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Unforced Variations: Jan 2014

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First open thread of the new year. A time for ‘best of’s of climate science last year and previews for the this year perhaps? We will have an assessment of the updates to annual indices and model/data comparisons later in the month.

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662 Responses to "Unforced Variations: Jan 2014"

  1. @635, 647,650–wili, Tony Weddle; prokaryotes:

    The greatest human genetic diversity found anywhere is found among the San, going by markers which descend on the y-chromosome.

    Cognitively, linguistically, and technically their culture marks a key moment in the global footprint of the human race.

    Here’s a video with Spencer Wells–equal parts geneticist and historian. The link plays the 13-part video in sequence–plus thumb-nail menu. Wells meets with a group of the San in part two. If you haven’t seen it:

    http://www.youtube.com/watch?v=nBJDGzzrMyQ&list=PL895E779F2D722DAF&index=1

    The first main part of the human migration could not have happened as it did without the lower sea levels of an ice age. The window of opportunity for getting this story straight is particular to now, as Wells says near the end. I think it’s a key to a clear-eyed view of what time it is now. For diverse reasons.

  2. DIOGENES “With the Abbott government, did you expect different?”

    I did not expect the Australian government to screw with the Barrier Reef.

  3. 30 January 2014
    Tropical cyclone frequency new STUDY Published
    Australian tropical cyclone activity lower than at any time over the past 550–1,500 years by Jordahna Haig, Jonathan Nott & Gert-Jan Reichart http://www.nature.com/nature/journal/v505/n7485/full/nature12882.html

    Our study shows that current seasonal cyclone activity is at its lowest level in Western Australia since 500 AD and since about 1400 AD in Queensland. That decline began about 40 years ago.

    While Australia’s official cyclone records only date back to 1906, we can track cyclones further back in time using measurements of isotopes housed within limestone cave stalagmites. Those stalagmites grow upwards from the cave floor as rainwater containing dissolved limestone drips from the cave ceiling.

    The isotope chemistry of tropical cyclone rainwater differs from that of monsoonal and thunderstorm rainwater. As a consequence, it is possible to analyse the chemistry of each of the stalagmite layers, which are approximately 1/10th of a millimetre thick, and generate a record of cyclones over the past 1500 to 2000 years.

    […] Global trends – Several recent studies published in leading journals – including these papers involving the Australian Bureau of Meteorology, Columbia University, and the Massachusetts Institute of Technology – have all separately projected the frequency of tropical cyclones will decrease in the Australian region due to global climate change.

    But while the number of cyclones is expected to decrease, the intensity of those cyclones that do occur is expected to increase.

    Those previous studies have suggested we would see those changes occur towards the middle to the end of the 21st century. However, our new study suggests this decline in cyclone frequency is ALREADY OCCURRING !!!!

    We cannot be sure that this current decrease in cyclone activity is due to climate change – but it is mirroring the forecasts.

    […] Essentially, we are faced with a choice. Continue to hope and plan for the best, as if this current 40-year lull will continue. Or hope for the best, but prepare for the worst.

    […] government’s recent decision to remove a safeguard in state planning policy to consider future sea level rise (which could worsen storm surges in a cyclone).

    The conservative approach that I believe is worth taking, based on our research and that of others, appears to be the opposite of what is now happening. https://theconversation.com/tropical-cyclone-frequency-falls-to-centuries-low-in-australia-but-will-the-lull-last-20814

  4. > our new study suggests this decline in
    > cyclone frequency is ALREADY OCCURRING !!!!

    Wait, is that a direct quote?
    Or are you one of the authors?
    “our new study” would be words written by the scientists

    Are you making that up? The abstract you link to says:

    Our results reveal a repeated multicentennial cycle of tropical cyclone activity, the most recent of which commenced around ad 1700. The present cycle includes a sharp decrease in activity after 1960 in Western Australia…. Our results, although based on a limited record, suggest that this may be occurring much earlier than expected.

    Did you get the words you posted above from some secondary source, or a press release? Please cite your source if so.

    Please don’t make up scary stuff and attribute it to scientists.
    Reality is more than scary enough.

  6. And here’s the source, plenty scary without the “!!!”

    29 January 2014, 7.49pm GMT
    Tropical cyclone frequency falls to centuries-low in Australia – but will the lull last?

    … Those previous studies have suggested we would see those changes occur towards the middle to the end of the 21st century. However, our new study suggests this decline in cyclone frequency is already occurring.

    We cannot be sure that this current decrease in cyclone activity is due to climate change – but it is mirroring the forecasts.

    Our results also confirm the conclusions of other studies into long-term cyclone behaviour, which show that the past 40 to 100 years of cyclone activity in Australia has been very low compared to times previous.

    Planning based on a lull in the storm

    The results of our study suggest that we may have a problem with coastal development in cyclone-prone regions, particularly in built-up parts of Queensland.

    For many years, Western Australia had a more cautious approach on where coastal development was allowed …. However, this policy has now changed and is now more in line with Queensland coastal policy…. based on the history of cyclones over the last 40 years, and 100 years at best.

    This period is unrepresentative of the natural variability of cyclones. So relying on this narrow window of time means that we are making risky assumptions ….

    Author
    Jonathan Nott
    Professor of Physical Geography at James Cook University

    There’s an interesting parallel to California’s experience, where all the expectations appear now to have been based on a couple of very wet centuries in an otherwise very much drier climate than the Spaniards found here when they arrived and we’ve built our assumptions on that.

    Not to mention the larger time span, the stretch of Holocene years that were sufficiently calm to allow development of agriculture and cities rather than migratory hunting camps.

    This might be a whole new take on what the habitable zone and habitable planets are like — perhaps our experience of the Universe really has been peculiarly uncommonly favorable.

    Have we just been very lucky?

  7. 17 January 2014
    “Large, older trees have been found to grow faster and absorb carbon dioxide MORE RAPIDLY than younger, smaller trees, despite the PREVIOUS VIEW that trees’ growth slowed as they developed.

    “Research published in the journal Nature this week shows that in 97% of tropical and temperate tree species, growth rate increases with size. This suggests that older trees play a VITAL ROLE in ABSORBING carbon dioxide from the atmosphere.”

    https://theconversation.com/big-old-trees-grow-faster-making-them-vital-carbon-absorbers-22104

    Rate of tree carbon accumulation increases continuously with tree size!
    N. L. Stephenson et al
    http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12914.html

    So, there you have it guys. Size does matter!

    Walter

  8. Fair enough, wili. Tainter talks of complex societies, which I guess I’ve been thinking of as societies, having institutions. As the kinds of societies we have today are complex, I don’t think they can become sustainable (which, to my mind, doesn’t include the notion of time).