Hi Jennifer,
An interesting news article appeared in Sci-Tech-Today on November 17, 2006 entitled 'Iceberg Spotted from New Zealand Shore'. The article reads in part:
"An iceberg has been spotted from the New Zealand shore for the first time in 75 years, one of about 100 that have been drifting south of the country.
The giant ice chunk was visible Thursday from Dunedin on South Island but has since moved away, driven by winds and ocean currents. The flotilla of icebergs - some as big as houses - were first spotted south of New Zealand early this month.
Last year, icebergs were seen in the country's waters for the first time in 56 years. But the last time one was visible from the New Zealand shore was June 1931, said Mike Williams, an oceanographer at the National Institute of Water & Atmospheric Research.
Scientists have been reluctant to blame global warming.
"We've been monitoring these things for such a short time, it's impossible to see. To say this is unusual and related to global warming is just not possible," Paul Augustinus, an Auckland University glacial geomorphology lecturer, told the New Zealand Herald earlier this month."
This observation is interesting in light of the below average sea surface temperatures that are currently observed in the Southern Hemisphere high latitudes. In the November 17 2006 analysis, the cold anomalies extend north to the South Island of New Zealand.
The news article makes the standard comment on whether or not this event is related to global warming. The more appropriate climate science question, however, is whether the geographic distribution of icebergs in both hemispheres have changed over the last several decades, and, if so, why?
In the case of this event, could colder than average ocean conditions in this region be part of the explanation?
Regards,
Paul Biggs
Ian, I glad you have overturned the laws of therodynamics.
Therodynamics says that work! (wind, currrents) actually must increase as temperature gradients increase. But due to differential warming (for whatever cause) the polar regions are warming more than equitorial regions, this should reduce the temperature gradient and hence reduce energy transport by wind & currents.
Agree on low revelles at equatorial zones but this is balanced by movement of surface water from tropics to temperate zones where mixing zones are deeper. The modelled future CO2 uptakes do not account for the changed weighting of these elements.
Nor do they appear to include any responses of nature to these new levels other than increased temperature. An increased speed of ocean cycling and an increased speed of atmospheric cycling would seem to be the most obvious responses.
And these, given the existing range of natural variation in these phenomena, are quite capable of impacting on the outcomes of the modelling.
And before someone wants me to mortgage the house to the hilt to fix this "problem" it is the least they can do to supply detail on the sensitivity of modelled outcomes to these other, entirely plausible, and highly probable outcomes.
That, at its core, is the problem. The GW proponents are fundamentally pessimistic. And that means the glass is always half empty and getting worse. Minds like yours have been clinically proven to have reduced capacity to assess or even identify mitigating or positive variables. The same can also be said in respect of optimists capacity to recognise adverse or negative variables.
That is why we have debates and that is also why there are few things more dangerous than a bunch of pessimists telling the world that the debate is over when it clearly is not and claiming that any sceptics are either nutters or paid hacks.
bushfires - not relevant to the issue. We're talking about the fate of the fossil fuel CO2 - which has a fingerprint - where have all the emissions ended up? They're not all in the atmosphere. The ocean is a big sink.
The Revelle effect is the buffer capacity. Not just a North Atlantic issue. Low Revelle factors in warm tropical and sub-tropical - high factors nin cold water high latitudes. CO2 uptake inversely proportional to the Revlle factor. Hence lower the factor the more equilibrium concentrations in the surface can be for a given level of atmospheric CO2. i.e. CO2 effect more in tropics.
Again reefs themselves have their own special localised factors.
A big difficulty in our discussion is about four issues - absolute point samples, rates, flux balances and integration. You have to think what you're arguing. Then you have to decide what happens in what time frame, what spatial dimension geographically, and what vertical dimension and with currents, complicated by the fixing of mixing. So after 200 years it ain't gone too far and atmospheric CO2 is still increasing.
Think again about the issue of "a base line". It's has measured the "fingerprint" of industrial activity since 1800s - the CO2 from the fossil fuels in the ocean can be identfied from isotopic tracer techniques - it is not uniformly distributed - see above discussions. So it's a base line OK - BUT also an INTEGRATION of 200 years of fossil fuel CO2 sloshing around the system.
I'm not an Al Gore fan. His movie can simply be assessed on a right/not right/maybe checklist. He doesn't do too badly. 100% better than opposition efforts. Methods and politics though are another issue. He's probably on balance a divisive character.
