# Which is more polluting... A car or a wood stove?



## FyreBug (Jan 26, 2011)

And now for some slightly useless information. Someone has actually been able to do the hard data & calculations. Before we give the answer  i'd be nice to see in a poll what you think. Bonus points if you tell us by what margins. Not to get all scientific on you but its assuming we are comparing the same amount of energy expended. (pollution = CO2)

So go ahead, let us know what you think and the answer after the break...

Back from the break... First of all there were some mention as to CO2 is a pollutant or not. It depends on how you define a 'pollutant'. Just about anything can become toxic in high enough a concentration. Let us just say to assuage some sensibilities the terminology should have been "higher rate of CO2 emmission" although it's a mouthful. And please do not take this too seriously, this is just a fun exercise. There's too many variables but at least it provides a bit of a picture. All numbers are metric it's easier to calculate. So here we go...

1L of gas gives off 2.88kg CO2 after combustion.
Or volumetric mass of gasoline = 0.75
Where 750g of gas = 2.88kg of CO2 

in addition 1g of gas generate 13.35 Wh

Therfore 1lbl gas generate 6008W
But a 1lbl of wood generate 8500BTU = 2428W

It means that if it takes 15 Litres (4 US Gallons) of gas to travel 300 Kms (185 miles) it would take you  28.12kg (62 lbs) of wood to develop the same energy. 

15L of gasoline will emit : 43,2kg of CO2
28.12kg of wood : 4.22kg of CO2

Which means a car emits about 10 times more CO2! Yah baby, my Ferrari does 150 miles per face cord!


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## madrone (Jan 26, 2011)

just CO2?


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## FyreBug (Jan 26, 2011)

madrone said:
			
		

> just CO2?



Yup CO2. But it would be nice to do energy comparison, particulate etc...


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## bogydave (Jan 26, 2011)

I'll bite. But not sure it's apple to apples.

If I didn't burn wood, I'd be using nat. gas, fuel oil or elect.

If I ran my car in my house to keep it warm ;
we'd die if I didn't run a pipe out the garage door for the exhaust. (I'd weather seal around the pipe somehow)

 I say the car, it is not near as efficient to heat my house as my wood stove. Not sure it would keep me above freezing, may have to sleep in the car to stay warm.

I think, even my oven would do a better job heating my house than a car.

so I voted "car fer sure" I'd need about 20+ of them with the heater blaring to heat the house.
Then the energy to build a bigger garage, & heat it, maybe even more.


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## daveswoodhauler (Jan 26, 2011)

Too many variables....what kind of car/exhaust/fuel??..what type of wood/moisture content etc...?
Only being on my third year with burning wood, I am pleased to say that on my way to work I see at least 10-15 chimneys that loo bad...lots of white smoke and some gray......mine only smokes when on reload for about 5 minutes.
My vore would be the car gives off more, that is when you are burning 20% less in an EPA stove


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## KevinACrider (Jan 26, 2011)

There's no way to compare apples to apples. The same car will perform differently in different areas. Not to mention different models of the same car wouldn't have the same results. On the contrary, the same stove will perform differently in different households with different wood, etc.


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## ControlFreak (Jan 26, 2011)

FyreBug said:
			
		

> And now for some slightly useless information. Someone has actually been able to do the hard data & calculations. Before we give the answer  i'd be nice to see in a poll what you think. Bonus points if you tell us by what margins. Not to get all scientific on you but its assuming we are comparing the same amount of energy expended. (pollution = CO2)
> 
> So go ahead, let us know what you think and the answer after the break...



CO2 is not a pollutant.


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## CarbonNeutral (Jan 26, 2011)

By what standard, per mile compared to per 1000 BTUs? I'm not getting in my stove to drive to the airport tomorrow, nor am I heating my house with my car.


