A Carbon Fixation.

[This is another slightly older text – 2009 – now updated, combed through and, I hope, broadening the contexting of present goals]

Anthropogenic atmospheric carbon is spoken of as released annually on a 60:20:20 basis, as close as we seem able to determine, as industrial carbon burning (including power generation and vehicle use) : farming : forest clearance. These days the annual release is in the order of 30 billion tonnes in total.

I would argue that the three contributors to climate change must not be linked together in our addressing of them, as they are radically different to each other in their nature.

  1. Industrial. Currently being targeted by the “carbon credit” market in differing assignations in the developed World, as I’ve covered often before. This is economics fighting economics and, I guess, economics will probably win. I could expand on this point but, suffice to say, this time,  that the approach is indirect and has questionable outcomes.
  1. Agricultural carbon. Currently being almost totally ignored on the grounds that there are so many of us and so many are starving that we must not even criticise farmers, let alone put further constraints upon them. As they tend to be a powerful lobby group they can respond to or even forestall moves to guide them in new and more sustainable directions. Agriculture has always been established by clearing the natural ecosystems and this process continues today. Slash and burn rotational land use has been eclipsed by slash, burn and settle. As bees will concur, pesticide use is quietly extending this clearance to this very day even under our noses in a most sinister manner. Additionally is the more obvious continued and rapid destruction of tropical rainforests.
  1. The above ongoing forest loss produces some 20% of annual release of carbon to the atmosphere. There is evidence, in the research and writings of Dr Simon Lewis (Leeds) and others elsewhere, who suggest an opposite movement of carbon into the remaining forests through their uptake of additional bulk, over and above that which they would normally use. They talk of an additionality of say three to four billion tonnes of carbon per annum.  This is equivalent to a couple of million hectares growing at full pelt eg post coppicing or early maturity of planted forest. An area akin to that of Wales. These do not exist and they envisage this growth incorporated into the sustainably increased bulk of existing mature forests. On an annual basis. As remaining forests shrink. No further comment is necessary at this point!.

Measurements have, however, provided a substantial anomaly in the annual carbon balance sheet as, although it can be demonstrated that the above listed three anthropogenic sources produce thirty billion tonnes carbon dioxide release each year, only half of this amount stays there. The absorption of some 15 billion tonnes of atmospheric carbon annually by the natural global system does, then, require understanding.

There are a number of “sinks” which include forests, of course, as part of the sustained transfers of the natural ecosystems. Organisms live, breathe, photosynthesise, die and eat each other in the natural order of things of course and every school kid can draw a carbon cycle. Put figures for the bulk transfer of carbon from one form to another annually and it totally dwarfs the anthropogenic contribution. But they are in balance and we’re tipping it. This is the basis of all the climate change discussion and must be understood when seeking solutions.

Crucially, it seems, we must try to restore a balance. This requires a multi targeted approach and needs some further background information. Unclear, as implied above, is the “half-life” of additional atmospheric carbon. We know that its level naturally changes, as witnessed by data from ice core samples, ocean Foraminifera deposits and so on. These lead to a conclusion of the last thirty years having led to a very unnatural high which is ever increasing. The data are hard to quibble with and are generally accepted as benchmarks for discussion.

Carbon is absorbed in photosynthesis by plants and into oceans by inorganic chemistry. Dissolved in rain water, as carbonic acid, it reacts with lime and limestone, probably with net carbon absorption from the atmosphere (essentially the same as at sea). Otherwise further atmospheric chemistry can also associate and dissociate the carbon compounds and clear them from the air. If no fossil carbon were released into the atmosphere from today, how long would today’s too high level remain constant?

It’s a trick question, of course, as there would still be forty percent of present release through agriculture and forest clearance, which instantly shows up the flaw in the conjecture! Anyway, if no fossil carbon use then how do forestry and farming continue? If, we assume no continued additionality then one conjectures that natural sinks could remove the excess.

In fact, at the present rate of loss to sinks the thousand magatonnes of accumulated anthropo-generated carbon dioxide would be removed in just under seventy years

 (This also ignores the result of removing anthropogenic particulates from the atmosphere. This ever present shield seems to absorb or reflect solar radiation in the atmosphere and so protect from effects of further global warming. Maybe. Sort of. Well, it was observed when planes were grounded post 9/11 in the USA.)

 

OK, so can we both shut down and wait 70 years? The first is an obvious “No” but the second sounds almost reasonable. Back to sustainability for the grandchildren of today’s youngsters. And the interim? Continued anthropogenic climate change and, realistically, we’re only going to cut  carbon release by a fraction and only a good few years down the line.

In which case the total carbon load will continue to increase. And let’s look at the present removal of fifteen billion tonnes over and above natural carbon fixation (“background”). Wherever it’s going, it is over and above the natural tolerance. At ecological stasis it should no longer be net flow, or there’d be no stasis, no mean. We would soon be in atmospheric carbon poverty.

If, in the middle ages, fifteen billion tonnes had been lost to the atmosphere on an annual basis then it would all have gone in 170 years. Plainly that didn’t happen so what limits matters now? One should handle this issue with care – as any tightrope walker knows, balance needs hard work to be maintained. (Although they might also say “Don’t think about it as you maintain your balance naturally”!)

