The third warming

It’s an old saying that wood warms you twice  – once when you chop it up and again when you burn it.  But the evidence is strong now that it warms you three times.

We had a load of seasoned timber delivered the other day and moving it in a wheel barrow to a dry shed certainly kept me warm in the drizzly weather.  And the other night watching the snooker on the TV with a log fire burning was a warming and comforting experience.

But maybe it shouldn’t be.  I’ve always assumed that I was doing the right thing by burning wood rather than coal because, of course, wood is a renewable resource and provided somebody replants the timber that I have burned then the carbon released from my fire will be sucked back into another growing tree and so this is carbon recycling not just carbon release.  Whereas with coal it will be millions of years before the carbon released quickly could be recaptured in new coal deposits – if at all.

But black carbon, soot to you and me, is an important cause of global warming.  My wood fire isn’t the main cause but my diesel car won’t be helping and generally speaking wood burning is a big problem.  Here are some links for more information (here, here, here).

Now what I don’t know, and I wonder whether anyone can tell me, is what the relative impacts of coal (which must be a bad thing to burn), wood (which it seems as if is nowhere near as good a thing as I had previously hoped) and putting on the central heating a bit more might be.

Like all other green decisions this one is more complicated than at first it seemed. An open fire is nice, it is sometimes where we can roast chestnuts and it does mean that the heating is low everywhere else in the house.  I am, as almost always, confused about the right thing to do.


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12 Replies to “The third warming”

  1. Mark, the solution is actually quite simple - as the UN report pointed out under cover of its alarmist headline - modern wood boilers emit hardly any soot, unlike our open fires which I'm afraid I'm going to go on using anyway ! My small domestic woodburner is much better - for heat and soot - than an open fire, but still not in the league of a modern heat boiler. They burn at over 90% efficiency (note that co-firing power stations without heat capture is less than 50% efficient) with very low emissions. Unfortunately, they work best from 30 Kw upwards, a bit big for either of our houses - but great for buildings like schools. Getting it right for once, the Government Woodfuel strategy is aimed firmly at this market sector (no subsidies for small woodburners), also keeping it local and reducing 'wood miles' because the Renewable Heat Incentive payments drop right off over 500kw. So the miracle of wood is matched by another, far bigger miracle: a Government renewables policy that gets it right for the whole environment.

  2. Mark
    I presume that you enquired about the provenance of your load of logs. Due to the high price of all fuels including logs, certain businesses around here buy in logs from landowners and then retail them. Problem is that landowners requiring a bit of cash can just go ahead and cut down a small woodland with out any consideration of replanting. The net result of this is a net input of CO2 into the atmosphere.
    If a woodland is planted for wood fuel on a cyclical basis then the net gain of CO2 into the atmosphere should be zero.
    Trouble is that we can also end up with no dead or fallen timber in the greater countryside, because of it's high monetary value. Also those tree in the middle of a field where once there may have been a hedge now have a high value which may just tip the balance as to whether they are removed or not.

    1. DavidH - i do know the provenance and my money is going into the pocket of one of the largest landowners in Britain. I am pretty sure that the woodland management of this particular estate is goiong to be of a high order - it certainly looks it as aI drive past.

  3. Imagine my quandry then, Mark. I have a house here with oil-fired central heating, and a large efficient stove that will burn pretty much anything I care to put in it. Our heating oil must have the biggest carbon footprint of any in the UK - even before it's burnt, it's had to be freighted up here to the Northern Isles. Carbon notwithstanding, it's eyewateringly expensive to buy.

    On the other hand, there is abundant peat literally on the doorstep - cut traditionally by hand, it's free, and the stove can heat the entire house in the evening, pumping out heat well into the following morning, and as an added bonus has a hotplate on top so I can boil the kettle for an evening cuppa without using mains electricity. But we all know extracting peat is bad... (Though, in the same way as we replant trees to replace the burnt timber, the turves from the top of the peat moorland are laid on top of last year's digging, allowing the peat formation to continue - and indeed, one can see how decades old cuttings are noticeably higher than more recent cuttings). Somehow though, it doesn't feel quite right.

    Alternatives? Night storage heating from the mains electricity... but we're not actually *on* the mains, the Northern Isles being off the national grid, so our electricity is in the most part (80%) generated by a power station run on diesel. Nasty, sooty diesel that, you guessed it... has to be freighted up here. That can't be a better option.

