Fossil fuels are carbon neutral if you can wait around a few aeons for them to replenish! Wood is really only regarded as renewable because it can be regrown in a human lifetime, but still, all you're looking at is "recycling on the macro scale". Eventually all those landfills will end up in the magma..

And then, consider that nothing is renewable, really, because it's powered by the sun and that's got a finite burn life.. we're just measuring it relative to our blink of history, with a dollop of social conscience regards making our children wallow around in the mire we created..

The fascination with wood burning stoves is pure traditionalism. We huntd and cavedwelled for hundreds of thousands of years but only farmed for a few tens of thousands. Burning things is intrinsic

I'd welcome your further comments, Simon and others.

Pollution monitoring is not my speciailist area, though dodgy stats in the media are a little more so.

From here that link looks like very dodgy reporting.

For the 12% claim we have:

"In 2009 coal and wood burning in the home was thought to be responsible for 12% of UK PM10 emissions [source - National Atmospheric Emissions Inventory], whilst research by King's College London suggests around 12% of the PM10 in London's air during winter 2010 arose from wood burning."

ie an average measurement from a wide area over a long period.

For the 50% claim we have:

"This is not to underestimate the contribution of traffic emissions but wood burning, according to the experts, was making up half of the pollution readings at some monitors at some sites - all exacerbated by low winds not blowing away pollutants."

which is *some* monitors at *some* sites ie a selection of peaks.

And the BBC making a direct and dramatic comparison:

"That is quite a leap from 12% to 50% in the levels of wood burning on Monday."

To me the 12% looks like a wide average and the 50% a handful of spikes as I say.

I expect the spikes were also there in the earlier figures, and average out to the overall "London" 12% number, and that the comparison is not valid in those terms.

Or am I misreading this?

Cheers

Ferdinand

Posted By: orangemannotOne should live forever.

One of the best places to live is in prison, very very few people die in one.
But that is just playing with geo-statistics.
The same is true of comparing diesel emissions with wood burning emissions, there are two parts to it:
Emissions per kWh delivered
Total Emissions

Where Emissions are whatever combustion or environmentally damaging substance you wish to measure.

So it is no good comparing say the reduction of natural resources i.e. diesel cars using less crude than gasoline cars, with PM10 and PM 2.5 particulates from wood burners.
Where it gets difficult is comparing the utility value of each energy source. For some people, driving is an economic necessity that cannot be got rid of.
Heating is a necessity for most people, and again cannot be got rid of.
So it comes down to the best (generally the cheapest) way to reduce emissions from each class of energy usage.
It would be pointless to spend £10,000 reducing household emissions by say 1 tonne, when for the same money you could reduce transport emissions by double (just made those figures up as a 'for instance').

I still fail to understand the argument that it is alright to burn timber in a low populations area. It is not acceptable to dump asbestos is a low population area, or kill a cat, or stop education of young people, so why should it be acceptable to allow a heating system to pollute the environment.

@Simon Still,
they (WBSs) can be used as 'lever' for Part L compliance, to squeeze over the line...

Carry fallen wood from the local woods or coppice your own trees with a solar-powered chainsaw and you're pretty sustainable from a COâ‚‚ perspective. Use commercially grown wood trucked from the other end of the country or across the Atlantic and you're less so - some numbers are needed to say how much by.

By sustainable I mean doing something which could be sustained for a very long time. There's an initial hit of transferring a small amount of carbon into the atmosphere but after that it'd be steady state in much the same way that animals eating vegetation has been going on for a while on this planet (~0.5 Gy) without causing a long-term trend in the composition of the atmosphere.

So if it takes say 20 years to grow a small size tree that may give you 50 kg of dry mass suitable for burning, does burning it in one week still count as sustainable? Are you allowed to burn anything else before a new tree has been regrown.
Or do you rely on a tree somewhere else putting on 50 kg of dry mass in that same week?

Some of you may know that I have been running a tree growing experiment for the last few years, and I am still measuring in grams and centimetres, not kilograms and metres.

Posted By: Ed DaviesHow many woodburners can be carried sustainably is a different question which I doubt simplistic experiments can answer usefully.

We can can answer that and it has been, by Prof Brian Cox for one. I think it was about 400 days to deplete the reserves at our current energy usage.

What does that mean?

Does it mean, as I'm guessing, that if we (the human race) tried to get all our current energy use from burning trees then we'd run out of trees on the planet in 400 days? If so, it's a completely useless statistic.

(Just to be absolutely clear: I think burning trees is a really bad idea but mostly for the particulate reasons. I don't see why a small amount of it done appropriately should necessarily be a bad idea for COâ‚‚ reasons.)

