I have seen mt used as an abreviation of 'metric tonne' Still wrong.
John F-L
----- Original Message -----
From: "Bill Hooper" <hooperb...@bellsouth.net>
To: "U.S. Metric Association" <usma@colostate.edu>
Sent: Saturday, September 26, 2009 3:58 PM
Subject: [USMA:45901] Re: Greenhouse Gas Reporting
On Sep 26 , at 9:16 AM, Jason D Darfus wrote,
regarding reports on emissions of greenhouse gases:
The symbol mt (militon) is the same as a kilogram and could possibly
be interpreted as such (oops!)
Quite right!
Actually, it not only COULD be, but actually SHOULD be interpreted to
mean "millitonne" since the SI symbol for tonne is "t" and the SI
prefix "m" means "milli-" or one-thousandth. Thus, the maverick "mt"
really does mean a kilogram (not the million kilograms the authors
apparently meant).
Made up symbols that uninformed people invent willy-nilly to suit
narrow, specific purposes can always be misinterpreted and can be
misinterpreted in many different ways (sometimes in ways that are more
SI correct than the intended meaning). That is why they should not be
used.
That's the whole point of objecting to "mt" as a symbol in this case.
There is a proper name and symbol for everything in SI and it should
be used. In SI, the symbol for million tonnes is Mt (not mt) and the
version expressed in kilograms is gigigram, whose symbol is "Gg". In
no case should the unit symbol be appended with CO2e or any other
qualifiers.
Bill Hooper
"72 millitonnes body mass" (ha, ha!)
Fernandina Beach, Florida, USA
