Are log burners bad for the environment?

The Eco Experts

Log burners produce 465 times more toxic air pollution than gas boilers

They’ve been banned from new and refurbished homes in London

More Brits support a ban on log burners than oppose it


Log burners, also known as wood-burning stoves, seem like they should be sustainable – but they’re not.

They produce extremely high levels of toxic air pollution, and reduce the number of CO2-reducing trees in the world.

The CO2-absorbing powers of these trees can’t be replaced for at least 10 years, and often not for 40 years.

In this guide, we’ll explain how and why they’re bad for the environment, as well as your potential next steps.

log burner in the middle of a room in a house

Are log burners bad for the environment?

Log burners are extremely bad for the environment.

They’re the worst way to heat your home in terms of pollution, unless you’re planning to burn solid coal or light an open fire.

These machines are fuelled with mature trees that absorb large amounts of CO2 – until they’re felled and thrown into a fire that releases all that CO2 in one go, along with other harmful pollutants.

Even if you plant more trees, they won’t reach maturity for at least 10 years, and usually 40 or more – and until they do, they’ll barely absorb any CO2 from the atmosphere.

Why are log burners bad for the environment?

Log burners are bad for the environment because they reduce the number of mature trees in the world, emit tremendous amounts of CO2 and PM2.5*, and do all of this with the lowest average efficiency rating of any domestic heating system.

Let’s go through each of these factors one by one.

 

* PM2.5 is particulate matter that’s smaller than 2.5 microns

Carbon emissions

Log burners are bad for the environment because they take trees – a resource that reduces an area’s carbon footprint – and turn them into massive emitters of CO2 and PM2.5.

The average household with a log burner requires 1.25 tonnes of wood per year – which means cutting down trees that would otherwise have continued cutting the absorbing 50 kg of CO2 per year.

When these trees are burned, all the CO2 they’ve taken in during their lifetimes is released.

This means the average three-bedroom household with a log burner ends up releasing 5.36 tonnes of CO2 per year – more than twice as much as a gas boiler.

PM2.5 emissions

Log burners are also responsible for 17% of the UK’s emissions of PM2.5.

These small, inhalable particles negatively affect the wellbeing of humans, animals, plants, and ecosystems – and they speed up climate change.

The Department for Environment Food & Rural Affairs has said that “exposure to PM can result in serious impacts to health, especially in vulnerable groups of people such as the young, elderly, and those with respiratory problems.”

Low efficiency

To make things even worse, log burners come with relatively low efficiency ratings.

New models must legally be at least 75%, but this is considerably lower than gas boilers – which hover around 95%, on average – and heat pumps, which usually come with at least 300% efficiency.

This means that for every unit of wood thrown into a log burner, 0.75 units of heat comes out – which is clearly a bad rate.

home chimney emitting dark smoke

How bad are log burners for the environment?

Log burners are very bad for the environment.

They’re more than twice as bad as gas boilers in terms of CO2 emissions, and they release enormous amounts of PM2.5, which can enter people’s blood and lungs.

Log burners manage to emit more PM2.5 pollution than all road traffic in the UK, despite only 8% of homes having one.

The government’s Chief Medical Officer Sir Chris Whitty has found that the most modern type of log burners emit 465 times more toxic air pollution than gas boilers.

In his annual report, he concluded that “in urban areas, burning wood has the potential to worsen local air quality significantly.”

Log burners have such a negative impact on an area’s air that in February 2023, the Mayor of London effectively banned them in new and refurbished buildings across the capital.

As well as affecting people’s health, log burners also speed up climate change and exacerbate the UK’s problem with residential carbon emissions, which is the only major category that hasn’t seen a reduction since 2014 – in fact, it’s risen.

Can you make them more environmentally friendly?

If you’re looking to reduce your impact on the climate, you can take steps to make log burners as environmentally friendly as possible, simply by ensuring your wood stays dry.

It’s now illegal to burn wet wood, which adds an extra motivation.

Firstly, make sure you only purchase wood that comes with a ‘Ready to Burn’ label. This indicates it contains less than 20% moisture, which will reduce your emissions.

It’s now illegal to sell wood for domestic use that’s wetter than this, but keep an eye out anyway.

