Global warming is considered as the impacts of human activities on the climate (Houghton, 2005). The temperature increases observed since the middle of last century have resulted from the increases of greenhouse gas emissions (Eckard, 2010). As the issues of health problem and nature disasters draw more and more attention, GHG emissions reduction becomes a key issue in every walk of life, from politics to business. According to the latest data from Environment Canada, the construction industry contributed to around 1.4 Mt CO2e annually between 2005 and 2011 (Environment Canada, 2013). Although, it accounts for only 1.7% of total Canadian GHG emissions in 2011 (Environment Canada, 2013), this ...view middle of the document...
The guidance document will be developed through document analysis, literature review, questionnaire and interview, in order to make the guidance document cost-effective and applicable for construction companies in Waterloo Region. The specific objectives of this project are to:
Objective 1: Determine the accounting tool of GHG emissions.
Objective 2: Identify existing practices for GHG emissions reduction in the construction industry.
Objective 3: Finalize best practice guidance for local construction companies.
II. Background and Context
2.1 Scope of this study
2.1.1 Definition of GHG
According to the Kyoto Protocol to United Nations Framework Convention on Climate change, GHG embraces six gases that are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydro fluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). Since the latter three are not usually found in the construction industry (Yan et al, 2010) and CO2, CH4 and N2O accounts for 98.7% of the entire GHG emissions (Environment Canada, 2013), GHG mentioned in this study only refers to CO2, CH4 and N2O.
2.1.2 Sources of GHG and Division
Based on mass lit reviews, GHG emissions in construction industry are mainly from following sources: manufacturing of building materials, transportation of materials and equipment, transportation for employees, energy consumption of on-site equipment, disposal of waste (Core, 1998; Guggemos, 2005; Upton, Spinney & Heath, 2008). Because the target readers of best practice guidance are construction contractors, this study will not consider the material aspect. Instead, GHG emissions from stationary sources should be looked into because those contractors or designing companies all have offices, which consume considerable energy and generate GHG emissions (B.C Ministry of Environment, 2013).
Therefore, this study will focus on GHG emitted from transportation for workers, transportation of equipment, energy consumption of equipment and stationary sources and waste disposal. The divisions of those GHG sources are 3 aspects that are transportation, on-site uses and office work.
2.2 Accounting tool of GHG Emissions
In order to convince construction companies to take practices to reduce GHG emissions, the first thing is to provide accounting tools of GHG emissions, so that they can have better realization about they performance of GHG emissions. Typically, process-based method is often used for calculation for environmental impact, including GHG emissions. Process-based method establishes models of different activities related to a service or a product considering process flow diagram (Yan et al, 2010). Although process-based method has lots of problems, like hard to define the boundaries and difficult to conduct in small and medium enterprise (SME), it remains the most popular method to measure GHG footprint (Bennett, James & Klinker, 1999). Moreover, environmental input-output analysis is an alternative approach process-based...