Posted By: Ed DaviesIf so, it's a completely useless statistic

More a metric.
It highlights two things, the vast amount of energy the world uses and that it would take about 40 years to regrow before we have another years worth.
The problem is that it is the slow growth rate and the poor conversion from sunlight to stored fuel. PV and wind are much better options. They take up less land area per yield.

I am not saying that we should carry on digging up fossil fuels, just highlighting that biomass is not the answer. Some technologies, such as AD are useful, but is really pretty small scale in the scheme of things (friend of mine is involved with a 6MW AD gas2gas unit from a creamery, it could be argues that not having the cream in the first place would be better environmentaly).

Morning Gents

Most urban wood burners are fashion/lifestyle choices rather than being installed as a considered choice for a heat source. Again I'd suspect that in many cases they will never save any money or be used particularyly efficiently. The green benefits are talked up by owners to justify having one, rwther than just admit they enjoy the cosy glow.
In rural areas the story is a little different, where wood may well be a homes primary source of space heating and maybe for hot water.
My mothers property (rural wales) used lpg and woodstoves for years, mainly because my late father was a carpenter joiner working from the barns, he milled logs and dried his timber on site, so there was plenty of effectively free wood.
She now relies on bought in forestry thinnings (15 tonne loads (wet)) which i process and is air dried on site. This feeds 3 wood stoves that satisfy the space heating for the property for probably 16 hours a day in the heating season. LPG used to do the sleeping hours , we took advantage of the RHI scheme to update the old gas system. And now have a pellet boiler.
Getting back on topic, from my experience and having spoken with many in the biomass industry ( sorting out burn/efficiency issue) there will be looming concerns in the future regarding emissions from wood stoves and in particular pellet boilers/stoves. Many systems installed under RHI , have been done so by companies jumping on the bandwagon selling equipment that in many cases is not the " light and leave" convenience they state and nowhere near as efficient overall as they suggest.
However the goverment don't really care, currently they are more interested in recording as much pellet/wood useage as possible in order to justify claimed greenhouse gas reductions. Emissions are currently of no interest. Once notional targets have been met , maybe this will change.

<blockquote><cite>Posted By: Ed Davies</cite>Orangemannot's comment is consistent with their other comments so unlikely to be intended as irony. I doubt I'm the only one to skip read with an eye roll though with a bit of sympathy on the burnt toast bit; that's the sort of bullshit that justifies people's cynicism about valid science.</blockquote>

Thanks Ed, that was my point. bullshit presented as valid science.
As for my perspective POV?
All things in moderation, especially moderation.
We drive a v. ordinary 6 year old diesel car, we also keep a 1998 "classic" roadworthy as backup.
I like diesel as a fuel, its simply safer.
I like KERO as a heating fuel, I understand it, and use it in moderation.
I dont mind rats, even on our doorstep, as long as they stay outside, mostly!
We waste ZERO foodstuffs, reuse stuff gleaned from skips etc, & live v. simple.
Essentially we dont participate in the consumer driven disposable lifestyle world.
I continue to be amused at people, professing a green agenda, looking to build on green field sites(without rats or habitat that might harbour a rat), an oxymoron if ever I saw one.
i.e unatural sanatized nature.
We are ALL part of the less than "perfick" natural world, this includes disease & death, especially if very premature babies and other very sick infants are very artifically kept alive, at horrendous cost.
But
Most of all, I simply will not buy into the "woodsmoke is poisonous", from most probably people living in overclean sterile homes using God knows what cleaning chemicals, artificial air freshners and personal hygine products, never mind the shite bought foodstuffs they may choose to consume.
Regards
Marcus,the hat

If a scientist who lives in a log cabin with no cleaning chemicals, artificial air fresheners and personal hygiene products and who only consumed organic food stuffs brought out a study that said wood smoke was poisonous, would you believe him?

Wot ringi said
I burn wood for my heating and DHW. Wood is supplied from my own 'on farm' forests and I have the space and time to season it properly. Mains gas is not an option and LPG is prohibitively expensive as is oil (which here is taxed much the same as road fuel)

So whilst I accept that burning wood causes (more) pollution than some other forms of heating at the moment I don't feel I have much of a choice.

The government here recently said that the air pollution in winter is 50% due to wood burning. However here there is also an economic issue as wood is cheaper than gas - if you discount the labour for chopping it up and for many this is the only option. Having said that brown coal burning for domestic heating which still happens here is a lot worse than wood as it is usually burnt on older stoves (and it stinks, you can smell it half a block away).

Yes - but so is the exhaust from gas boilers - and from the production process from PV and ST, not to mention the environmental cost of producing insulation (of any sort) which I have used to reduce the amount of wood I have to burn.

Posted By: Peter_in_Hungarybut so is the exhaust from gas boilers

Is it? I know you can often smell it (a sign of incorrect adjustment, like typical diesel vehicles) but at best natural gas produces near enough just pure CO2 and H20 - that's it's claim to fame.