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## Beetle-Kill (Jan 26, 2011)

Maybe not, but I DARE anyone of you to crawl under the covers with me after a big bowl of 5 bean chile, and swear you'd rather be there than sucking on an exhaust pipe! or shoving your face in a chimney for that matter. :sick:


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## phatfarmerbob (Jan 26, 2011)

cars for sure, burning wood is carbon nutral if you didnt burn the wood it would eventually die and release the stored carbon anyhow. a car is releasing carbon that would have been trapped underground presumably forever.... even an electric car would be more polluting unless it was charged with 75% or more "green energy"...seeing that some 50% of our power comes from coal and most the rest from oil.  anyhow theres my 2 cents someone correct me if im wrong, cause i could well be


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## Renovation (Jan 26, 2011)

Is the car burning?    Then definitely the car.


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## RedGuy (Jan 26, 2011)

ControlFreak said:
			
		

> FyreBug said:
> 
> 
> 
> ...



X2

As far as simply CO2 output I belive a stove would certainly put out more CO2. However as stated above the Co2 produced by a wood stove is offset by the oxygen the trees produced growing the fuel for the stove. As far as actuall pollutants a car definately produces more poluttants (other than CO2) than a wood stove.


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## colsmith (Jan 26, 2011)

As folks say, you can't drive anyplace in your stove, so what is the point of this comparison?  Anyway, I picked the stove as the answer, just because my car is a Honda Insight, a super ultra low emission and very light two seater car that gets 60 MPG in the summer and 45-50 in the winter.  My stove is supposedly quite efficient, and we are careful what we burn.  The other issue is you burn more often than you drive, at least most people, so pretty hard to compare.  But nevertheless, an interesting question.

P.S. I love Curious George, I mean the animated monkey, not the previous poster.


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## littlesmokey (Jan 26, 2011)

Ahhh, I'd hold off on not calling CO2 a pollutant, At least two US agencies are getting ready to call it a toxic gas :ahhh:  :-S  :coolgrin: 

But I can tell you this the stove and the car are nothing compared to a biometrically driven methane machine.... Five beans onions and a little extra Cajun salsa, and I can turn the air foggy.


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## Jutt77 (Jan 26, 2011)

FyreBug said:
			
		

> (pollution = CO2)



CO2 is now a pollutant...welcome to the new world of "green science" folks.  Anyways, the answer is dependent on too many variables as others have mentioned but I'll bite and say the answer is car.


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## bogydave (Jan 26, 2011)

Can I change my vote to methane?


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## remkel (Jan 26, 2011)

ControlFreak said:
			
		

> FyreBug said:
> 
> 
> 
> ...



I agree with you, but the EPA, MA DEP and others seem to think it is.....


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## remkel (Jan 26, 2011)

littlesmokey said:
			
		

> Ahhh, I'd hold off on not calling CO2 a pollutant, At least two US agencies are getting ready to call it a toxic gas :ahhh:  :-S  :coolgrin:
> 
> But I can tell you this the stove and the car are nothing compared to a biometrically driven methane machine.... Five beans onions and a little extra Cajun salsa, and I can turn the air foggy.



Just because two us agencies are going to call it a toxic gas does not mean they are right- there is a whole other agenda behind that designation.


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## Adios Pantalones (Jan 26, 2011)

The people saying that you don't drive a woodstove have the real right answer I think.  A straight per-year comparison would make more sense.  CO2 is arguably a pollutant, but there's far worse that comes out of a car or woodstove as far as health effects go so i don't care for that being the basis of comparison.


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## Pagey (Jan 26, 2011)

Six billion people exhaling CO2 every day.  Sounds far, far more polluting to me.  Better hope the world governments don't do the math on that one, or we might be facing some sort of population control.  Oh, wait...


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## DAKSY (Jan 26, 2011)

Pagey said:
			
		

> Six billion people exhaling CO2 every day.  Sounds far, far more polluting to me.  Better hope the world governments don't do the math on that one, or we might be facing some sort of population control.  Oh, wait...



Not only will they hafta regulate exhaling, they'll hafta regulate the amount of trees that die & rot in the forests, as well...


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## logger (Jan 26, 2011)

This is a no brainer since cars do not just appear in nature.  The most noticeable variable is the amount of energy, waste, and pollution involved in a car's making at the manufacturing plant.  Then take into consideration the energy and pollution caused to actually get rid of an old car even if parts have been stripped.   These two things alone cause more pollution than burning just wood, nevermind actually running the car during its driving lifetime.


