In Wasteful Earth Hour?, it's claimed that candles emit roughly 10 times the carbon dioxide of light bulbs of the same brightness. While emissions will vary depending on the candle, the lightbulb and the electricity source, is this claim more or less correct?
Although I do not agree with the statement here is a link that explains mathematically how some people got to this particular ratio.
The writer takes into account the carbon dioxide emitted by a candle and the carbon dioxide that is emitted by the electricity that powers a light bulb with the same luminosity.
In my opinion the calculation is not complete since it leaves out the energy needed to manufacture a light bulb. We should make comparisons taking into account the overall carbon dioxide footprint.