[m-i-l]

> The whole "carbon neutral" think is a crock. Coal is, after all, just dead trees, so coal plants run on "biofuel" and are "carbon neutral".

The difference is in the timeframes for capture and replacement - with coal it is millions of years, and with wood it is years. That means burning coal releases carbon which was trapped millions of years ago, and it would take millions of years to trap equivalent amounts of carbon with the formation of new replacement coal deposits. Burning wood on the other hand releases carbon that has been trapped within our lifetime, and it is easy to replace with new trees grown in our lifetime. Bear in mind that if we reverse millions of years of carbon capture we would revert the atmosphere to what it was like millions of years ago, and time travellers visiting that era are likely to need breathing equipment.

[ppf]

True, but what is a sustainable level of tree harvesting to feed the world's energy needs?

[eloff]

That's not possible, our energy needs are too great for that now. But nobody would seriously suggest wood (or other biofuels) be our principal energy source anyway.

[ppf]

That's my point. Any scheme involving burning wood to create aviation fuel is an indicator that the wrong side of the energy usage balance is being addressed.