Saturday, July 27, 2013

Pillar of Salt

by Joan Cope Savage

View of pillars in the salt mine under the city of Detroit.
Biblically speaking -  given a chance to escape disaster, Lot's wife was told to flee without a backward look. Yet, she turned. We don't know if, in a flash, she saw Sodom consumed by sulfurous fire or if she died in the process of turning.  As the story has it, the backward look turned her into a pillar of salt.

Her fate reminds me of the shadows of people burnt into the walls of Hiroshima by the force of nuclear explosion or the hollow casts of Pompeiian citizens shaped in volcanic ash. We know about them through the patterns they left behind when disaster struck, disaster they did not escape.

How many among us are not 'bad' people, but like Lot's wife, we are hesitate to flee the familiar?
I might be one.

We -or I- could turn into a modern version of the pillar of salt, looking backward, even briefly.

I strive to move even a little bit, acknowledging my uncertain future.   Like those trapped in time before me, I might not be moving fast enough. I'd rather be found face-forward, at least.

Saturday, July 20, 2013

note to self about science fiction

By Joan Savage

Allegedly, a Cold War solution to the risk of nuclear war (another abrupt event to consider, to be sure) was to move the core personnel of government to an undisclosed location in the Appalachians. That approach was without thinking through the logistics of finding and moving people within the twenty minutes’ warning window for incoming missiles.
A rush of meltwater from the Antarctic or Greenland might have weeks, months, or years to work its way to DC, but its disruption of climate along the way would be just as spectacular. Who needs science fiction.

Cross posted as a comment on a Climate Progress article that I recommend, Like Butter: Study Explains Surprising Acceleration of Greenland's Inland Ice.

Wednesday, July 10, 2013

The poop on worm poop as a paleotemperature marker, corrected and updated

by Joan Savage

Why are researchers about paleoclimate so interested in earthworms, or actually in one kind of earthworm?

The common nightcrawler earthworm, Lumbricus terrestris, produces castings year round that include calcium carbonate granules. Not exciting you might think, and even with a vivid imagination,  no, no, earthworm farming is not the latest foolish idea for carbon dioxide sequestration.

Photo of Lumbricus terrestris from wikipedia commons

The calcium-carbonate-flecked worm poop was among those curiosities of nature known to few, and among the few were several scientists collaborating in the UK,  one group is Emma A.A. Versteegh, Stuart Black  Matthew G. Canti  Mark E. Hodson.
Their article Earthworm-produced calcite granules: a new terrestrial palaeothermometer? is fortunately Open Access. What they  produced is a newprocedure for tracking LOCAL temperature conditions over thousands of years in many areas of the planet. This method uses  δ18O values, as determined on individual calcite granules. As they say, "As the granules are abundant in modern soils, buried soils and archaeological contexts, and can be dated using U-Th disequilibria, the developed palaeotemperature relationship has enormous potential for application to Holocene and Pleistocene time intervals."
The correlation to  δ18O data by Kim & O'Neil was at p < 0.0005

In the world of science, particularly climate science, that's a rock star. 

The more recent of the two article's authors are Loredana Brinza, Paul D. Quinn, Paul F. Schofield,  J. Frederick W. Mosselmans, and Mark E. Hodson.  The Brinza et al article published earlier this week in Geochimica et Cosmochimica Acta, "Incorporation of strontium in earthworm-secreted calcium carbonate granules produced in strontium-amended and strontium-bearing soil," was treated like a rock star, possibly because it was confused with the previous article's bolder stance. The title and abstract modestly didn't hint at the implication of their work.
The full article is available for free for what you can read in five minutes! The full article is 17 pages including references. I raced to the conclusions which were both optimistic about the eventual use as a paleoproxy, yet they cautioned that more research is needed on soil conditions and temperature. What had been a variable in the study was the amount of strontium in the soil.
Basically, here's how the Sr/Ca works. The ratio of strontium to calcium in calcium carbonate formation is affected by temperature, but strontium90 presence has also been used to monitor nuclear fallout.  The Sr/Ca ratio has been tracked in coral reefs, over 10^5 years to within 0.5 degrees C accuracy when tested against oxygen isotope records.  That's over 100,000 years, count those zeroes.  So, the earthworms' casting granules with their distinct Sr/Ca ratios are miniature temperature records for the time that they pooped, but soils are not the watery solutions from which corals took their minerals.  

Keep both the bold Versteegh and the cautious Brinza articles in mind.  One's ready to roll and the other might prove useful, too.

Where has the nightcrawler been in the Holocene and Pleistocene? 

In the now-rare definitive work by John W. Reynolds, The Earthworms  (Lubricidae and Sparganophilidae) of Ontario,  Reynolds cites Gates (1972).  Lumbricus terrestris Linnaeus 1758 is a native of Palearctis, now known as Europe, Iceland, North America, South America, Siberia, South Africa, and Australasia.

Reynolds also comments on a belief that the worms had been introduced to North America from Europe, which he corrects to say the worms were native south of the last continental glaciation.  That does suggest that eager researchers may be limited to recently re-introduced post-Pleistocene worm castings in forests of Wisconsin, upper New York, Canada, and other areas that were glaciated up to about 11K years ago.

Palearctis leaves out North Africa and Antarctica. Australasia doesn't include mainland Asia, the subcontinent of India or the Middle East, either.

Even so,  what an opportunity to pinpoint temperature conditions at archaeological sites that have been dated by carbon isotopes, or in soils or geologic strata!   It's not just for coral and mussels anymore.

I am grateful to BBC news for correctly reporting that the Versteegh et al article was the breakthrough.

TB and geoengineering responses to climate change

Joe Romm recently posted on research that further discredits the geoengineering proposal to seed the world's oceans with iron. The iron seeders think that an algae bloom would store CO2 in ocean sediments, but Joe points to studies  that show the effects would be flawed and or short-lived.

My comment was so much fun to write that I've copied it here:

The iron-sprinkling notion reminds me of the 19th century belief that wearing garlic around one’s neck would ward off tuberculosis.
Because TB takes time to become fully symptomatic, the garlic wearers refused to believe they were making a mistake until it was too late. That surely sounds like the current inadequate measures to reduce symptomatic climate change.
The iron sprinkling and the garlic are also somewhat similar in terms of dose and effect.
Garlic extract can kill Mycobacterium tuberculosum, at least in a Petri dish, but it’s not proven that eating a huge amount constantly is possible at therapeutic doses. Similarly, the iron sprinkling has the now-identified bad side effects and is not possible at a therapeutic dose.
To wrap the analogy, TB levels go down when preconditions for communicability are reduced. Even today with cures available, prevention is a better epidemiological approach than trying to treat millions of cases.
Same goes for climate impacts.
Being hopelessly addicted to puns, I must say that it felt good to get that off my chest.