When trees are taken, what is lost from the forest?

Hi, Nice site. I recently bought a house whose source of heat is a wood burning stove. I've really gotten to enjoy using it and I was very interested in your environmental reasoning for using wood vs. fossil fuels.

I looked all over your site and read the All About Smoke section, but have not been able to find an answer to this question:  What is the chemical constituency of wood? I understand that there is carbon, oxygen and hydrogen, but what I am looking for is all the materials that make up wood so I can differentiate which substances are burned off (smoke) and which ones stay in the fireplace (ash). I am very curious for reasons of sustainability. When wood is taken from a forest, a certain amount of minerals are taken with it. As a tree grows it stores carbon from the atmosphere, but also "pulls" minerals/substances/chemicals from the soil that also are stored in the wood. When one takes a tree away from its native habitat, one is also taking these substances away. The carbon will get cycled back into the atmosphere, but the other substances have been removed permanently. I would like to know what all those substances are, both the ones in the ash, and the ones that may also go up the chimney with the smoke.

Thanks, Mike

Hi Mike,

Yes, you are quite right that when trees are taken for fuelwood something is lost from the site.  You are also right that the main loss is in the form of minerals. However, keep in mind that in the entire life cycle of the tree, the part taken is only certain fraction of the total contribution to the site of that tree. Each year deciduous trees deposit a fair mass of leaves on the forest floor and coniferous trees drop leaves on a continuous or multi-year cycle. Over a 50 year period that is a big contribution to the mineral and biomass stock of the soils. When it is harvested, we take only the bulky solid wood, not the entire tree. Also, in most of North America about half (it is hard to estimate) of the firewood produced is a byproduct of other forestry operations that produce saw logs or pulp.

As we point out up front, whatever energy source you use will have impacts.  I can only say that I've seen wood lots that have been harvested selectively for firewood for generations and they look terrific. My assessment is that a healthy, well managed forest can tolerate a moderate loss of biomass each year without any decline in viability.

To get a more scientific answer you would have to ask a forest ecologist, of which there are very few.


Wood burning is bad for your health?

I went to one of the links and there was a whole nine pages of why woodstoves are bad for you and the environment. In particular, it talked about the toxins and carcinogens that wood burning lets off.  It seems we have to decide to either burn a hole in our lungs or burn a hole in our pockets.???

Tracy in Toronto

Hi Tracy,

We link to Burning Issues as much for comic relief as for factual commentary. Pick any single environmental issue and you'll find at least one organization run by fanatics. Burning Issues is run by folks who are, for whatever reason, fanatical about wood smoke. From our point of view, it is better to have opponents who are so intemperate, so radical, so uncompromising as to be dismissed by reasonable people as fringe loonies. That's why we are happy to link to Burning Issues.

Please don't misunderstand me, we don't consider wood smoke good to breathe. Clearly, it is not healthy for you.  But neither is diesel truck and bus exhaust or car exhaust or many other pollutants.  This is from the Union of Concerned Scientists:

"The average truck on the road today spews 22 grams of smog-forming pollution and nearly one gram of soot every mile."  See:

That is about 60 g/h of particulate matter at highway speed. My EPA certified wood stove emits an average of 3 g/h of particulate matter per hour of operation. So what should have priority, my home heating or a truck taking computer games to Wal-Mart?

I don't like to justify wood burning emissions just by saying the other guy is worse, but we must put all pollution into proper perspective and reduce it all.  At woodheat.org, we don't suggest that everyone in Toronto should start heating with wood, quite the opposite.  We think wood is appropriate as a regionally specific energy resource.

So, I don't think the options are "to either burn a whole in our lungs or burn a whole in our pockets".  Responsible people can reduce their personal pollution and also reduce cost by choosing good equipment and practicing energy conservation.  The fact is we'll all be practicing energy conservation fairly soon whether we like it or not.  See:


Finally, in light of Burning Issues warnings of immanent disease and death from wood smoke, consider this: The human species lived with its collective head in a cloud of wood smoke for its entire million year history on earth, until the last 150 years.  If the periodic exposure to the smell of wood smoke were anything like as toxic and dangerous as the fanatics would like you to believe, we never would have got this far.


Misleading Statement?

In searching for material  on wood burning stoves, I  came across your web site. I find that it has a good  deal of useful information,  however, there is a very misleading statement that  is made on the homepage.  It is given below.

"But when it is used  effectively, wood is a  fine fuel compared to the  fossil fuels like oil, gas  and coal, whose consumption  leads to global warming."

I will not get into the debate  of does carbon dioxide cause  global warming, because I think  the answer is not really known. However, to make the assertion that burning wood is better than burning oil, gas, or coal because  of global warming is absurd. Wood  like these other fuels is a  hydro-carbon. If it is burned  completely and perfectly, its byproducts, water and carbon  dioxide, are the same as what is  produced from burning coal, oil,  or gas.   The statement on your home page  should be modified to reflect  the facts. It will also lend credibility to your site.


Hi John,

We find your message very interesting, not least because we gather you are with Sandia Labs.  You are not just a curious nonspecialist who might be unfamiliar with the carbon cycle as it relates to atmospheric CO2 and biomass growth, decay and combustion. See:



(or simply type 'carbon cycle' into any search engine)

We don't spend time debating the greenhouse gas/global warming/climate change issue because more than sufficient information is available now to take action.  We note that those who persist in denying any connection are usually paid to do so, directly or indirectly, and therefore lack credibility.

We stand by the quoted statement on our site – it is not misleading.  We think it is misleading to suggest that, in the area of energy use and the environment, business as usual is the desirable strategy.  You are just going to have to live with the fact that we disagree with you.




A challenge to wood as a renewable resource

While I agree that wood heat alternatives might be better in the short term than fossil fuel dependency, the world is also in deforestation crises, and by encouraging wood use, you are fostering this depletion – another imbalance to our ecology.  We need to find an alternative energy source that truly is "alternative" and does not rely on "endangered" resources.

Sincerely, Roberta


Only a fool would suggest that wood is the right fuel for all regions and all situations (as the fossil fuel promoters do for oil and gas). You can dismiss us as irresponsible if you wish, but I think we promote the moderate, sustainable use of wood as a fuel.  I am guessing that you don't fully understand the concept of renewability (see this page).

It is naive to think that 'science' will surprise us with a new energy source that will solve all our problems. The solution lies in using a lot less energy of all types and using more regionally specific and appropriate fuels. But then, I suspect you have your mind made up.


Roberta responds:


Thank you for responding so promptly and so intelligently! Your "suspicion" is correct in that I haven't fully explored your concept of renewable as far as wood burning is concerned – and yes, I agree, it's naive for us to think that "science" will save us and our Mother Earth. I'm just recently reading Thom Hartmann's book, "The Last Days of Ancient Sun" and am blown away by how serious our situation is – and am deeply concerned as to how we can "wake people up" to become more responsible and change the "burn and conquer" mentality and history we've inherited. When I was "surfing the net" and marking sites for future reading, yours just happened to have an email response for me to complain to. No, I haven't gotten my mind made up – I'm just concerned and exploring.

Again, thanks for your response – and good luck!