Carbon Footprint and Handprint Assessment for Net Positive Infrastructure Projects in Honduras

Abstract

Sustainable and resilient cities are becoming the norm as societies worldwide are forced to adapt to climate and health threats. Developing nations have a greater responsibility to quickly adopt measures for resilient cities as their usual vulnerability is now exacerbated with the cascading negative effects of the coronavirus pandemic. This global threat, along with the environmental impacts of more frequent extreme weather events, highlight the need for developing nations to implement concrete plans to face the future. Infrastructure improvement and development must be at the forefront of these plans. This thesis analyzed the carbon footprint of the construction phase of an infrastructure project in Honduras and calculated possible handprints to offset this footprint. Infrastructure projects are now encouraged to have sustainable designs with materials and equipment that have a low environmental impact; yet no matter how much of this is accomplished, any activity or product will always have an environmental footprint. Thus, infrastructure projects can offset their unavoidable footprints through handprints. In this study, life cycle assessment (LCA) was used on a case study of a landslide prevention project constructed in Tegucigalpa, Honduras. Most LCA research done in the region has focused on agriculture but not on the construction sector. Therefore, this research expanded the use of LCA and handprinting in Central America. The main research questions determined the major contributors to CO2 emissions from the construction phase as well the handprinting actions needed to offset these emissions. The methodology used consisted of three parts: estimating the project’s bill of quantities, estimating the carbon footprint, and then the handprinting options. For the first part, total quantities were determined using the data from the as-built drawings and other relevant information from the construction documents. For the second part, the global warming potential (GWP) for each item included in the bill of quantities was determined using environmental product declarations, relevant studies or modeling in OpenLCA. And for the third part, handprinting options were estimated using i-Tree software from the USDA Forest Service to calculate how many trees would be needed to offset emissions. Also, calculations were done to estimate the purchase needed of certified emissions reductions (CERs) from the Climate Neutral Now Initiative by the United Nations. Results showed that the major contributor to GWP was concrete, followed by steel and asphalt. This case study had a total GWP of approximately 1,542 mt CO2 eq which could be offset with handprinting options like planting 121 mango trees or purchasing $2,776 of CERs. Overall, the construction industry in Honduras needs to incorporate life cycle assessment and handprinting into infrastructure projects. Using cement options with less CO2 emissions in projects would be a key step for all projects to incorporate. Additionally, Central America needs to have a publicly available database with environmental impacts from construction materials used in the region.