Carbon Footprint of Wood Burning Stoves: The Real Answer (With Graphics)

Man kneeling next to a wood burning stove sees a carbon emissions footprint from the wood burning stove and wonders what is the carbon footprint of wood burning stoves and are wood-burning stoves environmentally friendly?

The carbon footprint of wood-burning stoves isn’t a question that many people wonder about, but the U.S. Environmental Protection Agency has advocated for cleaner fireplace units for a long time.

Since it is common for many households to have a wood-burning fireplace as a heat source in the cold months (or in the event of a power outages) and for aesthetics, knowing how many emissions it can create can be helpful for reducing them.

Although one of the most primitive and reliable sources of heat, a wood burning stove in a household is practical, and the EPA has provided enhanced alternatives for the high carbon emission stoves than many U.S. residents currently use.

But, understanding the real answer to the carbon footprint of wood burning stoves is a little tricky to figure, because there are indirect emissions as well as the direct emissions produced by burning wood.

This complete guide explains how to measure it and how to reduce wood stove emissions.

CO2 Emissions By Fuel Type, Wood, And Other Fuel Types

Different fuel types produce different levels of carbon emissions.

Since wood actually stores carbon absorbed from the atmosphere, when it’s burned, the process releases much of the carbon emissions back into the air.

The sequestered carbon in wood is released back into the atmosphere during combustion. On average, the weight of the wood time 1.5 is the amount of carbon emissions released. However, a number of factors impact that amount, including the type of wood, how much of it’s moisture has been released (how dry it is) and other factors.

The following table outlines the measurements for various types of fuel used for heating.

FuelCarbon ContentNet CVTotal CO2 Emissions (Annually)  To Heat a Typical House – 20 MWh p.a.Approximate Life Cycle CO2 Emissions
%MJ/kgkgkg saved c.f. gaskg saved c.f. oilkg/MWhkg/GJ
Natural gas75384,04001,16020256
Electricity3,8601801,34019354
Oil85425,200-1,160026072
Hard coal75297,260-3,220-2,060363101
LPG582465,600-56060023072
Electricity: large-scale woodchip combustion1,1603,3805,1205816
Electricity: large-scale woodchip gasification5004,0405,780257
Woodchips: 25 percent MC, fuel only37.5141404,4006,14072
Woodchips: 25 percent MC, inc. boiler37.5143604,1805,920185
Wood pellets: 10 percent MC drying from green wood using gas45171,6002,9404,6808022
Wood pellets: 10 percent MC starting from dry wood waste45173004,2405,980154
Wood pellets: 10 percent MC drying from green wood using gas, inc. boiler45171,8202,7204,4609125
Grass/straw: 15 percent MC3814.5108 to 3004,240 to 4,4325,920 to 6,1725.4 to 151.5 to 4
Wood pellets: 10% MC, inc. boiler45175204,0205,760267

CO2 Emissions Per kWh By Fuel Type Analysis Chart

With using the kilowatt hour of primary energy and the megajoules per gram of primary energy (MJPE), fuel type emissions can be compared.

FuelEmissions in g CO2/kWhPEEmissions in g CO2/MJPE
Wood367.6102.1
Lignite398.7110.8
Hard Coal338.293.9
Gasoline263.73.3
Fuel Oil266.574.0
Diesel266.574.0
Crude Oil263.973.3
Kerosene263.973.3
Liquid Petroleum Gas238.866.3
Natural Gas200.855.8

Graph that shows CO2 emissions per Kwh by Fuel type.

How Does Burning Wood Affect the Environment?

There is a debate as to whether burning wood for energy is good for the environment. While trees are renewable and therefore easily classified as a renewable energy source, burning them produces carbon harmful to the environment.

Some people argue that wood burning should be considered carbon neutral because the CO2 emitted in the process can be utilized by plants for photosynthesis. Also, because trees can be used to sequester carbon emissions, the CO2 from wood-burning can be erased using a one month carbon offset.

Pieces of wood burning.

(Image: Daiga Ellaby11)

However, some reasons complicate the whole process and rule out the straightforward classification of wood burning as carbon neutral. Those reasons include;

Trees Emit More CO2 Than Fossil Fuels

When you compare the amount of CO2 emitted per unit of energy for different fuel types, you realize that wood burning is at the top of the list.

It is 2.5 times higher than natural gas and about 30% more than coal.

Harvesting Trees for Energy Interferes With Carbon Sequestering

Trees are a major contribution to global carbon offset initiatives. The trees can store a lot of carbon by sucking it from the atmosphere and into the soil.

