A hilarious blunder in my previous article about candles has me out by a factor of 10 on the calorific value of candles. In that article I said wax has about the same calorific value as butter, 3 kJ/g. It turns out that the calorific value of butter is about 30 kJ/g. Oopsie.
That means one modest candle burns at 75 W (not 7.5) and four candles burns at a whopping 300 W! So if you lit any candles then you were probably emitting more carbon than the “business as usual” scenario of having a couple of lights on.
This more or less confirms my prejudices that Earth Hour was a pointless and futile gesture so you could be seen to do something, without actually having to bother to go carbon free.