Quantifying and Reducing Greenhouse Gas Emissions from Local Government Cement and Asphalt Purchasing

Abstract

As the effects of anthropogenic climate change come to bear, increasing numbers of local governments are engaging in climate action planning to quantify and reduce their greenhouse gas emissions. Only recently, however, have local governments begun to become aware of the impact of emissions from the materials that they purchase. Some agencies that have completed an inventory of purchasing emissions have found that they constitute more than half of total emissions, with emissions from construction purchasing at the making up the largest portion of these. Despite the large impact that emissions from construction purchasing can have on a local government’s emissions profile, there is a lack of coordinated action mitigate these emissions in most cities and counties. In many cases, these emissions have not even been quantified in a greenhouse gas inventory, or, if they have, have only been quantified in a very rough manner. To assist in the process of reducing these emissions, this thesis scans the available academic and practical literature of planning and engineering and uses these to develop tools and strategies that can be utilized by any local government to quantify and reduce greenhouse gas emissions from purchased cement and asphalt, two of the biggest contributors to construction-related greenhouse gases (GHGs). The deliverables developed here include (1) a materials reporting form that calculates project-level GHG emissions, (2) recommended changes to policies and specifications, and (3) a project-level alternatives analysis methodology. The use of these tools and strategies is then demonstrated through their application to a hypothetical city, “Greenville.” The purpose of this hypothetical case is to show that planning and design techniques for reducing concrete use and low-GHG cement and asphalt engineering technologies, in combination with policies that encourage these practices, have the potential to reduce emissions from these materials by over 50% within an individual project. These reductions, in combination with accurate reporting, can allow a local government to set and meet greenhouse gas reduction targets in this important, yet often overlooked, sector.