However, that is only applicable when the tree is still growing. If you harvest the tree for energy, it means that all the carbon the tree was holding will be released back into the environment. Also, there is no chance of further carbon sequestering once you cut down the tree.

Re-Sequestration of the Released Carbon Is Not Instant

Once you burn trees for energy and produce carbon from the process, it will take a long time to be reabsorbed back into the soil through sequestering. That is not good for the environment as the more it stays in the air, the more damage it will cause.

Burning Wood vs Coal Emissions

Burning wood is often marketed as clean and renewable energy, which does not have bad environmental implications. However, wood burning produces way more carbon than coal. Drax, the world’s largest wood burner for energy, has way more climatic implications than coal plants.

Compared to other electricity production fuel types, it ranks second after fossil fuels6 in emissions. 1 Due to the low energy density of wood, it has to be burned in higher volumes to produce biomass and generate electricity. That is way lower than the amount of coal needed for the same amount of energy.

Closeup of wood burning.

(Image: Katie Moum12)

For that reason, wood burning emits more CO2 per kWh of electricity than coal. When you compare large-scale wood burning to all the coal burning, even in steel production, the wood emits more CO2 into the air.

The biomass industry markets wood-burning for energy as carbon-neutral, but it is not as straightforward as they make it sound. The real answer to whether wood burning has environmental implications is yes. Drax is among the number top CO2 emitters in the electricity production sector. Also, large-scale wood-burning plants emit more CO2 than coal plants.

The Truth About Wood-Burning Stoves: The Carbon Footprint of Wood-Burning Stoves

Most people prefer wood-burning stoves for heat and energy because of their many benefits. One of them is that wood is readily available and is, therefore, a renewable energy source.

It is also an affordable heat source because you can find pieces of wood to burn for free. Regarding environmental implications, the carbon footprint of wood-burning stoves is a point of debate between manufacturers and scientists.

While wood is inexpensive, renewable, and comes from trees that can be used to sequester the carbon produced after burning, wood burning is not carbon-neutral. It has major effects on the environment when done on a large scale. Also, the non-EPA-approved wood-burning stoves also produce harmful gases that could lead to future effects on climate change.

Therefore, wood-burning stoves can only pass the environmental protection test if manufactured to the EPA-required standards. Traditional wood-burning stoves are as harmful to the environment as any other pollutant.

Wood Stove Particulate Emissions: Are Wood-Burning Stoves Environmentally Friendly?

Wood burning produces more particle pollution than road transport. While road transport stands at 13% of pollution, wood burning is at 17%.7

A single wood-burning stove might not have severe environmental implications. Still, when you combine the emissions from every home with a wood-burning stove over a year, there is a lot of environmental damage.

Graph that shows particulate emissions of wood stove and other sources.

Below is a table that compares the particle pollution of wood stoves and other pollutants.

Carbon Footprint of Wood-Burning Stoves: Wood Stove Emissions Comparison Table

SourceEmissions (Grams/hour or day)
Pellet Stove2.4g/hour ( 56.6 g/day)
Gas/Propane Furnace.001g/hour ( 0.024 g/day)
Cigarette.4 grams/hour (0.8 g/pack)
Oil furnace.02g/hour (0.48 g/day)
Certified Wood Stove8.2g/hour (196.8 g/day)
Single Simulated Log8 g/hour
Fireplace – hardwood  (36 lbs. or 16 kilograms burned over 3 hrs.)30 g/hour
Non-certified wood stove15.6 g/hour
Auto (without Catalytic Converter)3.5 g/hour.
Fireplace-softwood (31 lbs. or 14 kilograms burned over 3 hrs.)59 g/hour.
Diesel 14-ton Truck or Bus >199436 g/hour
Auto (with Catalytic Converter).66 g/hour
Diesel Truck or Bus < 199370 g/hour
Auto – smoking6 g/hour

Carbon Footprint of a Campfire

Burning wood releases a lot of volatile organic compounds like CO2, carbon monoxide, benzene, and nitrogen oxides.

All these compounds are bad for the environment and therefore make campfires an environmental hazard.

Photo of a burning charcoal for a campfire.

(Image: Wren Meinberg13)

The weight of the wood will help you determine the CO2 emissions. Wood is cellulose and is about 33% carbon in weight. When the carbon is converted to CO2, the emissions will be more than the weight of the wood.2

For example, if you have wood weighing 10 kg, 20% is water, and eighty percent cellulose, which makes up 33 percent carbon (2.64 kg). Once you convert it to CO2, it will be about 9.68 kg, almost the wood’s weight.

