Carbon footprint analysis of construction activities in Sri Lanka: an input-output table

Abstract

The construction industry is one of the major contributors that emits carbon into the environment. When considering the carbon emission in the local context, even though there are Input-Output Tables (IOTs) that applies to all types of industries in Sri Lanka, there seems to be limited focuses on IOTs specifically relating to the construction activities which is vital for the need due to its outstanding contribution to the carbon footprint of Sri Lanka. Hence, this study aims to calculate the carbon footprint construction activities in Sri Lanka using IOT with a bottom-up approach. The required data were extracted from published documents of Survey of Construction Industry by Census and Statistics, and The Inventory of Carbon and Energy (ICE) database of UK. Carbon footprint of construction activities were calculated using IOT with a bottom-up approach. The analysis revealed that the road and railway sector have the highest contribution of 48% to the monetary value of the construction industry meanwhile it accounts for 44% of the highest carbon emission to the atmosphere in the year 2020. Subsequently, activities related to non-residential residential, and utilities contribute to 20%, 15%, and 12% of total carbon emission respectively. In terms of construction materials, cement-based activities (59%) were the highest contributor while rubble and metal-based (23%), and iron and steel-based activities (17%) were next level contributors to the carbon emission due to construction. The analysis concluded that the as the initiatives, public sector projects including road and railway sector and utilities should integrate more sustainable construction practices as they are responsible for more than 50% of carbon emission.