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Concrete In Australia : March 2013
Concrete in Australia Vol 39 No 1 45 Understanding the carbon footprint of precast concrete: A case study from the concrete pipeline systems sector* Martin Clarke -- Chief Executive, British Precast Concrete Federation Dr Ha z Elhag -- Product Association Manager, British Precast Concrete Federation e last few years saw a rush of "Carbon Footprint" data and a considerable increase in methodologies and standards dealing with emissions associated with global warming potential. e number of industry online "carbon calculators" has increased considerably. With the lack of a clear methodology (and wrong handling of data and conversion factors) there is a risk that many of the tools currently available fail to offer a proper understanding of the true carbon footprint of concrete. is paper identifies the composition and range for precast concrete products "Carbon Footprints" and looks at how misperceptions and inappropriate handling of secondary data in the sector can lead to wrong conclusions. A case study, based on a recent concrete pipe carbon footprint study and how it compares with alternative types of pipe made of plastic, is used to explain the risk associated with these misperceptions. 1.0 INTRODUCTION e case for UK concrete businesses to develop and improve their products carbon footprints is very clear and strong. e last five years saw a rush of carbon dioxide emissions information and a considerable increase in methodologies and standards dealing with emissions associated with global warming potential. e UK government established an entire department to deal with the issue of Climate Change and there are already some targets set on the national and construction industry level. Businesses in the UK are targeted by a range of schemes and measures designed to reduce overall emissions contributing to Climate Change. ese include schemes such as the EU Emissions Trading Scheme, the Carbon Reduction Commitment (CRC) energy efficiency scheme, the Climate Change Agreement (CCA) and the energy-associated Climate Change Levy. Tools based on products Environmental Product Declarations (EPD) in the UK, such as BRE s Green Guide to Specification, are becoming influential in the market and many authorities in the civil sector, such as the UK s Highway Agency and Ofwat, are making greenhouse gas emissions and carbon footprinting central to their sector s construction procurement decisions. A simplistic example that can demonstrate the popularity of the subject worldwide is by identifying the number of results yielded from a search of terms using the Google worldwide web search engine: A simple search for "Carbon Footprint" yielded 9,140,000 results. is is compared to 2,910,000 results when searching for another common term "speed cameras", 5,630,000 results when searching for "Julia Gillard" or 3,730,000 results for "Sydney Opera House". However, despite all the increasing attention on this subject there is still no unified strict methodology for the calculation of "carbon footprints". e term is not mentioned or defined in any recognised standards (although this is set to change with the publication of ISO 14067 parts 1 and 2). e most widely used definition to date, "... a methodology to estimate the total emission of greenhouse gases (GHG) in carbon equivalents from a product across its life cycle" (Carbon Trust, 2007), seems to compromise the "System boundary" concept of ISO 14044 (BSI, 2006): the Life Cycle Assessment (LCA) specification standard which is one of the core standards currently used to structure carbon footprinting study methodologies. Even the use of the word "footprint", which is thought to be coming from the older term "ecological footprint", has been questioned by academics (Hammond, 2007; Weidmann & Minx, 2008). All this has led to a considerable level of confusion within the industry with various studies and databases quoting different carbon footprints for products. However, the main caveat for the users of carbon footprinting data within the construction industry is casting decisions based on secondary data obtained from databases without proper data quality assessment or sensitivity and consistency checking. One of the most illustrative examples for this caveat can be found when examining concrete and plastic pipe carbon emission claims and existing literature. 2.0 FACTORS AFFECTING THE CARBON FOOTPRINT OF CONCRETE PRODUCTS roughout the last 10 to 15 years there have been a considerable number of academic and commercial studies, reports and publications identifying greenhouse gas emissions * is paper was first presented at Concrete 2011, the conference of the Concrete Institute of Australia. It is republished with permission.