Implications of Burning Rotten Wood Outside

Burning rotten wood can make you sick, especially if you have allergies or asthma.

The same way you should not burn painted, treated, or glued wood is the same way you should not burn rotten wood. It produces a pungent smell and can release mildew, mold, and fungus.3

Close-up photo of a burning wood.

(Image: Obed Hernández14)

If you inhale that bacteria, you could experience respiratory tract problems. It could also give you a headache or stuffy nose. The rotten wood material also carries many insects, which could end up in your home if you burn the wood in your chimney. Also, rotten wood does not burn effectively, so it won’t be as effective as you want.

Carbon Footprint of Wood-Burning Stoves: How To Reduce Pollution From Wood-Burning Stoves

Wood-burning stoves are an essential part of most homes. They also come in handy because of the reduced costs and ease of use. However, they could also be causing a lot of air pollution that harms you and the environment. Below are tips to help you reduce the carbon footprint of wood-burning stoves.

Burn Dry Wood

A moisture level of twenty percent or less is the best for wood that you use in a stove.8 You can buy a moisture meter for that or wood with a ready To Burn logo on it. Alternatively, you can dry the wood before using it on your stove or ask the supplier whether they have pre-dried it.

The drier the wood, the less energy and time it will take to remove any moisture. Therefore, the wood will burn fast enough, and there will be fewer particle emissions. Ensure you check the dryness of your logs before using them on your stove.

Burn With a Flame

The best way to use your stove and ensure there are the least emissions from it is to burn it with a visible flame. Burning it at a lower output will only increase the emissions and will not increase fuel efficiency.

Use Smokeless Fuel

There are types of coal that emit very few smoke particles as they burn. That is the best fuel for your stove, especially if it can use multiple fuel types. It will help reduce the environmental implications of burning these other fuel types.

Keep Your Stove Clean

A well-maintained stove is safe to use and ensures that it lasts as long as it should. Cleaning your stove and the chimney removes all the buildup left after the wood burns, which is good for you and your home. You should also keep the stove as dry as possible to avoid wetting the wood and making it hard to burn.

Use Efficient Fuel

Different tree species have different levels of efficiency when used as firewood. For example, hardwoods take longer to burn because of the density of the wood. The best woods to use as firewood are those that will burn fast and reduce the time they keep burning.

That will, in turn, reduce the number of emissions into the atmosphere. Some of the best trees to use for firewood are Apple,  Hawthorn, Ash, Birch, Horse Chesnut, Beech, Oak, Thorn, and Robinia.

Environmentally Friendly Alternative to Wood-Burning Stove: Wood Fire Alternatives

Wood-burning stoves have a high carbon footprint that could cause climate change in years to come. You should use better alternatives for the environment to keep you and the entire ecological system safe from harmful emissions. Below are the best alternatives for wood-burning stoves today.4

  • Gas fire
  • Bioethanol fire
  • Electric fire

Good Alternative Fuel for Wood-Burning Stoves

  • Wood Wax Firelogs
  • Coal
  • Oil
  • Corn
  • Wood Pellets

Wood-burning stoves are slowly being replaced by other energy-efficient and safer stoves. That is because of the carbon dioxide released when the wood is burned. Even though most people say that wood burning is carbon neutral, it has a huge impact on the environment.

The large scale wood-burning plants like Drax cause the most damage, but even individual wood stoves at home can contribute to the overall damage. To reduce this, burning energy-efficient fuels in your stove can limit the carbon footprint of wood-burning stoves.

Frequently Asked Questions About Carbon Footprint of Wood-Burning Stoves

Can Burning Rotten Wood Make You Sick?

Yes. Inhaling the bacteria from the wood is bad for your respiratory tract. It also has a very bad smell that could cause headaches or a stuffy nose. If you have asthma or any allergies, burning rotten wood might trigger them.

Can You Burn Rotten Wood in Fire Pit?

The wood may burn and smoulder, but it releases harmful toxins to the surrounding area.

Can You Burn Rotten Wood Outside?

Burning rotten wood anywhere is generally bad for your health and the environment.

How Much CO2 Does a Gas Fireplace Produce?

Each cubic foot of gas that is burned in a fireplace releases about 1 cubic foot of CO2.

How Much Does Burning Wood Contribute to Global Warming?

Burning wood produces CO2 and other harmful gases that could cause global warming.9

Why Is Wood More Sustainable Than Natural Gas as a Fuel for Central Heating Boilers?

