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How Was Your Carbon Footprint Calculated?
General Information The GRC-Pirk carbon calculator determines carbon dioxide and other greenhouse gas emissions for shop operations. The following information explains how emissions are calculated. A carbon footprint is a measure of the impact our activities have on the environment, and in particular climate change. It relates to the amount of greenhouse gases produced in our day-to-day lives through burning fossil fuels for electricity, heating and transportation etc. The carbon footprint is a measurement of all greenhouse gases we individually produce and has units of tons (or Klbs) of carbon dioxide equivalent. A carbon footprint is made up of the sum of two parts, the primary footprint (shown by the green slices of the pie chart) and the secondary footprint (shown as the yellow slices). 1. The primary footprint is a measure of our direct emissions of CO2 from the burning of fossil fuels including energy consumption and transportation (e.g. car and plane). We have direct control of these. 2. The secondary footprint is a measure of the indirect CO2 emissions from the whole lifecycle of products we use - those associated with their manufacture and eventual breakdown. To put it very simply ? the more we buy the more emissions will be caused on our behalf. Reporting Greenhouse gas emissions are typically reported world wide in metric tons. Carbon dioxide emissions are calculated from the weight of carbon. Other emissions, such as methane and nitrous oixde, are reported in carbon dioxide equivalents so that the emissions can be compared. Short tons (equivalent to 2,000 lbs) are the units used to report emissions in this calculator. One metric ton can be converted to short tons by multiplying the total by 1.1023. References to "CO2 emissions" or "carbon emissions" typically include emissions from all greenhouse gasses. Emissions Calculations For this calculator, emissions attributed directly from shop operations, as well as indirect emissions, such as the CO2 emitted in manufacturing paint, are included in the overall emissions calculation. Total Emissions In 2004, the United States emitted 7074 million metric tons of carbon dioxide equivalent green house gasses[1]. This equates to 27 tons per employee[2]. In this calculator, direct emissions (calculated from shop energy use and waste) make up 45% of the total U.S. emissions, with the remaining 55% representing indirect emissions. To determine the indirect emissions for each shop, we apply an indirect emissions factor to all shop operations. This is simply the ratio of total U.S. CO2 emissions to the total emissions for the shop operations we are considering. The emissions for specific behaviors included in the calculator are documented below. For the specific operations evaluated in the calculator, we rely on data regarding typical consumption to determine an average contribution. In most cases, we also calculate high and low endpoints for each operation. These three points are used to frame the specific responses for each item. For example, we used data from industrial energy surveys to determine the average maximum emissions for a shop that has not implemented energy saving measures and the average minimum for a shop that has implemented many energy savings measures. Shop Energy Shop energy emissions are based on U.S. averages for SIC code 7500. State is used to determine carbon dioxide equivalent emissions per kilowatt hour of electricity[3] and climate zone[4] which affects heating and cooling energy usage. Heating & Cooling Average: Shop type and number of spray booths are used to determine energy consumption and geographic location is used to scale heating and cooling consumption.[5 Behaviors: Data from industrial consumption surveys asking about adequacy of insulation, occurrences of drafts, and thermostat settings was used to determined high and low end usage of space heating. Data about frequency of air conditioning usage was used to determine high and low end consumption rates[6]. Choosing "Wherever possible" reduce energy emissions by 16%, "In some areas" is the average response, and "Very little" increases emissions by 13%. Lighting Average: On average lighting contributes 54% of all shop electrical usage for non-heating and cooling purposes.[7] Behaviors: CFL's use 2/3 less energy than standard incandescent bulbs[8]. The response, "Everywhere possible", reduces the lighting contribution of electrical consumption for lighting by 2/3, and the "In some lights" response reduces consumption for lighting by 1/3. Equipment Average: Equipment, i.e., Spray Booths, Printers, Air Compressors, Motors, etc., typically contribute 46% of all shop electrical usage for non-heating and cooling purposes. Behaviors: ENERGY STAR equipment can save anywhere from 10% to 50% in energy usage over conventional equipment. Energy management controls can reduce electric consumption up to 50% for these devices. Water Average: Water consumption is determined from shop type and number of spray booths[11]. Behaviors: Energy from hot water can be saved by reducing the hot water thermostat, adding insulation to the tank and installing low-flow devices. This data was used to determine average high end and low end consumption rates[12]. Choosing "As much as possible" reduce hot water emissions by 38% and "Somewhat" by 14%. Driving Emissions from driving employee vehicles and serviced vehicles are included in the calculator, but emissions from public transportation are omitted. Average: Emissions factors are determined based on standard sedan automobiles and then multiplied by a statistical number of miles driven per facility square footage, assuming gasoline-based vehicles[13]. Recycling & Waste Average: 246 million short tons of waste were land filled in 2004[20]. This produces 2.1 tons of carbon dioxide equivalent greenhouse gases per year per employee[21]. Behaviors: Recycling shop trash can reduce your overall waste stream, and thus emissions by 42%[22]. Composting can reduce emissions by 24%[23]. Results Averages are based on US EPA Inventory of Greenhouse Gas Emissions and Sinks[24] and behavior emissions (savings or additions) are determined from the answers supmitted. World average for greenhouse gas emissions are 3.2 billion metric tons carbon dioxide equivalent. This equates to 5.5 short tons per employee[25]. Sources
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