Do you know of any references where ordinary sea water has been titrated with CO2 and the pH measured?

Should you write such an article, might you please be quite specific about how a qualitative observation (heavy oxygen isotopes are disproportionately left behind during evaporation) becomes a quantitative equation linking delta-O with temperature? If you do a frequency plot of a large number of diverse isotope ratios used in climatology, is the median displaced from the reference standard? It seems to me that there are many more reported isotope ratios attributed to heating than to cooling. Have you found limits to the amount of differentiation that can happen in nature? Overall, is the distribution centered, skewed and/or bounded?

In addition, there’s a plethora of data on current ocean acidification.

http://blog.scienceinsociety.northwestern.edu/2009/06/why-michele-bachmann-should-watch-apollo-13/

But clearly this guy’s idea of CO2 “pollution” is so far off base as to be laughable.

I’m looking forward to your future essays on paleoclimatology.

I don’t have better reconstruction of sea level for the more recent periods.

The sea level spreadsheet does have a link to an NCDC archive of sea levels that goes back 9,000 years or so for many locations around the world. It is not in an easy to use format (would probably take a long time to turn it into something useful).

It is interesting though to see how much sea level change has varied by location over the recent past. For example, James Bay Canada has seen sea level fall by a huge 250 metres over the past 7,000 years (due to post-glacial rebound) while the Thames river area has seen sea level rise by 16 metres over the same period (due to post-glacial rebound of Scotland which has tilted southern England downward). These are the two extremes I believe.

Now you see the problem with simply picking a few sea level gauges for an estimate (one might need all of them).

ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleocean/relative_sea_level/sealevel.dat

What are some of the better sea level reconstructions over the last 2,000 years?

I’d like to compare Jerejeva to the period from the Roman Warming through the Little Ice Age.

Scale is a “funny thing”. I appended Jerejeva onto the last 150,000 years of Miller… 1700-2003 was a dot on the graph. ;)

Global Sea Level Reconstruction since 1700

Looks like a good study. I’ve said before that you need as many sea level datasites as possible to carry out a decent review of sea level since there is so much post-glacial rebound, local land uplift/subsidence and even plate tectonics to take into account.

I’ll put it in but I should note that I am just focussing on the PaleoClimate starting about 10,000 years ago. There are lots of people looking at the more recent temperature trends and there is lots of easily available data so there is not as much rationale for earlier periods.

Joel Shore (09:53:41) :

[...]

The issue isn’t one of absolute CO2 levels but rather how fast CO2 levels are changing relative to the rate at which CaCO3 can be dissolved from rocks to neutralize the acidification.

That’s not entirely accurate. The Carbonate Compensation Depth (or Lysocline) is the depth at which carbonate shells dissolve faster than they accumulate. That depth is primarily determined by several factors…

-Water temperature
-Depth (pressure)
-CO2 concentration
-pH (high pH values aid in carbonate preservation)
-Amount of carbonate sediment supply
-Amount of terrigenous sediment supply

Calcium carbonate solubility increases with increasing carbon dioxide content, lower temperatures, and increasing pressure.

SOURCE

There is solid evidence that the Lysocline “shoaled” or became shallower for a brief period of time during the Paleocene-Eocene Thermal Maximum. Several cores obtained from the Walvis Ridge area in the South Atlantic during Ocean Drilling Program (ODP) Leg 208 contained a layer of red clay at the P-E boundary in the middle of an extensive carbonate ooze section (Zachos et al., 2005). This certainly indicates a disruption of the lysocline during the PETM; but it doesn’t prove that it was ocean acidification.

The PETM was a period of extensive submarine volcanic activity (Storey et al. 2007) and pedogenic carbonate reconstructions do support the possibility that methane hydrates released by that volcanic activity may have sharply increased oceanic CO2 concentrations.

But… The terrigenous paleobotanical evidence does not support elevated atmospheric CO2 levels during the PETM (Royer et al., 2001). The SI data indicate CO2 levels in North America to have been between 300 and 400 ppmv during the PETM.

So, the PETM may have been an example of ocean acdification… But there is NO evidence that it was caused by a sharp increase in atmospheric CO2 levels.

On top of that… There is solid evidence that elevated atmospheric CO2 levels have actually caused carbonate deposition to increase over the last 220 years (Iglesias-Rodriguez et al., 2008)… And when sudden increases of atmospheric CO2 have been tested under laboratory conditions, “otoliths (aragonite ear bones) of young fish grown under high CO2 (low pH) conditions are larger than normal, contrary to expectation” (Checkley et al., 2009).

There is no evidence to support the notion that rising atmospheric CO2 levels have ever caused ocean acidification… And the hypothesis has been falsified under empirical conditions.

“The issue isn’t one of absolute CO2 levels but rather how fast CO2 levels are changing relative to the rate at which CaCO3 can be dissolved from rocks to neutralize the acidification.”

It used to be: “CO2 will cause runaway globaloney! Everybody panic!!”

But the planet laughed at their presumption, and cooled as CO2 rose.

So now they re-frame the argument, just like Joel Shore does above. Forget the fact that the biosphere expands when more plant food is available. Only rocks matter now.

And they wonder why we laugh at their nonsense.

The ocean acidification argument is so over-played.

The Cambrian explosion of (marine) life occured when CO2 was 7,000 ppm. Corals evolved when CO2 was 20 times higher than today. Carbonate-shell based organisms like Trilobites and Ammonites (as big as 8 feet across) dominated the world’s oceans when CO2 was 20 times higher than today.

The issue isn’t one of absolute CO2 levels but rather how fast CO2 levels are changing relative to the rate at which CaCO3 can be dissolved from rocks to neutralize the acidification.

The greenhouse effect is 33C. 11 halvings of CO2 puts CO2 level at effectively Zero – so even mathematically, it cannot be higher than 3.0C per doubling.

This isn’t really true. For one thing, there is no reason to believe that the rise per doubling is constant over so large a range. Also, that 33C number is with our current albedo…A “snowball earth” could be more than 33C colder. Hopefully, the climate sensitivity isn’t any higher than 3 C per doubling but I don’t think there are any mathematical guarantees that this is so.

You might want to incorporate Jevrejeva et al., (2006) into your paleo sea level series…

Global Sea Level Reconstruction since 1700

re ocean acidification.

I can find no paper where CO2 has been titrated into actual ocean water to measure the pH change. All I can find is models.

Can anyone point to a reference?