, objectives, and gives a quick tour of the guide’s main components. Chapter 2 explains the methodology framework for transport emissions inventory and social cost evaluation, which includes the application scope and methodologies for top-down and bottom-up approaches. Chapter 3 introduces the methodology of data quality analysis and the case of China in the context of poor data quality in developing economies. Chapter 4 discusses the key inputs and defaults required for emissions inventory and social cost evaluation. Chapter 5 discusses how to present and interpret the indicative results, which include the indicators of emissions inventory, emissions social cost, eco-efficiency results, and database quality. Chapter 6 suggests future studies and applications.