[pragmar]

The CO2 is going back into the atmosphere regardless, if the wood is not burned, it will decompose.

[kelnos]

Sure, but the CO2 from burning wood goes into the atmosphere right now. The CO2 from decomposing wood goes into the atmosphere over time, sometimes even over the span of years, depending on environmental conditions.

And, regardless, it's not like we only burn wood that's starting to decompose. Quite the contrary.