I spent the whole day thinking about this barley and carbon thing. Mainly because I am bad at science but it didn’t distract me from the challenge. It just seems weird to me that someone can say that “the growing and processing of hops and malt into beer and whisky producing 1.5 per cent of Britain’s greenhouse gases” while another beer study seems to show that the net benefit of barley to the planet is not included in the greenhouse calculation. How can that be? I usually don’t fight these things. I usually line up, close my eyes and accept these things with an… err… open mind but you read stuff like this and it gets you thinking:
Over a 20-year lifecycle, the right species in the right conditions can absorb over 40,000 tonnes of CO2 per square kilometer. So a plantation of 100 square kilometers can absorb 4 million tonnes of CO2 over 20 years.
Which means that 100 square km can absorb 200,000 tonnes in a year. Or 2,000 tonnes per square km per year. Or, given that there are 247.1 acres in a square km, 8.1 tonnes per acre a year. Then there is the retention rate. If you look at footnote 24 (warning .pdf) , you’ll see that the equilibrium level of carbon in cropland soils ranges from a minimum of 17 tons per acre to a maximum of 36 tons per acre (the mean is 24 tons per acre). A mature forest, by comparison holds 140 tons per acre which makes sense if you think of the trunks and branches of trees as a carbon sink.
So, crops like barley retain about 17% of the carbon that a forest does. Do they absorb at the same ratio? I couldn’t find that fact. So, I am going with the 17% ratio for now. Which means that barley may well absorb 17% of 8.1 tonnes per acre per year. Or 1.377 tonnes. That’s a lot. And what does it have to stack up against? One acre of malt barley will make about 540 cases of beer and a 60-case pallet of beer produces more than one metric ton (a tonne) of greenhouse gases which means that an acre’s worth of beer production generates about 9 tonnes of carbon. But of that brewing production only 8.1% is due to the barley or 12% for once the barley is malted. Or 1.08 tonnes per acre. Which looks like to me that barley absorbs more carbon (1.377 tonnes) than it takes to get it into the malted state (1.08 tonnes).
Point? You don’t get beer from looking at a bag of malt. But the closer you do, the less and less beer looks like a drain on the environment than the 1.5% might indicate. Planting enough forest for a perfect carbon off-set looks interesting as that 8.1 tonnes a year carbon debt to an average of 240 tonnes carbon credit per acre of mature forest could give a brewery a little under 30 years of 540 cases or 25 barrels of annual production. Which means Sad Adams would have to plant 80,000 acres to off set 30 years of its 2,000,000… (sorry)… 1,999,999 barrel production. Or 2,666 acres a year. Or 10.78 square kilometres a year. Sounds like a lot. Until you consider the scale of tree planting in British Columbia.
I am sure that is all wrong. There must be an easier way to determine all this other than, you know, relying on me.
[Original comments…]
Maureen Ogle – May 26, 2009 10:41 PM
http://www.maureenogle.com
Has nothing to do w/the post, but saw this and thought of you and realized I don’t have your email addy. Also sent link to Andy, Jay, and Stan.
Article on ethics of [beer] writing
Alan – May 27, 2009 9:15 AM
Thanks Maureen – here is a better version of the link.
Alan – May 27, 2009 9:16 AM
And here is Stan’s take.
21stCenturyCavePainter – May 27, 2009 12:21 PM
http://beantownbrews.blogspot.com/
Great article – consumers tend to forget that even food-stuffs can have unnoticed or unanticipated environmental impacts. I just recently learned of Long Trail’s efforts to reduce their negative impact on the planet with their ECO Brew program. I wonder how many other breweries do similar sorts of things.
Steve lacey – May 28, 2009 12:19 AM
“Which looks like to me that barley absorbs more carbon (1.377 tonnes) than it takes to get it into the malted state (1.08 tonnes).”
Alan, the problem here is what happens to the carbon absorbed by the barley? In pretty short order it all ends up back in the atmosphere via yeast guts, our guts, pig guts, incineration, or composting…
When you look at the net carbon influence of natural systems, you have to look at the long term change in the sinks. Are they increasing, decreasing, or staying the same? In arable crops, the soil is the biggest sink and generally speaking is mostly in a carbon equilibrium (stable organic matter content). There was a big loss of soil carbon when land use changed from prairie or forest to farmland, but after that it found a new equilibrium. If, however, you can produce a crop in which the carbon absorbed by the plants is locked up long-term in an organic product, you have a chance of having a positive impact. With forest carbon sequestration, you have two chances of getting net sequestration: (1) if the soil carbon sink increases, and (2) if you can stop a large proportion of the product from decomposing, being burned etc. And of course the less processed it is, the better. Hence, forest carbon sequestration depends a lot on the fate of the harvested trees — paper, furniture –> incineration/landfill?
I can’t see any possible way that the production of foodstuffs can be seen as anything other than net carbon emitting processes. The barley growth/degradation is essentially neutral, but all the energy that goes into production, processing, packaging, and delivery are obviously going to be net carbon emitting. As much as we can hope for is that some businesses follow practices that emit less than they would if they didn’t give a damn (reduce, re-use, recycle).
Alan – May 28, 2009 8:53 AM
Alan, the problem here is what happens to the carbon absorbed by the barley? In pretty short order it all ends up back in the atmosphere via yeast guts, our guts, pig guts, incineration, or composting…
I think you missed my point. All Sam Adams needs is 300 square km of forest that it farms to offset all its current production through a natural carbon sink that is managed as a separate revenue stream.
Yes, the carbon is released but it is also captured because that is the nature of life. You can complain all you want that the Good Lord gave us bowels that create gas but that is life. It is about management not prohibition or you are getting into dangers territory about denying your biological fact.
Steve – May 28, 2009 9:52 PM
I think you missed my point. All Sam Adams needs is 300 square km of forest that it farms to offset all its current production through a natural carbon sink that is managed as a separate revenue stream.
Oops. In fact, it appears I did barely skim that last paragraph. Sorry.
If I recall from my days inside the forest industry, it costs about $1000-$2000/ha to establish a forest on already cleared land, not counting the cost of the land. So that’s $1-2 million a year for Sam Adams if they can find someone to donate the land. There are probably other hidden costs like a staff-member or three to oversee the process.
The graph of forest planting in British Columbia doesn’t mean much in the world of carbon offsets because it is referring to management of the forest estate. You can’t claim a carbon offset for tree planting unless you do it on land that has been continuously in non-forest use prior to 1992. In practice, you go into a landscape consisting of a mosaic of forest and cleared grazing land (say) and try to buy up or obtain leases for 1000 ha per year, I can tell you from experience (in NSW) that it is a pretty big task.
Interesting story about one of your countrymen who is a visionary and pioneer in the field of environmental offsets, which is straying well away from beer, but I can see you are interested in this topic.