And by that, I don't mean I'm against the economical sustainable use of forest -- forest should be used as much possible as is sustainable to limit carbon dioxide emissions. The problem is, there's not enough forest, unless you cut 100% of rainforests on Earth and replace them with oil palm plantations.
Let us assume that there is a population that uses firewood. Wood that can be
burned grows 0.1 zettajoules per year. The population uses less firewood than
0.1 zettajoules per year. Sustainable? Yes, except read on...
However, the population grows and due to simultaneous economic growth per
capita, energy consumption increases to 0.5 zettajoules per year. Seeing that
the limits of growth and sustainability are near, it has become trendy to burn
firewood instead of burning coal, and it has also become trendy to own forest.
However, no matter how much people want to burn firewood, it cannot be burned
sustainably more than 0.1 zettajoules per year. Thus, by burning firewood
(regardless of whether you own forest or not), you are increasing the price
of firewood due to laws of supply and demand, which causes somebody who can't
afford firewood anymore or just doesn't care enough to stop burning firewood
and start burning coal.
Also, no matter how much people want to own forest, not everyone can own so
much forest that it would cover their energy consumption. By buying and owning
forest (regardless of whether you burn the wood or sell it to somebody else),
you are increasing the price of forestland due to laws of supply and demand,
which causes somebody to sell it and use the money for something else, thus
ceasing to be forest-owner. Not everyone can own enough forest.
The marginal energy is provided by coal. Forest owners won't all decide to cut
their forest immediately, but coal mine owners are more than happy to sell some
of their limited coal reserves to you. Forestry is sustainable, coal mining is
The important thing to understand is that everyone is using marginal
energy. Marginal energy is coal. Thus, every kWh of electricity used, every
MJ of heat produced, etc. effectively comes from coal.
In a hypothetical future world, marginal energy could be supplied sustainably by advanced
small modular nuclear reactors (by that, I mean fission breeders, not fusion), or perhaps even wind power stored in hydrogen or batteries.
However, today marginal energy comes from coal, and thus every energy user is
effectively using coal.
If you reduce your energy use by 1 MJ, you reduce coal use by 1 MJ. It's as
simple as that.
Also, needless to say, sawlogs shouldn't be burned; they should be used for
constructing houses. Pulpwood could perhaps be burned, but a better option is
to bury it. Unfortunately, there are no economic incentives for burying wood.
Wood is a very dirty fuel. If you bury 1 MJ worth of wood underground and burn
1 MJ worth of coal, less carbon dioxide is produced than would be produced by
burning the 1 MJ worth of wood directly -- for the same energy output. In fact, wood is probably the dirtiest
fuel of them all, very likely dirtier than peat. Let's bury the wood and burn the best and cleanest of the fossil fuels,
natural gas! And perhaps some oil in airplanes and heavy trucks that use jet fuel or diesel, respectively, and have no viable replacement like electricity.
Disclaimer: I own 25.6 hectares of boreal taiga forest. It's an
excellent investment even in these northern latitudes. If you can, consider
investing in forest!