Humans and fire have co-evolved. But on a planet experiencing catastrophic heating, what place does fire have as a source of heating?
Last year’s Storm Éowyn reopened a debate across rural Ireland about the importance of having the means to heat homes during an electricity blackout. Households without chimneys found themselves without electricity for up to a fortnight and could not even light a fire to keep themselves warm.
Although our building regulations do not explicitly rule out chimneys, the heating source – heat pump, oil or gas heating – in a well-insulated and airtight building will be much more efficient and cost less to run if there is no chimney. After all, an unused, open chimney can lose up to 30 per cent of a home’s heated air – and up to 90 per cent of the heat from an active fire is lost.
Wood-burning stoves or solid fuel ranges, however, are an increasingly popular alternative to open fires, as they provide a more efficient way of generating a cosy atmosphere. According to the 2022 census, while just over 30,000 households reported using wood fuel as their primary heating source, 245,000 households indicated that they burned wood as a supplementary heating source, and 450,000 homes have a stove or range for burning solid fuel.
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Modern wood-burning stoves must satisfy EU regulations known as “Ecodesign”, which puts limits on gaseous emissions permissible from the stove, and requires the fuel that is burned, whether wood or coal, to also satisfy specific requirements to limit moisture. However, these standards are regarded as relatively weak and will be revisited in 2026 by the European Commission.
Wood-burning stoves generate both indoor and outdoor air pollution. They release significant quantities of tiny particulates that cause health and respiratory problems and exacerbate conditions like childhood asthma.
The smoke is composed of the same harmful pollutants (particles and PAHs) as tobacco smoke, which increases risk of cancer, blood clots, cardiovascular diseases, asthma, bronchitis, COPD and other illnesses. Up to 55 per cent of fine particulate matter emitted from newer logwood stoves consists of black carbon, which is as toxic as the black carbon emitted from diesel cars.
According to the organisation Green Transition Denmark, citing data from Aarhus University, just 17,000 wood stoves across Copenhagen during winter “emit twice as many fine particles” than the city’s all road traffic for a whole year.
Non-governmental organisations working on the new EU Ecodesign regulations argue there is significant potential to reduce emissions by applying best available technologies such as precipitators (filters), automated combustion controls and catalytic converters to reduce pollution from wood-burning stoves. However, raising the standard for Ecodesign will likely increase the cost of burning wood and solid fuel.
While wood is indeed a renewable fuel, it is not carbon neutral. Carbon dioxide emitted from burning wood stays in the atmosphere, trapping heat just as long as that emitted by coal and oil. Burning wood releases a large pulse of climate pollution immediately, and it can take decades or even centuries for replanted trees to reabsorb that same amount of carbon.
Moreover, there is a finite amount of sustainably harvested woody biomass available to use as a fuel, and a minimal amount of Irish sustainably grown and harvested, kiln-dried timber (though there are also Irish wood briquettes manufactured from compressed wood waste).
All distributors of timber sold in the State are required to be registered with the Environmental Protection Agency and comply with air pollution regulations. Yet the wood quality certification standards are voluntary, and enforcement by local authorities of environmental regulations is patchy.
The public is understandably confused by advertising campaigns which portray wood-burning stoves as better for the environment. Earlier this month, the UK advertising standards authority banned two commercials claiming that choosing a modern stove and dry wood fuel can significantly lower emissions, after finding them “misleading and unsubstantiated”.
Ultimately, resilience in the middle of a climate crisis cannot depend on burning stuff, except as a very last resort and using timber harvested sustainably in stoves that are not damaging human health.
Biomass will likely play a minor role in home heating scenarios across Europe, so it would be foolish to design policies that assume Irish homes will have wood-burning stoves.
Ecodesign standards should be improved, but this means that stoves are likely to become more expensive as their actual social and environmental impacts are reflected in the price. For cities, district heating and heat pumps are still the best solution by far.
- Sadhbh O’Neill is an independent climate and environmental researcher, and Irish representative on the Council of the European Environmental Bureau
