An average TV on standby for 19 hours
CO2e: 0.12 Kg (2 hours)
http://www.tvec.org.uk/Energy_calc_2.asp give
TV, 49watts (on), 13 watts (standby)
For CO2 from electricity we have 0.1 Kg per megajoule
Assume TV on standby is 13watts. 19 hours is 72000 seconds.
Electrical energy is 13 * 72000 joules or 1.15 megajoules.
This creates 0.12 Kg CO2.
But for several different answers see http://uk.answers.yahoo.com/question/index?qid=20070716040535AARuwNB&show=7