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## FyreBug (Jan 26, 2011)

Back from the break... First of all there were some mention as to CO2 is a pollutant or not. It depends on how you define a 'pollutant'. Just about anything can become toxic in high enough a concentration. Let us just say to assuage some sensibilities the terminology should have been "higher rate of CO2 emmission" although it's a mouthful. And please do not take this too seriously, this is just a fun exercise. There's too many variables but at least it provides a bit of a picture. All numbers are metric it's easier to calculate. So here we go...

1L of gas gives off 2.88kg CO2 after combustion.
Or volumetric mass of gasoline = 0.75
Where 750g of gas = 2.88kg of CO2 

in addition 1g of gas generate 13.35 Wh

Therfore 1lbl gas generate 6008W
But a 1lbl of wood generate 8500BTU = 2428W

It means that if it takes 15 Litres (4 US Gallons) of gas to travel 300 Kms (185 miles) it would take you  28.12kg (62 lbs) of wood to develop the same energy. 

15L of gasoline will emit : 43,2kg of CO2
28.12kg of wood : 4.22kg of CO2

Which means a car emits about 10 times more CO2! Yah baby, my Ferrari does 150 miles per face cord!


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## logger (Jan 26, 2011)

FyreBug said:
			
		

> this is just a fun exercise.
> 
> 
> 1L of gas gives off 2.88kg CO2 after combustion.
> ...



Dude, Im not reading all that.  Nothing fun about math to me. lol.


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## zzr7ky (Jan 26, 2011)

I am familiar with real polutants which cause real problems, and have been regulated/managed for some time.

CO for example.  One can drive a modern car across the entire continental US and deliver less CO into the atmosphere than mowwing the lawn with a conventional lawn mowwer.   The CO levels are now low enough that running an exhaust line into and enclosed space (save a Ground Hog tunnel) will not harm the little darling.  Our automotive emissions regulations are very strong, but there are other sources that are not so well managed.

ATB, 
Mike P


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## FyreBug (Jan 26, 2011)

logger said:
			
		

> Dude, Im not reading all that.  Nothing fun about math to me. lol.



Well then... Just trust me!

BTW, i can provide the simplified version for $19.95 just PM me your visa #


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## Adios Pantalones (Jan 26, 2011)

Pagey said:
			
		

> Six billion people exhaling CO2 every day.  Sounds far, far more polluting to me.  Better hope the world governments don't do the math on that one, or we might be facing some sort of population control.  Oh, wait...



You breathe out about a kg of CO2 a day.  A car produces 8.8 kg of CO2 per gallon burned.


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## begreen (Jan 26, 2011)

Yep, that's 19.4 pounds! You can see why saving 10 or 20 mpg over 100,000 miles = a big number. At 25mpg, (4000gal) = 77,600 lbs CO2. At 40mpg (2500gal) = 48,500 lbs CO2. A 29,100 lbs difference. Multiply that difference times the ~255 million cars on just American roads and you get a 7,420,500,000,000 lbs reduction. Not a small number at all. And this does not include trucks which is another area where we can achieve fantastic differences with today's technology and by beefing up our rail networks to carry more freight. 

We can't stop people from breathing, but we certainly have the technology right now to make a very serious dent in our CO2 output. Doing so also reduces our dependence on foreign oil. It's a win-win situation.


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## BrowningBAR (Jan 26, 2011)

*Source: * *Emissions in Grams/hour or day*
Cigarette                                              *.4 grams/hour (0.8 grams/pack)*
Gas or Propane Furnace                    * .001 grams/hour ( 0.024 grams/day)*
Oil furnace                                          *.02 grams/hour (0.48 grams/day)*
 Pellet Stove                                      * 2.4 grams/hour ( 56.6 grams/day)*
 Single Simulated Log                            * 8 grams/hour*
 Certified Wood Stove                         * 8.2 grams/hour (196.8 grams/day)*
 Non-certified wood stove                    *15.6 grams/hour*
 Fireplace-hardwood:                             *30 grams/hour*
 (36 lbs. or 16 kg burned over 3 hours.)
 Fireplace-softwood:                              *59 grams/hour.*
 (31 lbs.or 14kg burned over 3 hours.)      
 Auto-with Catalytic Converter               *.66 grams/hour*
 Auto-without Catalytic Converter           *3.5 grams/hour*
 Auto-smoking                                         *6 grams/hour*
 Diesel 14 ton Truck or Bus >1994           *36 grams/hour*
 Diesel Truck or Bus < 1993                    *70 grams/hour*


