Jy blaai in die argief vir 2013 Januarie.

Climate Change: The debate in Geobulletin (continued)

31/01/2013 in Uncategorized

Climate change – The Short Story (William McClenney) (continued)

Between 6,000 and 7,000 years ago, a period known to geologists and paleoclimatologists as the Holocene Climate Optimum, sea levels peaked between 1.5 to a maximum-found 8 meters higher than today (average in the literature seems to be about 2.5-3.5 meters), and during the Eemian Optimum some 20 meters higher than today. During the seven post MPT ice ages sea levels dropped some 100 or more meters below present, the water tied up in the miles-thick ice sheets that have spread in North America as far south as Kansas. These are just some of the facts of the abrupt climate changes which we, as Homo sapiens, have experienced.

General Circulation Models, of which the IPCC references 20+, have yet to produce a single known abrupt paleoclimate change fed with the proxy data. The latest GCM models produce predictions based on a variety of input data and complex equations which few of us understand. But for all the complexity and investment, they are still only predictions.

Belief in, and acting as a result of, such predictions has opened up what may be the first chapter of faith-based science.The astonishing enormity of natural climate change provides a harrowing appreciation of massive sea level ‘noise’ that can range to over 400 feet (with a beat of lesser, rank-and-file swings, think D-O oscillations) and temperature shifts that lord over all future fantasies you have yet heard.

What might be quite ironic is that if GHG predicted global warming is in fact real, and, at half of a precessional cycle, we are near to the cliff of the next natural shift to an ice age, we may find ourselves needing to generate as much GHGs as possible to ease our transition into the next ice age. So as I said at the beginning, doing something about climate change is not necessarily a bad thing. Doing the right thing might prove to be quite another. The ice ages and associated interglacials are well known to be paced by the eccentricity, obliquity and precession cycles in earth’s rickety orbit. These we will do nothing about. D-O oscillations show strong evidence of being tied to the 1,500 year cycle of solar output,something we cannot change.

Be ever thoughtful of both facts and predictions before leaping to a conclusion. It was in fact a LEAP that terminated the last interglacial, the cold Late Eemian Aridity Pulse which lasted 468 years and ended with a precipitous drop into the Wisconsin ice age. And yes, we were indeed there. We had been on the stage as our stone-age selves about the same length of time during that interglacial that our civilization have been during this one.

 

Climate Change: The debate in Geobulletin (continued)

30/01/2013 in Uncategorized

Climate change – The Short Story (William McClenney) (continued)

The climb out from the Last Glacial Maximum of the Wisconsin ice age (called Termination 1with sea level bottoming out about 121 meters below present) into the Holocene is studded with the Younger Dryas, a 1,300 year near instantaneous return to ice age conditions. “Briefly, the data indicate that cooling into the Younger Dryas occurred in a few prominent decade(s)-long steps, whereas warming at the end of it occurred primarily in one especially large step of about 8 degrees C in about 10 years and was accompanied by a doubling of snow accumulation in 3 years; most of the accumulation-rate change occurred in 1 year (National Research Council,2002)”. Far more suddenly we came out of it: “Taylor et al (1997) found that most of the change in most indicators occurred in one step over about 5 years at the end of the Younger Dryas, although additional steps of similar length but much smaller magnitude preceded and followed the main step, spanning a total of about 50 years (NRC,2002)”.

Termination 1 went into top-fuel, carbon-free overdrive with what is referred to as melt water pulse 1a (mwp-1a) centered at about 14,680 years ago which resulted in a 24 meter rise in sea level believed to have occurred at the rate of 4.5 cm a year. It was followed around 12,260 years ago by mwp–1b with a 28 meter rise nearer 5cm a year. Recent model results predict that sea level is currently rising at 32cm/100 years. If we take the low-end of the natural ‘noise’ clocked at 4.5 cm/yr (or 450 cm/century) we will have to kick in some serious turbos (carbos?) to net one and a half orders of magnitude boost if we hope to trump mother nature’s bottom bracket.

Another variable worth devoting some cpu time to is just how astonishingly well the fourth cycle of eccentricity matches up with hominid evolution.