Because wood comes from trees, you can plant as many trees as possible to produce wood for burning. Natural gas can not be recreated in the same way.

Why Is Wood Not a Fossil Fuel?

Wood is not a fossil fuel because it is not used in it’s fossilized form to generate heat or energy.

How Much CO2 Does a Wood Fire Produce? (How Much CO2 Does a Fireplace Produce?)

That depends on the weight of the wood and how long it takes to burn.

Is Wood a Fossil Fuel or Biofuel?

Wood is a biofuel. That is because it is a renewable energy source.

Is Burning Brush Bad for the Environment?

Yes. Burning brush releases harmful gases into the atmosphere and could affect the higher levels over time.10

Are Wood-Burning Stoves Bad for the Environment?

In many cases, a wood burning stove isn’t the best heat producer for the environment, but it can be more efficient in remote locations.

Are Gas Fireplaces Bad for the Environment?

Natural gas, a fossil fuel, indirectly impacts the environment because it is excavated from the earth.

Is It Better To Burn Wood or Let It Rot?

Letting it rot will produce methane, but that will happen over a long period of time. However, methane is a much more dangerous greenhouse gas than carbon emissions, which can be sequestered by planting more trees.

Does Rotting Wood Release CO2?

Yes, it does.

Do Electric Alternatives to Wood-Burning Stoves Help Reduce Carbon Emissions?

Electric alternatives to wood burning stoves do generate somewhat less emissions, but the production of the stove and the generation of electricity also produces emissions.

Which Is the Most Environmentally Friendly Wood-Burning Stove?

The wood pellet stove.

Read More About Carbon Footprint of Wood-Burning Stoves


References

1Harrison, T., & MacDonald, P. (2021, October 8). UK biomass emits more CO2 than coal. Ember | Coal to clean energy policy. Retrieved December 10, 2022, from <https://ember-climate.org/insights/research/uk-biomass-emits-more-co2-than-coal/>

2Reddit. (2022). How much carbon dioxide does a standard campfire emit? : r/askscience. Reddit. Retrieved December 10, 2022, from <https://www.reddit.com/r/askscience/comments/h5tuq/how_much_carbon_dioxide_does_a_standard_campfire/>

3Firewood For Life.(2022). Rotten Firewood – Should You Burn It?. Firewood For Life. Retrieved December 10, 2022, from <https://www.firewood-for-life.com/rotten-firewood.html>

4Federation of Master Builders. (2021, November 18). Wood burning stove alternatives. Federation of Master Builders. Retrieved December 10, 2022, from <https://www.fmb.org.uk/resource/wood-burning-stove-alternatives.html>

5University of Wisconsin-Stevens Point. (2020). Facts about Propane. University of Wisconsin-Stevens Point. Retrieved December 20, 2022, from <https://www3.uwsp.edu/cnr-ap/KEEP/Documents/Activities/Energy%20Fact%20Sheets/FactsAboutPropane.pdf>

6The National Academy of Sciences. (2022). Fossil Fuels – Our Energy Sources. The National Academies of Science, Engineering, Medicine. Retrieved December 20, 2022, from <http://needtoknow.nas.edu/energy/energy-sources/fossil-fuels/>

7US EPA. (2022, July 7). Particulate Matter (PM) Pollution. EPA. Retrieved December 20, 2022, from <https://www.epa.gov/pm-pollution>

8University of Maryland Extension. (2018, November). Measuring Wood Moisture & Drying Time for Hardwood Tree Species. University of Maryland Extension. Retrieved December 20, 2022, from <https://extension.umd.edu/sites/extension.umd.edu/files/publications/MeasuringWoodMoisture_FS-1074.pdf>

9Global Climate Change: Vital Signs of the Planet. (2022). Global Warming vs. Climate Change. NASA Climate Change. Retrieved December 20, 2022, from <https://climate.nasa.gov/global-warming-vs-climate-change/>

10Department of Environment, Great Lakes, and Energy. (2022). Trees and Brush. State of Michigan. Retrieved December 20, 2022, from <https://www.michigan.gov/egle/about/organization/water-resources/dam-safety/trees-and-brush>

11Daiga Ellaby. Unsplash. Retrieved from <https://unsplash.com/photos/hUFcg942g0U>

12Katie Moum. Unsplash. Retrieved from <https://unsplash.com/photos/qN6JwTCakmI>

13Wren Meinberg. Unsplash. Retrieved from <https://unsplash.com/photos/xqV9QdGOSas>

14Obed Hernández. Unsplash. Retrieved from <https://unsplash.com/photos/Pdcqx39Zazg>