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## begreen (Jan 26, 2011)

Very interesting graph. That would be fine particulate emissions, not CO2. Still it's an interesting comparison illustrating where we need to work first on air cleanup, fireplaces included. If they put ocean going boats on this chart, like some that call locally on the ports of Seattle and Tacoma, the particle emissions from bunker fuel would be way off of this chart.

PS: certified wood stove is listed at the top of the range. 2-4gms/hr is more typical.


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## Delta-T (Jan 26, 2011)

seems the way to go is to use condensed wood gas as a fuel for our cars....need to find something without fuel injection prolly for a retro fit.

and just because something is natural doesn't mean its not a pollutant. anything, well, most things, in excess can be dangerous.....even water.. hydro-toxicity.


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## BrowningBAR (Jan 26, 2011)

BeGreen said:
			
		

> Very interesting graph. That would be fine particulate emissions, not CO2. Still it's an interesting comparison illustrating where we need to work first on air cleanup, fireplaces included. If they put ocean going boats on this chart, like some that call locally on the ports of Seattle and Tacoma, the particle emissions from bunker fuel would be way off of this chart.
> 
> PS: certified wood stove is listed at the top of the range. 2-4gms/hr is more typical.




There are a few things that the graph does not take into account. For instance; extraction and transportation pollution, which you would think would be quite a bit more for some of the fuels listed.


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## darkbyrd (Jan 26, 2011)

If we're talking about CO2, wood-burning appliances are carbon neutral, tree growing absorbing CO2, yadda yadda yadda. Stove wins. Particulates a different story depending on stove, fuel, methods, more yaddas. Car wins (probably). Extra helping? Chili, hands down.

But if we really want to get into it, you need to look at production and transport of the firewood. I make all my own stove wood, and between the saws, splitter, and tractor, I'm at the gas station once a week. And that fuel is not carbon-neutral.

2-man saw and a maul, now we're talking! 

EDIT: B-BAR beat me to the 'extraction and transportation' part


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## Jutt77 (Jan 26, 2011)

FyreBug said:
			
		

> Back from the break... First of all there were some mention as to CO2 is a pollutant or not. It depends on how you define a 'pollutant'. Just about anything can become toxic in high enough a concentration. Let us just say to assuage some sensibilities the terminology should have been "higher rate of CO2 emmission" although it's a mouthful. And please do not take this too seriously, this is just a fun exercise. There's too many variables but at least it provides a bit of a picture. All numbers are metric it's easier to calculate. So here we go...
> 
> 1L of gas gives off 2.88kg CO2 after combustion.
> Or volumetric mass of gasoline = 0.75
> ...



Good stuff.  This doesn't even account for CO2 emissions from the production and distribution of gas does it?


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## henkmeuzelaar (Jan 26, 2011)

FyreBug said:
			
		

> And now for some slightly useless information.
> 
> 15L of gasoline will emit : 43,2kg of CO2
> 28.12kg of wood : 4.22kg of CO2
> ...




I know this is all in good fun. Moreover, like most forum members, I do not consider burning harvested deadwood (or livewood replaced by new seedlings) as adding net CO2 to the atmosphere. Therefore, my only comment about FyreBug's calculations is that complete combustion of wood (at 20% moisture content) is going to produce roughly 10 times the amount of CO2 stated. Probably just a decimal point.....but who cares??   

However, particulate matter emissions are threatening to become a much, much bigger issue. At the rate PM regulations are expanding worldwide (spurred by secondhand tobacco smoke and urban traffic PM health effect findings) most of us may well see a time that our children or grandchildren will no longer be able to sit around a campfire at school, scout or other youth camps because the organizers don't want to be liable.... Sorry, just realized I am going off topic. 

