Sone numbers and stuff over here:
http://enochthered.wordpress.com/2008/03/31/earth-hour-candles-and-carbon/Cliffs-notes: It takes 40 candles to produce as much light as a single 40W bulb and at a worst-case scenario that will produce about 10 times as much CO2 emissions.
Of course, you probably do not light 40 candles, but instead read your book in insufficient light, ignoring any good advice from your optometrist. So if you only used about 4 candles (and use coal to generate electricity), you would break about even. However, that referred calculation does not include emissions from production and transportation of the candles, which I assume are considerably higher than that of light bulbs, due to their reduced life spans.
Then again, to quote
Comeau: Fuck politics. I just want to burn shit down.