Carbon trading standards (or the lack of them)

Today on the radio, someone was complaining that patio heaters are bad for the planet ... a luxury which was emitting CO2 ... put away the patio heater and put on another jumpers was one piece of advice. But then came a statement from Calor Gas who claimed that a patio heater used 35 times LESS energy than a mobile phone charger. At 15KW for the patio heater that would have to be a mighty mobile phone!
Time for some sums. My phone charger is rated at 4.9V, 450mA which is about 2.2W. The phone only takes a few hours every week to charge, so that's 0.23KWh energy expended (and an overestimate as the battery will not be drawing this for all of the time). Say the heater is used 10 times a year for 2 hours then that's 300KWh. Even if the calculation is based on a charger delivering full charge for every minute of the day for a whole year (which is wildly unreasonable), this still only gives 19.2KWh, which is still 15 times less than the patio heater.
So the comparison is absurd. But I expect folks down the pub will be saying .... I'm getting rid of my mobile phone now and buying a patio heater ... much better for the planet!