To stay on topic: the proposed new EPA regulations still appear to allow approx. 10 times higher particulate matter emissions from stoves burning wood than from car engines running on a comparable amount (energy-wise) on diesel fuel. Although this may not sound too bad, one has to take into consideration that, in contrast with tobacco smoke and traffic-dominated urban PM, there are few if any reliable studies directly tying population-wide health effects to wood smoke (not talking about people with allergies or other uncommon predisposing conditions here).

I have researched pyrolysis/combustion processes as well as pollutant/health issues intensively for more than three decades and strongly favor a pro-active government role in protecting community health.  However, what is urgently needed here are some relatively simple studies that can show whether it makes any sense to lump wood smoke in with the tobacco smoke and/or urban traffic PM threats. Oops, going OT again.......

Will try to bring some of this up in a separate thread, at some point.

Henk


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## littlesmokey (Jan 26, 2011)

Does anyone else have a problem the figures? Who did the testing on what machines? Based on what it says, most of the data doesn't meet EPA standards, especially the stoves, right???


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## remkel (Jan 26, 2011)

I am voting for a coal fired car without scrubbers.


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## phatfarmerbob (Jan 27, 2011)

like i said .. electric cars ie: the volt , and the new nissan leaf,  are pretty much coal fired i mean if you burn the coal to make the electricty isnt that like having a coal fired car?  just playing devils advocate.


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## Hanko (Jan 27, 2011)

who cares


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## henkmeuzelaar (Jan 27, 2011)

littlesmokey said:
			
		

> Does anyone else have a problem the figures? Who did the testing on what machines? Based on what it says, most of the data doesn't meet EPA standards, especially the stoves, right???



If you are referring to roughly estimating the CO2 yields per unit weight of wood, one does not need much testing since the chemistry is fairly straightforward as long as we are talking *complete* combustion: e.g. using a catalytic or thermal afterburner stove.

The literature says that wood contains approximately 50% carbon, on average. So, FyreBug's 28.12 kg of wood contains approximately 14 kg of carbon.

When carbon (atomic weight 12) reacts with two atoms of oxygen (atomic weight 16 each) the resulting CO2 molecule has a molecular weight of 44.
In other words, 1 kg of carbon produces 44/12 (3.667) kg of CO2 and 14 kg of carbon produces 14 x 3.666 = 51.333 kg of CO2.

Because there are always small carbon losses to other combustion products (creosote, soot, VOCs, CO), it seemed that FyreBug's CO2 weight (4.22 kg) could perhaps be off by a factor 10.

Henk


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## Backwoods Savage (Jan 27, 2011)

It matters not to me which is more polluting. I occasionally have to drive the car and I heat with wood and will continue to do so, albeit in a very efficient stove.


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## littlesmokey (Jan 27, 2011)

GIVE US THE DAMN RECIPE, so we call all polute equally. :coolgrin:


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## jensent (Jan 27, 2011)

Off topic but here are figures for various home heating fuels from The Forestry commission in GB.

                                           Kg CO2 per KWH
  Wood logs,chips pellets             0.025   (modern EPA stove or not!)
  Coal                                        0.291
  Natural gas                              0.194
  Oil                                          0.265
Thanks,
Tom


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## littlesmokey (Jan 27, 2011)

jensent said:
			
		

> Off topic but here are figures for various home heating fuels from The Forestry commission in GB.
> 
> Kg CO2 per KWH
> Wood logs,chips pellets             0.025   (modern EPA stove or not!)
> ...



O(K, so my British English is a little weak, and i speak American English, But the graph means Greek to me.


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## jensent (Jan 27, 2011)

littlesmokey said:
			
		

> jensent said:
> 
> 
> 
> ...




What the figures say is that coal,oil,and natural gas heat produce ten times the CO2 per given unit of heat as burning logs, chips or pellets.


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## henkmeuzelaar (Jan 27, 2011)

jensent said:
			
		

> Off topic but here are figures for various home heating fuels from The Forestry commission in GB.
> 
> Kg CO2 per KWH
> Wood logs,chips pellets             0.025   (modern EPA stove or not!)
> ...