    The 20% electricity that isn't diesel-generated comes from 5 wind turbines - the most productive (albeit small) wind-farm in the world. It's very windy here, year-round! Building an on-shore windfarm here would seem to make great sense for generating green electricity, not just for the Northern Isles but (with an interconnector to the mainland) for the UK as a whole. But those turbines will have to be built on peat uplands (albeit largely despoiled by decades of over-grazing by sheep). Is that acceptable?

    Which just seems to leave micro-generation. I can't afford to install a ground-source heat pump, and tales of their efficiency (or lack thereof) abound. What's to be believed? Domestic wind turbines might be okay in the more temperate south, but living up here I see firsthand how frequently they break down in our extreme climate. They're just not good enough to warrant the (again unaffordable) investment.

    I can't help but keep coming back to burning peat to heat my house...

    1. Jon - yours is a very particular case of a modern dilemma. Most people won't give it a thought and those of us who do find themselves torn and sometimes doing the wrong thing through good motives.

  4. Beechwood fires are bright and clear
    If the logs are kept a year,
    Chestnut's only good they say,
    If for logs 'tis laid away.
    Make a fire of Elder tree,
    Death within your house will be;
    But ash new or ash old,
    Is fit for a queen with crown of gold.

    Birch and fir logs burn too fast
    Blaze up bright and do not last,
    it is by the Irish said
    Hawthorn bakes the sweetest bread.
    Elm wood burns like churchyard mould,
    E'en the very flames are cold
    But Ash green or Ash brown
    Is fit for a queen with golden crown.

    Poplar gives a bitter smoke,
    Fills your eyes and makes you choke,
    Apple wood will scent your room
    Pear wood smells like flowers in bloom
    Oaken logs, if dry and old
    keep away the winter's cold
    But Ash wet or Ash dry
    a king shall warm his slippers by.

  5. I wonder if these modern heat boilers use wood chips as some do now,if so in a way they are the worst option as there is a lot of energy put into getting long logs then chipped and dried before finally carted to destination.
    Usually come on here for answers Mark but today very confused but we do like our multi-fuel stove which seems very efficient would guess for about £200 and £30 on coal it provides half our heat for the winter.One big plus is that the logs are almost exclusively the outside of trees used for timber for various buildings etc.

  6. Agree with all the confusion. I usually just suck it up and stick more layers on. I think we're all pretty aware of our home energy usage by and large owing to the financial reality of energy prices.

    I find particularly disturbing the waste of energy in workplaces. I'm sure some are well managed but where I work I spend the day being roasted alive by my office mates. My employer spends well over a million quid a year on energy and there seems to be little thought to how that should be managed.

  7. I agree Dennis. Why cut a log up in to chips and then form it back into a sanitised and uniformly sized compressed log at an enhanced price. Totally crazy and this does happen.
    And to Jon yes please continue using locally produced peat you are diversifying the wildlife habitat by producing wetter areas which can be used by aquatic plants and animals and it is certainly greener than oil produced in the shetland area being sent south to be refined and then returned on a lorry transported by ferry from Aberdeen. And besides all of this global warming is a load of tosh anyway, is it not?

  8. David H - loss of woodland & dead wood are two real concerns, but neither are real threats in England at present: legal felling controls are ferocious and the public very, very good at reporting suspicious felling. As the Woodland Trust points out, most woodland loss is legal and sanctified by the soon to be further relaxed planning system. Dead wood is a real issue and the assumption that its fine to collect dead wood off the forest floor is wrong - BUT with over 500,000 ha (nearly half) of woodland currently unmanaged in England we're not about to run out soon - in fact we're accumulating dead wood fast, at the expense of early succession species like Dormouse, woodland fritillary butterflies, Nightingale and bluebell - lack of management is the top reason for declining woodland birds.

    On the energy, even I was surprised to be told by the FC's climate change expert that the energy used to harvest & process wood (including chipping) is less than 5% of the carbon value in the wood - I'd have guessed closer to 10%. That compares with 70 % for the mad biofuels from oilseed rape that Mark & RSPB are rightly fighting against ! And the answer is to haul as short a distance as possible - which is why the Woodfuel Strategy aims for local use.

  9. from something I wrote a while ago...
    Many recent discussions on cutting soot emissions have highlighted the contribution from biomass stoves, widely used in the developing world. But these also emit other aerosols which have a cooling effect, because they reflect incoming sunlight.
    “From a climatic perspective, a growing transport fleet employing uncontrolled diesel engines and residential and industrial coal use are of greater concern,” the authors say.

    Not sure where open log fires fit in that though, and they are lovely to sit next to!


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