The concept of “dynamic equilibrium“ is ecological truism. There is never any stasis and yet this maintains balance. You see it as seasons progress and different species appear and prosper at the time most suited to their physiologies. By day and night, too, and as the decades progress. Have a mini ice age and the species mix changes. Tree archaeologists can demonstrate such movements up and down North America of coniferous and deciduous trees over ten of thousands of years. Obviously it’s a whole lot easier for more mobile animals.

As with living materials, so also with the physical components. Remove a soil nutrient and the plants die, decompose and release the nutrient again. Meanwhile the animal population has drifted away and saprophytes, fungi and the like worked on the recycling. Then, yes, seeds germinate, new plants grow and the animals return. Sorry, I labour the point but it’s important. I could even insert a graph or two to illustrate the affair. Homeostasis allows levels to fluctuate about an ideal. In fact the level rarely stands at that ideal, it is just the mean.

Is there a given carbon dioxide mean for our global ecosystem? Here one is in danger of rambling in a Gaeist manner but it is worth exploring – without any personification! Elevated levels of carbon dioxide should drive all the reversible reactions in the direction opposed to its concentration. Hence Dr Lewis’ theorised huge increases in forest bulk. Myself, I prefer to think of the dynamics of bicarbonate and carbonate formation as marine held carbon dioxide, but this, too, is fraught with myriad uncertainties. As I’ve discussed elsewhere, there is strong evidence of an ongoing, natural net carbon release from the oceans.

So, sadly, I cannot demonstrate a mechanism of  “dynamic equilibrium” to handle our current status as gross carbon releasers. Although there was an approximate stasis level and there were no net gains to trees or to the seas (presumably) we have no clear picture of even the destinies of the current atmospheric excesses, let alone their dynamics. If the ab or ad-sorption of fifteen billion tonnes per annum is a homeostasic mechanism, then we do not know how it was turned on or, indeed and worryingly, how it could be turned off!

Anyway, realistically, the atmospheric carbon level will continue to increase and, although the developed World will over coming decades reduce their inefficiencies of use, one is inclined to imagine that gross levels of consumption will be maintained or, even, increase – as has happened recently by displacement of manufacturing to China and such countries. Zimbabwe next, anyone? They’ve a wonderfully taciturn government so we should manage ten or twenty years there before we’re moved on. And I tell you labour is really cheap. You know ten for the price one – just give them some sadza meal.

No, I grant that carbon economics does have some effect, even if it only works “at home”. We must spread the proceeds wisely – intense insulation of heat leaking homes, for major example, that needs several billion (say 15) pounds urgently in the UK alone- but other approaches are needed if we are to restore a balance to our ecology, to a semblance of its natural state, and then supplement it with additional actions.

So let’s roll in the economists. First agricultural ones – how can you reduce the deterioration of marginal lands but also support large numbers of marginal farmers? Taxes? Subsidies? Free trade? Or even Fair Trade? And methane – livestock, paddy fields, beans? (OK, beans is a joke – sort of). Then there’s carbon rich arable – fertilisers, machinery and, of course, forest clearance. This area is such a warren I think I’ll move straight on.

To forests and the intense carbon trapping/harvesting vegetation of the World. At the present rate we have three hundred years of rainforest left, but remember global forest cover is already less than fifty percent of it’s original, optimal level. Where’s all that carbon now? Wherever, it’s mostly out of the cycle and its loss has increased the instability of our present state.

Some is part of today’s atmospheric levels. Let’s look at that fraction. You have to feel sorry for it because it’s homeless. That’s right, it’s got nowhere to go because we burned its terrestrial home and now, well it could fight to become a bit of a soya bean – but it’s so short term and, anyway, who wants to become methane or, even, prime Aberdeen Angus. It may just end up lost and inorganic – out of the schoolkids’ cycle.

Objectivity is a wholly subjective decision, isn’t it. Generally I’m objective and you’re subjective. Can’t you even see that? But here I do try to retain an observer’s view. You know, that of my putative Great Grandchildren. Planting trees one always has to think long term but this has double force. I can see that the issues I’ve discussed above have many unknowns.  (Go away Dick Cheney) and there is an inertia which always says “We’ll muddle through.” and “It might be awful, but we’ll be OK”. But to me it seems so clear that we must systematically organise to restore our natural vegetative carbon fixation on a Global basis.

It’s urgent as it is the only way to bring back the natural buoyancy of the system. If the forests were a natural buffer on carbon dioxide change then that protection is sorely diminished. The challenge is the mechanisms we could use. Economists? Nah, pigs might fly.

How about a separate Global Forest Credit, paid for increases in a county’s net forest cover and sustained. Tie this to a global fossil fuel extraction tariff and, maybe, some system of food exportation tariff used to support small farmers to work to feed local populations in a sustainable manner. Of course there should be a ban on any net reduction of forest cover, penalized drastically. I’m not sure how but it’d have to be fierce!

That’s it. Job done. Next problem? Medical mistakes? Oh, yes, well we’ll have time to think about that again, now. Now we’ve got a sustainable future!

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About greencentre

Non grant supported hence independent scientist, green activist, writer and forest planter.
This entry was posted in Buffering the terrestrial carbon cycle, Carbon market, Carbon sinks, Climate politics, Gaia, Green politics,, New forests and woodland, Rainforest. Bookmark the permalink.

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