These British values for CO2 production from wood are meant to report carbon footprint data and already incorporate a more than 90% offset for renewable carbon fuels. The reason they don't totally offset wood as "carbon neutral" is that wood decomposition is a slow process, so that burning dead wood may lead to a temprary acceleration of CO2 released to the atmosphere. Moreover, some of the live wood might not have been replaced by new seedlings.

When using one of the straight CO2 calculators on the web, you will find approx. 1.7 kg of CO2 produced per kg of wood and 2.5 kg or more CO2 per kg of coal.

Henk


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## Adios Pantalones (Jan 27, 2011)

Not a lot of people are processing wood without the aid of fossil fuels in saws, trucks, etc


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## begreen (Jan 27, 2011)

True indeed. There's no free lunch. And don't forget the post processing pollution. Beer can be a mighty source of methane for some folk.


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## Texas Fireframe (Feb 12, 2011)

Hi! Do you have a link for this graph you posted? Just curious what the source is.

Is trailnotes your website? Great idea.



			
				BrowningBAR said:
			
		

> *Source: * *Emissions in Grams/hour or day*
> Cigarette                                              *.4 grams/hour (0.8 grams/pack)*
> Gas or Propane Furnace                    * .001 grams/hour ( 0.024 grams/day)*
> Oil furnace                                          *.02 grams/hour (0.48 grams/day)*
> ...


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## BrowningBAR (Feb 12, 2011)

Texas Fireframe said:
			
		

> Hi! Do you have a link for this graph you posted? Just curious what the source is.
> 
> Is trailnotes your website? Great idea.




I do have a source for that info... somewhere. I'll try to find it again. And yes, TrailNote is my (and my business partner) website. I'm glad you like. Just trying to keep people safe.


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## TomB (Feb 12, 2011)

Side Bar...

How many trees do I have to plant to offset the CO2 I emit in my lifetime? Not to mention the methane and C02 created by the deer that run through my yard? 
We generally plant 100 to 250 new trees every year on our property to replace dead or dying trees. Does anyone else replant trees on their property? I hug my trees, they will eventually end up heating my house. Does anyone have any idea if this type of stewardship for Mother Nature would improve or offset the "carbon footprint" of burning wood creates? I love reading everyone's posts. Any throughts? I didn't mean to takeover this thread...

tom


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## Texas Fireframe (Feb 12, 2011)

TomB said:
			
		

> Side Bar...
> 
> How many trees do I have to plant to offset the CO2 I emit in my lifetime? Not to mention the methane and C02 created by the deer that run through my yard?
> We generally plant 100 to 250 new trees every year on our property to replace dead or dying trees. Does anyone else replant trees on their property? I hug my trees, they will eventually end up heating my house. Does anyone have any idea if this type of stewardship for Mother Nature would improve or offset the "carbon footprint" of burning wood creates? I love reading everyone's posts. Any throughts? I didn't mean to takeover this thread...
> ...



That is incredible. How much acreage do you have? And do you only burn dead or dying trees?


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## webbie (Feb 12, 2011)

TomB said:
			
		

> Does anyone have any idea if this type of stewardship for Mother Nature would improve or offset the "carbon footprint" of burning wood creates? I love reading everyone's posts. Any thoughts? I didn't mean to takeover this thread...
> 
> tom


A  lot of this is a big picture item.

Our state, for instance, has much more forest than in the past couple of hundred years! This is true of many areas because wood and charcoal are not used as much for heating, smelting and building.

Whether those trees are on my property or on the conservation land behind me makes little difference. They are all eating CO2 and pumping out O.

In a general sense, wood has no carbon footprint (or a balanced one), and given the rise in forest and other woody growth, it's probably a net gain......because so few people really burn wood. 

No doubt, however, that the more open spaces and forests we leave.....and even cultivate (good forestry) adds to the positive side of the equation.

Burning wood for residential heat would not be a good thing if everyone did it......but the same goes for lots of other practices. The give and take have to be somewhat equalized.


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## Fsappo (Feb 12, 2011)

More importantly, which is faster, a tree or a rock?


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