Once you’ve bought your wood, keep it as dry as possible, either by storing it inside or elevated above the ground and protected from the elements if it’s outside. Stacking your logs instead of tossing them into a pile will also ensure they stay dry for longer.

When you’re ready to burn a new pile of wood, bring it inside at least 24 hours before you plan to use it.

However, the best step you can take for the environment is to replace your log burner with a more eco-friendly machine – like one of the best air source heat pumps on the market.

How does a log burner compare?

Average three-bedroom house (tonnes)

Log burner

Oil boiler

Gas boiler

Biomass

Infrared

Heat pump

Annual CO2 emissions

5.36

3.47

2.55

1.21

2.09

0.7

Annual toxic air pollution

4.02

0.009

0.07

2.59

0

0

Log burners are the most polluting form of domestic heating.

They release twice as much CO2 as gas boilers and 465 times more toxic air pollution – like PM2.5.

As if that wasn’t bad enough, they also require the chopping down of trees, which otherwise have an actively positive effect on the climate – unlike gas or oil, for instance.

Are log burners going to be banned?

There are no plans to ban log burners in the UK.

However, new regulations were brought into effect in 2022 that require all newly manufactured log burners to meet the European Union’s Ecodesign standards.

This includes a requirement for log burners to have an efficiency rate of at least 75% – which still makes them the least efficient way of heating your home, by far.

If you still have a log burner or you’re thinking of buying a new one, you won’t be breaking the law by continuing along that path, but that doesn’t mean it’s a good idea – and Brits agree.

44% of people in Britain support a log burner ban, with 36% opposed, according to a poll by The Guardian.

Can you get an eco-friendly log burner?

There’s no such thing as an eco-friendly log burner.

Some log burners are more eco-friendly than others, however: models with an efficiency rate over 75% are much better for the environment than older versions that were 60% efficient or less.

But every log burner emits CO2 and PM2.5 at a dangerous rate, which is why they’ve been banned from new and refurbished buildings in London.

Only coal fires and open fires are worse for the environment – and log burners will soon join these heating methods on the scrapheap of history.

The future doesn’t contain eco-friendly log burners, because it doesn’t contain log burners at all.

Should I get rid of my log burner?

You should get rid of your log burner if you want to drastically reduce your carbon footprint and the amount of unhealthy pollution your heating system produces.

After all, log burners release 465 times as much toxic pollution as gas boilers.

Much of this is PM2.5, which has been connected to health issues from heart and lung conditions to dementia and depression.

In total, air pollution causes 26,000 and 38,000 per year in England – so any action you take to reduce this figure is worth it.

You may want to consider an air source heat pump, which doesn’t release any toxic pollution and is only responsible for as much CO2 as the National Grid’s electricity emits.

Depending on your property’s energy efficiency and your financial position, you may be able to access some government grants to help you afford a new heating method.

Summary

Log burners are terrible for the environment.

This is despite new models meeting Ecodesign standards, which have at least resulted in machines that release eight times less toxic air pollution than they did previously.

This pollution affects every organ of the body, and has no place in modern society – especially since much cleaner heating methods are readily available.

FAQs

Log burners absolutely contribute to global warming.

They release twice as much CO2 as gas boilers, which increases when households burn wet wood.

Log burners also emit 465 as much PM2.5 as gas heating, which exacerbates global warming too, as well as causing multiple health problems for people in the surrounding areas.

The biggest negatives of a log burner are that it’s bad for your air quality, it massively contributes to climate change, and it requires you to carefully maintain your wood supply.

The toxic air pollution that a log burner emits is bad for your health and the planet’s health – and it produces 465 times more of it than a gas boiler does.

Wood burners aren’t worse than open fires when it comes to air pollution.

Older wood burner models were almost as bad as open fires, but modern wood burners must meet the European Union’s Ecodesign standards.

This means new wood burners release eight times less toxic particles than old models – but they still emit 465 times more than gas boilers.

Written by:
josh jackman
Josh has written about eco-friendly home improvements and climate change for the past four years. His work has been displayed on the front page of the Financial Times, he's been interviewed by BBC One's Rip-Off Britain, and he regularly features in The Telegraph and on BBC Radio.
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