I recently came across Azimuth – a fascinating blog by John Baez.
What prompted me to actually get around to writing a brief article was the latest article – This Week’s Finds (Week 307) – about El Nino and its uncertain causes and comes with great graphics and interesting explanations.
A brief extract:
I finally broke that mental block when I read some stuff on William Kessler‘s website. He’s an expert on the El Niño phenomenon who works at the Pacific Marine Environmental Laboratory. One thing I like about his explanations is that he says what we do know about the El Niño, and also what we don’t know. We don’t know what triggers it!
In fact, Kessler says the El Niño would make a great research topic for a smart young scientist. In an email to me, which he has allowed me to quote, he said:
We understand lots of details but the big picture remains mysterious. And I enjoyed your interview with Tim Palmer because it brought out a lot of the sources of uncertainty in present-generation climate modeling. However, with El Niño, the mystery is beyond Tim’s discussion of the difficulties of climate modeling. We do not know whether the tropical climate system on El Niño timescales is stable (in which case El Niño needs an external trigger, of which there are many candidates) or unstable. In the 80s and 90s we developed simple “toy” models that convinced the community that the system was unstable and El Niño could be expected to arise naturally within the tropical climate system. Now that is in doubt, and we are faced with a fundamental uncertainty about the very nature of the beast. Since none of us old farts has any new ideas (I just came back from a conference that reviewed this stuff), this is a fruitful field for a smart young person.
So, I hope some smart young person reads this and dives into working on El Niño!
The first time I came across Azimuth was only Oct 15th – This Week’s Finds (Week 304) – a discussion about the Younger Dryas, which starts:
About 10,800 BC, something dramatic happened.
The last glacial period seemed to be ending quite nicely, things had warmed up a lot — but then, suddenly, the temperature in Europe dropped about 7 °C! In Greenland, it dropped about twice that much. In England it got so cold that glaciers started forming! In the Netherlands, in winter, temperatures regularly fell below -20 °C. Throughout much of Europe trees retreated, replaced by alpine landscapes, and tundra. The climate was affected as far as Syria, where drought punished the ancient settlement of Abu Hurerya. But it doesn’t seem to have been a world-wide event.
This cold spell lasted for about 1300 years. And then, just as suddenly as it began, it ended! Around 9,500 BC, the temperature in Europe bounced back.
This episode is called the Younger Dryas, after a certain wildflower that enjoys cold weather, whose pollen is common in this period.
What caused the Younger Dryas? Could it happen again? An event like this could wreak havoc, so it’s important to know. Alas, as so often in science, the answer to these questions is “we’re not sure, but….”
I’m sure everyone who is fascinated by climate science will benefit from reading Azimuth.
The Science of Doom 
Hey, thanks for pointing out that site. I hadn’t seen it before.
Thank you so much.
The Baez piece is a marvel of thinking,
writing, and imagination. It was a
pleasure to read and it provided me
with many spring boards to other lines
of thought and inquiry.
I very much appreciate the way that you
have GW and AGW in larger contexts than
the subjects often are given.
It’s a little misleading to say that Younger Dryas was not a world wide event. It was preceded by the Bolling-Allerod Warm Interval which in turn could have been triggered by melt water pulse 1A which also may have triggered the Antarctic Cold Reversal.
Click to access weaveretal.-science-2003.pdf
A more recent paper on the same subject with a different mechanism:
Click to access Liu-2009-Science.pdf
Both invoke the global see-saw effect where when one hemisphere warms, the other cools.
Also very interesting to read is the discussion with Tim Palmer about uncertainty in climate prediction.
I’d like to write about climate uncertainty but I don’t think I understand it.
“I’d like to write about climate uncertainty but I don’t think I understand it.”
Very Good!
Me too!
I can’t even derstand certainty.
Can’t cite the link, but recall that articles c. 2005 identified the 1,500-year Younger Dryas “cold shock” as due to a series of astronomical impacts rather a climatological or meteorological event. Apparently a passing deep-space object disrupted the solar system’s encompassing Oort Cloud (qv), sending a rain of exo-debris cascading into inner planets’ orbital vicinities.
Had Earth’s budding Holocene Interglacial Epoch not suffered this setback, our median 12,250-year remission from recurrent Pleistocene Ice Time would likely have ended c. AD 450, coincident with the Fall of Rome. As it is, reinforcing cyclical factors during a rebound from the 500-year Little Ice Age (LIA) that began c. AD 1325 – ’75 presage not merely a 40-year Dalton or a 70-year Maunder Minimum but a resurgence to full-blown glaciation due to last approximately 102,000 years.
Academic climatologists (sic) who willfully fail to recognize this pattern, which has persisted some 2.6-million years throughout the Pleistocene Era, do humanity a grave disservice. Whether Deep Cold seizes on us in this 21st Century or –with luck– some generations later, the fact remains that industrial/technological civilization exists on borrowed time. As Luddite sociopaths, AGW catastrophists anticipate humanity’s pending die-off with approval, failing to realize they will be the first to go.
I really would like to read that paper. Y-D is nothing special http://virakkraft.com/greenland_curves.html
Very refreshing to read about the state of uncertainty around El Nino/la Nina causes and triggers. Especially since the strong linkage between ENSO and global climate; 1998, 2005 and now 2010 all being “warm” and associated with a strong ENSO, followed by La Nina cooling. I would recommend long sleeves for 2011. Personally I like it warmer..