“An examination of the fossil record indicates that the key junctures in hominid evolution reported nowadays at 2.6, 1.8 and 1 Ma coincide with 400 kyr eccentricity maxima, which suggests that periods with enhanced speciation and extinction events coincided with periods of maximum climate variability on high moisture levels.” state Trauth et al (2009) in Quaternary Science Reviews. There is just nothing quite like having such a natural fly land in your climate change soup. As it turns out, periods of wet maximum climate variability (in modern lingo, global warming/global cooling correctly re-branded as climate change), cook-up the larger braincases. We went from 500-550 cc braincases 2.8 mya to the average of about 2,500 cc today in the most rapid encephalization of any mammal in the fossil record.

Climate Change: The debate in Geobulletin (continued)

28/01/2013 in Uncategorized

Climate Change – The Short Story ( William McClenney). (continued)

A reconstruction from fossil algae in sediments from Drought Lake in North Dakota of the past 2,000 years found that dry conditions were far and away the rule in the High Plains, with the Dust Bowl conditions of the 1930’s one of the lesser dry spikes found in the record. Half of the warming that brought us out of the last ice age (the Wisconsin) occurred in less than a decade. There were 24 Dansgaard-Oescher oscillations between this interglacial, the Holocene, the interglacial in which all of human civilization has occurred, and the last one, the Eemian, in which the first fossils of Homo sapiens are to be found. D-O oscillations average 1,500 years, and have the same characteristic sawtooth temperature shape that the major ice-age/interglacials do, a sudden, dramatic, reliable, and seemingly unavoidable rise of between 8-10 degrees C on average, taking from only a few years to mere decades, then a shaky period of warmth (less than interglacial warmth), followed by a steep descent back into ice age conditions. Each D-O oscillation is slightly colder than the previous one through seven oscillations, then there is an especially long, cold interval, followed by an especially large, abrupt warming up to 16 degrees C (a Bond cycle). During the latter part of the especially cold intervals, armadas of icebergs are rafted across the North Atlantic(Heinrich events), their passage recorded reliably by the deep ocean sediment cores which capture the telltale signature of these events in dropstones and detritus melted out of them.

We know with absolute certainty that these events happen, with evidence of D-O oscillations extending back some 680 million years. We do not know, yet, precisely what causes them. What we do know is that the past six interglacials (dating back to Mid Pleistocene Transition) have lasted roughly half of a precessional cycle, or currently 11,500 years, which just happens to be the present age of the Holocene. What we know is that N65 latitude insolation values are very close now to what they were at the close of the Eemian. What we also know is that GHGs (Green House Gases), like us, seem to have played only a spectator role to all of these alarming natural transitions, with temperature changes leading GHG concentrations by a considerable margin of time (800-1,300 years). What we do not know is if the reverse could occur, anthropogenic sourced GHGs triggering a climate change event, for perhaps the first time ever. What we do know is that earth’s climate is bimodal, cold 90% and warm 10% of the time for the past million years or so, with the transition times (such as at the end of an interglacial) well known from proxy records to be quite sensitive to forcings we do not yet understand, and the forcings we have identified seemingly incapable of producing the responses we see in the paleoclimate record. Including the recent paleoclimate record.

(to be continued)

Climate Change: The debate in Geobulletin (resumed)

28/01/2013 in Uncategorized

Anna het oor die naweek in die Kaap gekuier en is op pad terug op die Interkaap-bus, trek nou seker al verby Springbok. Soos ‘n groot hond is ek geneig om so vas te slaap dat ‘n wekker of selfoon-oproep my nie sommer sal steur nie. Terwyl ek nou wakker is is dit ‘n goeie geleentheid om te blog, terwyl normale mense nog slaap.

