There has long been controversy around wood-burning stoves - but till more recently it didn't revolve around greenhouse gas emissions, how 'clean' in terms of carbon dioxide wood burning is, or whether they might face a ban in the race to net zero. Previously it was about the pms. The particulate matter.

This element of the issue is one that historical geographer, Fraser MacDonald, dug into a year ago in a very eloquent essay in the London Review of Books, titled Burning Questions: Home fires. 

Following the introduction of New Build standards that were widely seen, or misconstrued, as auguring a ban, on wood-burning stoves, Dr MacDonald talked about the issue again.

"We need," he said, " to separate out two things: CO2 emissions and pm 2.5. Most of the debate UK-wide and indeed worldwide is about the latter. Why? The CO2 emissions of fuel stoves are probably modest compared to most controllable sources, but pm 2.5 air pollution really foreshortens life (attributable UK deaths by one estimate were similar to Covid in 2022)."

Domestic combustion, he observed,  is a primary source of pm 2.5. "Governments, quite properly, have a responsibility to monitor and improve public health – the health and social care cost of air pollution is estimated to be something like £1.1 billion per year in Scotland."

On pm 2.5 there is some positive news. Dr MacDonald said:  "You wouldn’t know it from a lot of the reporting but the long term trend of pm 2.5 has been dramatically downward since 1970.  But as pm 2.5 has decreased, the relative contribution from domestic combustion has increased – it accounts for 29% of UK pm 2.5 emissions.

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"But even this total amount from domestic combustion is declining: four out of five recent test sites show this and the most likely explanation is because efficient modern wood stoves are replacing older stoves or open fires.

"This isn’t obvious from news stories. Many news reports talk about ‘wood burners’ next to a picture of a stove, without making clear that much of the pollution data often does not disaggregate between types of stove, nor between stoves and open burning.  So when science journalists often talk about ‘wood burners’ this literally means people who burn wood, not the appliances that burn wood. That’s very confusing."

After he wrote Burning Questions, he noted,  a reader shared an unpublished National Atmospheric Emissions Inventory dataset which he then requested and was sent

The Herald: Logs burn on a wood burning stove.

"What it shows is that 80% of our pm 2.5 problem in the UK is NOT from stoves. It’s from open burning, in other words people burning wood in open fireplaces, but also in beach bonfires, BBQs, boutique firepits, chimineas, and the like. When it comes to burning in open fires this is often being done in Smoke Control Areas – zones where this has already been prohibited. So why do stoves get the attention when the problem lies elsewhere? And why the confidence that regulating stoves will fix the problem when the Clean Air Act plainly hasn’t?"

Dr MacDonald is not dismissive of pollution from smoke and its impact on human health - he regards it as a real problem. 

" I understand," he said, "why many people are angry that their health is compromised by people burning wood. But I think we should tackle first things first – the open burning which accounts for 80% of the problem."