Interesting, Luke. So tell me, how does the delta carbon method distinguish between CO2 from a bushfire (deemed non-anthropogenic under IPCC) and CO2 from a wood fired stove (which is)?
And I am seriously pondering how anyone could assume that they know the current location of a body of water in a series of surface and sub-ocean currents that absorbed CO2 from the trees cleared by convicts at Botany Bay? And am also pondering how your experts can distinguish that CO2 from the fires lit by blackfellas all over the rest of the country?
And I still ponder how you can use localised, specifically North Atlantic problems of Revelle effect to conclude that we have a Global problem?
You have toned down your language but you are still expecting me to make a leap of faith. I accept that there MAY be a probability of a problem developing but given the disparity in absorbed CO2 levels from ocean to ocean and within oceans and within strata and columns, then there are sufficient grounds for simply saying, "yet to be established".
Uncertainty is always the only certainty.
As for your 95 cruises and three large transects, etc, thats fine, but we really need to trace some emissions right through the "system" over time like a barium meal. All this static point data is nothing more than a base line.
And even if we do get to a point where localised ocean volumes can no longer absorb CO2 then we will then need to see how the wind will intervene in a changed local airmass.
Your cause is also not helped by the fact that there is a continual supply of people like Al Gore who's slimy deceptive body language and communications "techniques" tweak every single button of an experienced, and once well paid, liar detector like me.
And I invite every other reader of this trail to go back over it to see who was escallating the invective.
Now Ian - you have the least to complain about insults as insults are your tool of trade. I'm not insulting you - this is simply a robust discussion in your preferred style.
Ian - you ought be rattled enough to want to chase it down. But you're not. That says heaps.
I'm not claiming certainty - you are ! You are certain that you are 100% right.
And your standard approach is to put shit on the scientific community as a quick draw response and belittle the argument. Of course this isn't a scholarly journal - it's a blog so we can amuse the spectators (if more then 2 are still with us) and call each other dickheads.
Most of these articles conclude with "more work to be done". But jeepers - are these problems simple. They're grand challenge.
You are confusing an equilibrium position with a transitional problem.
The data are from 95 cruises and some 9518 hydrographic stations over the 1990s. It was conducted in 3 north south transects in the Atlantic, Pacific and Indian Oceans. It represents the most accurate and comprehensive view of global ocean inorganic carbon distribution available.
The delta carbon tracer method was used to separate the anthropogenic CO2 component from the measured dissolved inorganic carbon concentrations. So the data sets might be short term but they INTEGRATE the location of the anthropogenic CO2 emitted since the beginning of the industrial revolution in the 18th century.
PONDER THAT !
5 years of data preparation since 1998 before analysis.
As you would expect the most vertically integrated concentrations are in the North Atlantic. By contrast the Southern Ocean south of 50S has very little integrated anthropogenic CO2 concentrations. Becuase anthropogenic CO2 invades the ocean by gas exchange across the air-sea interface, the highest concentrations of CO2 are found in the near-surface waters. The global atmospheric CO2 is increasing as a steady rate from burning of fossil fuels.
The bit you have not pondered is at what speed the carbonate ion concentration will decreasse - the Revelle factor increases and the ability to absorb more CO2 decreases. So the long term view is that maybe the capacity of the ocean to act as a CO2 sink is compromised. More CO2 in the atmosphere eequals more warming - think upper end climate scenarios more likely.
The authors conclude that the mixing and stratification issues are complex, the export production and calcification rates of the ocean are not well enough known.
One can easily get a scenario wherein the short term transition we damage reefs and southern ocean food chain then in the longer term reduce the capacity of the ocean to be a sink.
So don't think equilibrium - think transition. What happens at what levels in what time frame. That's why you'd have to model it.
And of course locally our terrestrial silicate export in the oceans, a component of local ocean alkalinity has decreased markedly. Unknown implications but apparently now getting fertiliser like responses to sugar cane from silicate application. Probably a rounding error in the scheme of things - but globally - I don't know. Has been raised.
So does all this mean a case for alarm. Maybe not. But certainly enough for "concern" if you're interested in politics and the environment as to be here in this place. Dismissing out of hand - which is your CERTAINTY indicates a closing off of thought processes - development of a growing barrier of cognitive dissonance among industry advocates such as yourself just when we need some attentive buy-in to keep moving the science. I urge you to consider your responsibilities as both an advocate for producer land rights and a person of influence in the environmental debate.