Ek het in ‘n reeks poste berig oor ‘n debat in die “Geobulletin”, kwartaalblad van die Geologiese Vereniging van S.A., oor klimaatsverandering. Dit het in die Desember-uitgawe begin met ‘n brief deur Rose Prevec wat meen “deniers” hoort nie in die debat nie. In die Maart-uitgawe het John Trusswell (skrywer van universiteitshandboeke oor geologie) en ek (word genoem in “A Century of Geological Endeavour in Southern Africa, 1895-1995”), haar standpunt aangeval. Sy het repliek gelewer in die Junie-uitgawe, waarop my en John Trusswell se replieke in September geplaas is. In September was daar ook ‘n bydrae deur emeritus-professor John Geissman (VSA) en ‘n verwysing deur die redakteur van “Geobulletin” -albei glo in AGW. In die Desember 2012-uitgawe lees die laaste paragraaf in ‘from the editor’s desk’ soos volg:

“The ongoing saga of the threat that climate change poses to our earthly paradise is continued in another letter from Deon le Roux and in an article from William McClenney. Both contributions question the role of carbon dioxide as a cause of climate change, and are rather technical. However they highlight the dangers of thinking that the causes of climate change are easily understood.”

Ek wil lesers nie verveel met holrug-geryde argumente oor die aangeleentheid nie. William McClenney, “a California Licensed Professional Geologist and Registered Environmental Assessor” se artikel verskaf egter data wat minder algemeen bekend is en word hier in aflewerings geplaas.

Climate Change – The Short Story

In some ways, I applaud the sense of urgency that accompanies the perceived need to do something to affect climate change. The need is there in more ways than you presently know. But the means could be another matter entirely.

The Akkadian Empire under Sargon (2,300-2,200 BC), mankind’s first empire ever, succumbed to climate change that happened rather suddenly. A 300 year long period of drought struck this nascent civilization and toppled what turned out to be only a 100 year empire. The Old Kingdom of Egypt and the Harappans of the Indus Valley suffered a similar fate 4.200 years ago, succumbing to an abrupt drought that ended those civilizations, with Egyptians “forced to commit unheard of atrocities such as eating their own children and violating the sacred sancity of their own dead (Fekri Hassan, 2001)”.  The Mayans had pretty much the same luck with three periods of extreme drought at 810, 860 and 910 AD. Sadly just two years after the last drought, which saw 95% of the Mayan population gone, wet years returned to the Yucatan.

(to be continued)

Hit Parade: 29 Januarie 1966

26/01/2013 in Uncategorized

1. Get off my cloud – Rolling Stones (1)
2. The carnival is over – Seekers (2)
3. We can work it out – Beatles (5)
4. Hungry for love – Acads (3)
5. Wind me up – Cliff Richard (6)
6. Treat her right – Roy Head (7)
7. Yesterday-man – Chris Andrews (nuut)
8. California girls – Beach Boys (4)

Chris Andrews maak sy eerste verskyning op die hit parade, maar daar sal vorentoe weer van hom gehoor word. Sy stem was ietwat skerp vir my smaak, maar saam met die begeleiding was die effek nie onaardig nie.

Anna en ek sit soms tot laataand buite om die hemelruim met maan, planete en sterre, wolke en weerlig op die horison te bekyk, terwyl die aandlug geniet word. Vandag se liriek is deur wolke geinspireer. Ek onthou nie die komponis of musikant nie.

From both sides now

Bows and flows of angel hair
And ice-cream castles in the air
And feather canyons everywhere
I’ve looked at clouds that way
But now they only block the sun
They rain and snow on everyone
So many things I would have done
But clouds got in my way

I’ve looked at clouds from both sides now
From up and down and still somehow
It’s cloud illusions I recall
I really don’t know clouds at all

Moons and Junes and ferris wheels
The dizzy dancing way you feel
As every fairy tale comes real
I’ve looked at love that way
But now it’s just another show
You leave them laughing when you go
And if you care don’t let them know
Don’t give yourself away.

I’ve looked at love from both sides now

From give and take and still somehow

It’s love’s illusions I recall

I really don’t know love at all

Tears and fears and feeling proud
To say “I love you” right out loud
Every fairy tale comes real
I’ve looked at love that way
But now old friends are acting strange
They shake their heads, they say I’ve changed
But something’s lost and something’s gained
In living every day

I’ve looked at life from both sides now
From win and lose and still somehow
It’s life’s illusions I recall
I really don’t know life at all.

