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<FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Dear Thomas:<BR>
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There is often a trade-off between accuracy and user-friendliness with such calculators, but I appreciate your intent.<BR>
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In (3) Nice try, and works well enough on average, but ignores (for any particular flight) winds aloft, diversions, holds, taxi delays, and seasonal variables.<BR>
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In (4) Good. Although I do wonder if it’s “fair” to allocate emissions on the basis of passenger weight plus baggage vs cargo. The aircraft and its flight exist chiefly for passenger air travel, a lot of aircraft weight is carried around for their comfort and safety (water, food (when it exists), toilets, stewards, seats, entertainment system, air circulation and other equipment, etc.).<BR>
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In (5): Sweet.<BR>
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In (6) I would think other categories have similar variable occupancy: day vs night flights, for example, or aircraft size, or nation of registry. Why operator?<BR>
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In (7): we (Climate Mitigation Services for City of Aspen Green Tags air travel calculator: www.aspenzgreen.com/offsets_calculator_air_calculated.cfm ) also included an optional RF multiplier, found the oft-used 2 to 2.5 x as out of sync with the more recent scientific assessment, and use RF of 1.89 times fuel emissions. But we exempt all flights shorter than 200 statute miles on the basis that RF relates to flights at higher altitudes than such short flights typically operate.<BR>
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Overall: How many passengers actually know what aircraft type they flew on? Who is your user audience? If the general public, then you might be assuming too much in some cases.<BR>
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I would like to review the full description, thanks. All the best, -Rick-=<BR>
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PS: I am currently working on a private and business aircraft fuel and emissions calculator.<BR>
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Richard Heede <heede@climatemitigation.com><BR>
Climate Mitigation Services<BR>
1626 Gateway Road<BR>
Snowmass, CO 81654-9214 USA<BR>
1-970-927-9511 office<BR>
1-970-343-0707 mobile<BR>
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On 12/3/07 5:56 PM, "Thomas Tomosky" <Thomas.Tomosky@trx.com> wrote:<BR>
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</SPAN></FONT><BLOCKQUOTE><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Greetings. I am new to the Greenhouse Gas Experts Network, and would like to introduce myself and the project I am working on. <BR>
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My name is Dr. Thomas Tomosky and I am the Application Manager in the Travel Analytics group at TRX. One of the projects I am working on is a CO2 emissions calculator for air travel. We attempted to build this calculator in as detailed and accurate manner as possible. We decided to make the calculator and the underlying calculations transparent, so that interested parties can examine the details. The calculator has been externally verified by ICF International, a leading energy and environmental consulting firm. You can view the basic calculator at <a href="http://carbon.trx.com.">http://carbon.trx.com.</a> <BR>
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What follows is a very brief description of our basic Leg Level CO2 emissions calculator. The full description is available upon request. There are 8 major steps, the last 2 steps being optional. They are:<BR>
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</SPAN></FONT><OL><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Gather airline schedule data – city pair, number of miles, operating carrier, aircraft, and number of seats. We use schedule and fleet information from OAG Back Aviation Solutions.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Determine fuel burn rates for aircraft and distance. We obtain fuel burn rate information from the 2006 version of the EMEP/CORINAIR Emission Inventory Guidebook. This data includes both LTO and cruise fuel burn rates.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Calculate total CO2 emissions for the flight. We use interpolation methods to accurately determine the amount of fuel burned, and CO2 emitted, for a particular aircraft for a particular flight.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Allocate emissions between cargo and passengers. From the US DOT, Bureau of Transportation Statistics, we determine the amount of cargo (freight and mail) that scheduled passenger flights transport. Based on weight percentages, we allocate the CO2 emissions between cargo and passengers.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Allocate emissions per cabin. Based on passenger seat pitch and width data obtained from www.SeatGuru.com <a href="http://www.SeatGuru.com"><http://www.SeatGuru.com></a> , we can determine the amount of “real estate” taken up by a passenger’s seat in each cabin. The greater the real estate, the greater the emissions allocated to a seat in that cabin.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Adjust for passenger load factors. Typically, airline flights are not 100% full, so we adjust emissions for the average number of passengers for that carrier.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Adjust for RFI (optional). We allow web users to adjust for the Radiative forcing Index or not, depending on their particular needs.
</SPAN></FONT><LI><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Calculate cost of CO2 emissions (optional). Since the cost of CO2 emissions is highly variable, we provide web users with information on the various emission offset options and trading markets and give them the ability to adjust the cost per metric ton of CO2 to suit their needs. <BR>
</SPAN></FONT></OL><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>For our corporate clients, we go a few steps further than the basic Leg Level calculator on the web. In our Enterprise Level calculator, we take a client’s air travel footprint for a period of time, normally a calendar year, and analyze it in detail. We quantify the amount of CO2 emissions, and we compare those emissions with the emissions resulting from the use of the “greenest” carrier for each city pair and to an “average” corporate travel footprint. We recommend and quantify ways of reducing CO2 emissions by reducing travel, booking the greenest carriers, and eliminating unnecessary connections. For client trips that are not on scheduled non-stop flights, we employ a proprietary algorithm which builds reasonable connections between city pairs. This is important since connections can use different equipment, have different fuel burn rates, number of seats, and so on.<BR>
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If you have comments on our model, or are interested in learning more, please contact me or our VP and General Manager, Scott Gillespie. We are especially interested in new data sources which can further improve the accuracy of our model. I can be contacted at thomas.tomosky@trx.com or at 724-924-6070. Scott can be contacted at scott.gillespie@trx.com or at 440-248-4111. <BR>
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Thank you.<BR>
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Tom<BR>
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</SPAN><FONT SIZE="4"><SPAN STYLE='font-size:13.0px'>Thomas K. Tomosky, Ph.D.<BR>
Application Manager, Travel Analytics<BR>
TRX<BR>
2175 Princeton Road<BR>
New Castle, PA 16101 USA<BR>
www.trx.com <outbind://25-00000000EF3469787771D511AE2200508BC9E1260700AFAEC7F33CBBD411AE1300508BC9E12600000126423E0000F66965CFA3FB824D837B89B38F04EEF7000000B8F4C80000/www.trx.com> <BR>
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email: <FONT COLOR="#0000FF">thomas.tomosky@trx.com</FONT> <a href="mailto:thomas.tomosky@trx.com"><mailto:thomas.tomosky@trx.com></a> <BR>
office: 724-924-6070<BR>
fax: 724-924-2867<BR>
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</SPAN></FONT></FONT><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>****************@*******************<BR>
Richard Heede <heede@climatemitigation.com><BR>
Climate Mitigation Services<BR>
1626 Gateway Road<BR>
Snowmass, CO 81654-9214 USA<BR>
1-970-927-9511 office<BR>
1-970-343-0707 mobile<BR>
<BR>
<°){{{{>< <°){>< <°){{{{>< <BR>
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