<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;">Eric,<div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><br>In the United States, the climate change policy community started using carbon equivalents (specifically, MMTCE or million metric tons of carbon equivalents), following the practice of the scientific community, which still often talks in terms of carbon instead of CO2.<br><br>While I was lead author of the U.S. greenhouse gas inventory we switched from MMTCE to Teragrams of CO2 to be consistent with international reporting and for much of the domestic policy communications (it also saves the conversation of CO2 to carbon when dealing with non-CO2
emissions when expressed on a GWP-weighted basis). However some groups within the United States continue with the old practice and even discuss emissions in terms of short tons or pounds instead of metric tons.<br><br>There is certainly
no advantage to using carbon instead of CO2. And I would say that for policy purposes that the international convention is to report in terms of CO2 equivalents.<br><div> <br>michael<br>[moderator]<br></div><span style="font-family: symbol;"></span><font size="2"><br style="font-family: arial,helvetica,sans-serif;"></font><hr style="width: 100%; height: 2px; font-family: arial,helvetica,sans-serif;"><font style="font-family: arial,helvetica,sans-serif;" size="2">Michael Gillenwater<br>Princeton University<br><a rel="nofollow" target="_blank" href="http://www.princeton.edu/%7Estep/">Science, Technology and Environmental Policy Program</a><br><br><a rel="nofollow" target="_blank" href="http://www.ghgnetwork.org">GHG Experts Network</a> <span style="text-decoration: underline;"></span><span style="color: rgb(0, 128, 255);"></span> (Executive Director)<br><a rel="nofollow" target="_blank" href="http://www.ghginstitute.org">GHG Management
Institute</a> (Dean of Institute)<br><a rel="nofollow" target="_blank" href="http://www.ert.net">Environmental Resources Trust</a> (Director of Verification Policy)<br><br>Tel +1 202 997 3335<br>Skype: mwgillenwater<br><a rel="nofollow">gillenwater@alum.mit.edu</a></font><font size="2"><span style="font-family: arial,helvetica,sans-serif;"> </span></font><br style="font-family: symbol;"><span style="font-family: symbol;"></span><hr style="width: 100%; height: 2px;"><span style="font-family: symbol;"></span><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><br><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;">----- Original Message ----<br>From: Eric Mehlhoff <emehlhoff@cameron-cole.com><br>To: discuss@ghgnetwork.org<br>Sent: Thursday, October 25, 2007 5:59:38 PM<br>Subject: [GHG Network] Carbon equivalent vs. Carbon Dioxide equivalent<br><br>
<br>Dear Colleagues,<br><br>I am interested to understand the differences in carbon equivalents and
carbon dioxide equivalents. <br><br>>From my initial hunt, it appears that carbon equivalents are almost
exclusively used in the US (EPA and some voluntary programs), but
instances seem to taper off around 2003-2004. <br><br>Does anyone have a good sense for the origin in using carbon
equivalents as a metric, and is this metric still being used commonly or has it
now been completely surpassed by the carbon dioxide equivalent? <br><br>Is it more common to see carbon equivalents in sequestration projects? <br><br>Is there any advantage to using carbon equivalents over carbon dioxide
equivalents (These metrics are completely interchangeable anyway)?<br>_______________________________________________<br>Greenhouse Gas Inventory Experts Network<br><a rel="nofollow" target="_blank" href="http://www.ghgnetwork.org">www.ghgnetwork.org</a><br><br>To post message:<br>Discuss mailing list<br><a rel="nofollow" ymailto="mailto:Discuss@ghgnetwork.org" target="_blank" href="mailto:Discuss@ghgnetwork.org">Discuss@ghgnetwork.org</a><br><br>To unsubscribe:<br><a rel="nofollow" target="_blank" href="http://milkyway.forumone.com/mailman/listinfo/discuss">http://milkyway.forumone.com/mailman/listinfo/discuss</a><br></div><br></div></div></div><br></div></div></body></html>