(die spasiering by die 2de koor-gedeelte is ‘n nuk van die rekenaar of blogformaat)

Hit Parade: 22 Januarie 1966

19/01/2013 in Uncategorized

1. Get off my cloud – Rolling Stones (2)
2. The carnival is over – Seekers (3)
3. Hungry for love – Acads (1)
4. California girls – Beach Boys (4)
5. We can work it out – Beatles (nuut)
6. Wind me up – Cliff Richard (8)
7. Treat her right – Roy Head (nuut)
8. How the mighty have fallen – Emile Dene (6)

Na 2 weke staan die Acads No.1 af aan die Stones, terwyl California girls, wat 7 weke op No.1 was, nou al vir die derde week aan die 4de plek vasklou. Die Beatles sluit aan by die Stones en Cliff met ‘n 7de hit in hierdie reeks.

Luister in jul geestesoor na Slim Whitman en sy Hawaiise ghitaar in “Remember me”:

When you’re sad and feeling blue
No one to tell your troubles to
Remember me, I’m the one who loves you.

When the world has turned you down
Not a true friend can be found
Remember me, I’m the one who loves you.

And through all kinds of weather
You’ll find I’ll never change
Through the sunshine and the shadow
I’ll always be the same

Well, together or alone
Where you go I’ll tag along
Remember me, I’m the one who loves you.

(herhaal vanaf “And through all kinds of weather….)

Hit Parade: 15 Januarie 1966

11/01/2013 in Uncategorized

1. Hungry for love – Acads (1)
2. Get off my cloud – Rolling Stones (3)
3. The carnival is over – Seekers (5)
4. California girls – Beach Boys (4)
5. Hang on Sloopy – Macoys (2)
6. How the mighty have fallen – Emile Dene (7)
7. Come back silly girl – Stuckatoes (6)
8. Wind me up – Cliff Richard (nuut)

Na ‘n afwesigheid van ses maande is Cliff weer terug op die Hit Parade met sy 7de hit sedert die begin van hierdie reeks en trek in daardie opsig gelyk met die Stones. Die Beatles en Elvis is een hit agter.

Cliff se liedjie is my liriek vir die week:

I’m just a little tin soldier in your arms
I’m good for nothing but to obey your commands
You never really love me, I know
So wind me up, let me go.

You don’t really need me
You’ve a hundred other toys
And teardrops don’t look good
In the eyes of soldier boys.

So pick me up and hold me one more time
There’s good consolation for this heart of mine
Whisper sweet words to the one who loves you so
Then wind me up, let me go.

Hit Parade: 8 Januarie 1966

05/01/2013 in Uncategorized

1. Hungry for love – Acads (2)
2. Hang on Sloopy – Macoys (3)
3. Get off my cloud – Rolling Stones (5)
4. California girls – Beach Boys (1)
5. The carnival is over – Seekers (6)
6. Come back silly girl – Stuckatoes (4)
7. How the mighty have fallen – Emile Dene (nuut)
8. Stand beside me – Perry Como (7)

Na ‘n rekord 7 weke in die eerste plek val ‘California girls’ ‘n rekord 3 plekke terug. Die hit parade was op plateverkope gebaseer en teen die tyd het al wat leef seker reeds die een aangeskaf.

Emile Dene het in April die vorige jaar die eerste plek gehaal met ‘Key to your heart’, maar nie hy of een van sy twee hits tot op datum lui by my ‘n klokkie nie. As liriek kry die Seekers se nuutste hierdie naweek ‘n kans:

Say goodbye my own true lover
As we sing a lover’s song
How it breaks my heart to leave you
Now the carnival is gone

High above the dawn is waking
And my tears are falling rain
For the carnival is over
We may never meet again

Like a drum my heart was beating
And your kiss was sweet as wine
But the joys of love are fleeting
For Pierrot and Columbine

Now the harbor light is calling
This will be our last goodbye
Though the carnival is over
I will love you till I die

Like a drum ……

I will .. love .. you .. till .. I .. die