Follow up to Earth Hour

H/T Tim Fowler

Earth Hour, candles and carbon

There's one thing in particular that bothers me about Earth Hour - these people who electric lights and then go and light up candles, and think that they're helping do something about anthropogenic forcing of climate change.

The widespread practice of misguided eco-Luddites turning off their lights for Earth Hour and burning candles as a source of light is grossly misguided and actually contributes to increased carbon dioxide emissions.

Yes, I know candles are nice and romantic - but you're taking paraffin wax, in the form of a candle, and burning it, very inefficiently, at a low temperature. This stuff is pure hydrocarbon - it's a heavy alkane fraction distilled straight off crude oil. This stuff is getting so scarce that nations are prepared to go to war just to secure it, remember?

A candle flame burns at a low temperature - so it's a thermodynamically very inefficient source of energy - and most of the energy released in a candle is wasted as heat, anyway.

Even if 80% of your electricity comes from coal and fossil fuel fired power stations, as it does in Australia, burning candles is very polluting and certainly very greenhouse gas and carbon dioxide emissions intensive, even more so than electric lighting...

...Therefore, for every candle that is burned to replace electric lighting during Earth Hour, greenhouse gas emissions over the course of the one hour are increased by 9.6 g of carbon dioxide.

If the light output from a 40 W light bulb was to be completely replaced by candles, this will lead to the emission of an extra 295 grams of carbon dioxide per over simply using the electric lights - if the equivalent of one thousand 40 W bulbs are replaced by candles, that's an extra 295 kilograms of CO2 emitted.

In places where a greater proportion of the electricity supply is generated by nuclear energy or hydroelectricity, this increase in greenhouse gas emissions is even larger.

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