A recent Telegraph & Argus article outlined the progress the Council had made with the introduction of wood-fuelled boilers, in City Hall and Ilkley Town Hall, as part of the programme to use renewable energy sources and cut down on CO2 emissions.

The Forestry Commission is keen to see the practice spread, and there was mention of a renewable heat incentive scheme to help with the installation of more wood burners.

However, an article in another publication, quoted by the Sustainable Building Association, suggests that “wood burners are an expensive way of making climate change worse and reverse more than a century of public health improvement”.

They can’t both be right, and it could be that the simple statement that burning wood is neutral in terms of producing CO2 – because the trees only release the CO2 that they take out of the atmosphere as they grow – may be less than the full story.

It’s always seemed preferable to use wood, made of CO2 from the current atmosphere, rather than coal, gas and oil, made millions of years ago and importing ancient CO2 into our present-day atmosphere. Closer inspection suggests it’s not quite so straightforward.

The first problem is that wood, and most other forms of biomass, are not low-carbon fuels, as like coal they are made predominantly of carbon.

In fact, wood produces twice as much carbon dioxide as gas when used as a fuel, mainly because gas burns hydrogen as well as carbon.

It follows that for a given amount of energy it is preferable to use gas and keep the tree alive and storing carbon as it grows.

There’s also the problem that while the tree may have taken many decades to abstract carbon from the atmosphere, when it is burned, all the CO2 is returned to the atmosphere in a matter of minutes.

Additionally, there is probably more CO2 produced by the transport of the fuel from greater and greater distances as the local wood is used up, and we should remember that a shortage of wood was why we turned to coal in the 17th century.

Importing wood pellets from the US to burn at Drax, or in our school boilers, produces more CO2 than some alternatives.

The answer is to concentrate on energy-efficient homes, insulated to the highest standard with the small amount of heat required from ground-source heating.

Rather than cutting trees to burn, we should plant more, keep them alive to store carbon in their wood and roots, and then follow the US and Scandinavia in building our houses from wood, so keeping the carbon in them out of our boilers and the atmosphere for decades to come.