Photosynthesis.

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Happy Birthday Babe.   One of the standard denier arguments is that CO2 is not a pollutant; that more of it in the atmosphere will make agriculture more productive. That it's a good thing to be increasing CO2 emissions. The more the merrier! I thought how neat it would be if photosynthesis were self-limiting - in the manner, say, of population curves. It's easy to see the appeal: if something as fundamental as photosynthesis began to grind to a halt because of excess CO2 the world would immediately take notice. But it doesn't. Oh well. :-) In the process of refreshing my memory on photosynthesis (which I had from Melvin Goldstein & Rolf Sattler at McGill in an earlier life) I noticed how often we take things for granted. The diagram at the left f'rinstance - the primary exhibit in the Wikipedia entry - has no starch or sugars! And consequently no polysaccharides/many-sugars such as cellulose which are how this amazing self-bootstrapping process builds the very factory that it operates within. And nothing makes sense without that! The diagram at the right is more complete. But ... ... in order to understand the limiting factors it is also necessary to understand that photosynthesis is a (broadly) two-stage affair: one set of reactions dependent upon sunlight and a second set - the Calvin Cycle - involving CO2 which are not light-dependent. The third diagram (below) covers this off - with the added bonus of introducing ATP - Adenosine Tri-Phosphate - so bringing phosphorous, another essential element which humans are relentlessly squandering, into the picture. There are limiting factors - they just do not work the way I hoped they would. Photosynthesis: Limiting Factors: These graphs have no scales. The limits are a complex set of interdependent relationships so the flattening of the CO2 curve is not (only, so much) because of CO2 concentration but because of the other factors. The peak on the temperature curve looks promising but it doesn't kick in until the enzymes begin to denature (which I am thinking comes after climate change is no longer an issue for H. sapiens :-). So much for simple answers. On the one hand we have experimental results showing ~50% increase in photosynthetic activity with doubling of CO2 and on the other, estimates of decreases of ~10% per °C increase in average global temperature (not related to photosynthesis but to a variety of climatic and biologic effects). No wonder some of the deniers are confused! So am I. :-) It's easy to see how some prototypical student/scientist could be captured and spend a happy lifetime in the complexities of it - so many beautiful tendencies, such variety of detail, so many pathways, convergent evolution towards C4 modes an' all. While for fruitcakes like me (in our seven-league boots) it's just a hop & skip from the varieties of chlorophyll to our Percy out looking for the Grail. The Grail as a green stone: There is a tantalizing (un-footnoted) remark in the introduction to the Helen Mustard/Charles Passage translation of Wolfram von Eschenbach's 'Parzival': "How does it happen that the 'Grail' is neither 'Holy' nor a chalice, but a kind of green stone?" For someone who has read 'Parzival' and evidently not noticed it is a shock to even consider revising grail imagery away from a chalice or cup (with related connections to feminine genitalia &c.). This notion of a green stone is taken up exhaustively by Ronald Murphy in 'Gemstone of Paradise: The Holy Grail in Wolfram’s Parzival'. Evidence that Eschenbach made it a stone is found in his own text (469: "... a stone whose nature is most pure. If you know nothing of it, it shall be named to you here: it is called lapsit exillis. By that stone’s power the phoenix burns away, turning to ashes, yet those ashes bring it back to life."). Evidence that it is green is about entirely circumstantial. Ronald Murphy is a Jesuit - maybe that has something to do with it. In the meantime I started writing this odd sort of birthday greeting; hareing off after the greenness (which appeals to me every bit as much as it appeals to Ronald Murphy :-). "May I look?" asked Maskull; and, without waiting for permission, he picked it up. It was a delicately beautiful egg-shaped crystal of pale green. "Where did this come from?" he asked queerly. Panawe turned away, but Joiwind answered for him. (David Lindsay 'A Voyage to Arcturus' Chapter 7: Panawe) The green sparks from the brook, when closely watched, could be distinguished individually, each one wavering up toward the clouds ... (David Lindsay 'A Voyage to Arcturus' Chapter 16: Leehallfae) Even some scripture: "And Samson said unto her, If they bind me with seven green withs that were never dried, then shall I be weak, and be as another man." (Judges 16:7) which brings us to the Kryptonite side of things (I will come back to this in the next post). Eschenbach's Grail story has great (and enduring - nine hundred years already) power because of Percy's fallibility: he get's within an ace of the Grail and has 'the question' right on the tip of his tongue but doesn't speak it - and so must endure another round or two of terrible travails before he gets a second chance. And what is this ultimate and so momentous question? It is no more than "What ails thee?" How mundane! A trite formula repeated a dozen times a day by most of us - "Hey man, how'zit goin'?" - and the answer, if there even is one, most often ignored or forgotten. A misogynist? Someone who cannot calm a crying baby? Who makes inappropriate (but unspecified) remarks to young children? Such judgements (and not just these but more and from all sides) have cut me to the heart, sickened me. Taking a kind of refuge in John Donne, so wise: "As Sicknes is the greatest misery, so the greatest misery of sicknes, is solitude; when the infectiousnes of the disease deterrs them who should assist, from comming; even the Phisician dares scarse come. Solitude is a torment which is not threatned in hell it selfe."         (John Donne 'Devotions upon Emergent Occasions and seuerall steps in my Sicknes.          Meditation V: Solus adest. The Physician comes.' 1624) Now you may think I am making this 'all about me', or being unkind, but neither is the case. Either you think it through or you do not. I have no force to apply, no suasion, no fulcrums - only love. I'll leave it with you. Postscript (2nd):    I am often up all night; killing the midges that flock to my desk-lamp at this time of year with my fingertip. A few weeks ago, a week ago ... sometime recently ... I noticed that it was exactly 4:07 AM when the birds began to sing; and then it was exactly 4:02; and THEN one morning at 3:54 I held up my baton, my wand, and mentally said, "Hit it!" and they did. Delightful! Today I have got up specially to hear it (3:53). And a sentimental tune comes to the memory of my ear ... "I'll be looking at the moon ... but I'll be seeing ... you." 3rd:    Having a smoke on the bench just before nine (when the library opens); the sparrows are hopping round my feet and one of them settles for a moment on my knee. Ah!    (Now it's all Chaucer & Cohen but then it's ... "Ah!")

 
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