Tuesday, 1 February 2011

Candlemas and palaeoecology

Major feasts start the evening before, so we've just sung the first Vespers of the Feast of the Presentation of Christ at the Temple, otherwise known as Candlemas. In the reading from Luke's gospel, Simeon calls Jesus "a light for revelation to the Gentiles and for glory to your people Israel." (Luke 2:32; NRSV), hence presumably the practice in the western church of blessing the candles for use in the church throughout the year, and the name 'Candlemas'.

Originally, the feast was a minor celebration. But in 541 AD, bubonic plague broke out in Constantinople, killing thousands. Emperor Justinian I, in consultation with the Patriarch of Constantinople, ordered a period of fasting and prayer throughout the Eastern Empire, culminating in processions and a prayer service asking for deliverance on Candlemas in 542, whereupon the plague ceased. In thanksgiving, Justinian elevated the feast to a more solemn celebration.

Sometime in my first couple of years at the Met Office, I went to a lecture on dendrochronology-palaeoecology. Dendrochronology is the scientific method of dating based on the analysis of patterns of tree-rings, which is then used to determine certain aspects of past ecologies. In areas where the climate is reasonably predictable, trees develop annual rings of different properties depending on weather, rain, temperature, soil acidity, plant nutrition, carbon dioxide concentration, and so on.

In 540 AD, there was a major eruption of the Rabaul caldera near Papua New Guinea, of roughly the same magnitude as Mount Pinatubo in 1991 or Krakatoa in 1883. These sort of events fling huge quantities of ash and sulphur dioxide into the atmosphere (Eyjafjallajökull in 2010 pales into insignificance), and appear in the palaeoecology record as ash strata in ice cores and the narrow tree rings resulting from global cooling. The lecturer was relating the science to all sorts of historical events and art, the really fascinating stuff you can get to in science, but only after paying your dues by painstaking counting of gazillions of tree-rings to assemble large enough datasets. He considered the global cooling following the 540 eruption as one of the contributions to the outbreak of plague; cooling would have affected grain crops, leading to famine, greater trade in grain, and hence in rats and fleas, and reduced resistance to disease.

By 542, the atmosphere was recovering, the sun returning and harvests improving. The lecturer didn't go as far as linking the return of the sun with Justinian's establishment of the feast celebrating the light for revelation to the nations - that was something I realised after the lecture. Probably there was no such link, but I liked the idea.


  1. Fascinating stuff Mx

  2. Hi Clare,
    I've finally got around to finding your blog and have spent my 1st class feast of Candlemas catching up with all your fine material :). Fascinating story of the ups and downs at Mucknell - your blog reminds me a lot of when Steward Community Woodland in Dartmoor started up in 2000 and they were blogging regularly. Hopefully eventually I'll be able to blog more openly about life at Freeland, but for the time being there's just a once-a-month photo blog for a little insight: http://oscfreeland.wordpress.com/blog/
    I look forward to being able to visit you all someday - someone needs to arrange a novitiate study day there!
    Much love from one of those annoying type 9s,

  3. Also, these woodchip boilers seem to be a perpetual nightmare. When I was living down at Bedzed in South London, we had a 'prototype' woodchip boiler to run the whole estate hot water/heating system and it broke down so often we switched permanently to the 3 mains gas boilers. Similarly the grey water recycling system broke down and so the landlords helpfully reconnected us to the mains sewage. So much for eco-living. Maybe they've got it all sorted out by now - haven't been back since 2005. Eco-tech often seems to leave us worse off than when we started. Flexibility and simple-tech redundant systems are key imo! It always frustrates me that when the electricity grid goes down, all those shiny pv panels go to sleep as well. Surely can't be that hard to add the option to go 'off grid' when necessary? Anyway, rant over.

  4. T, thanks for comments. You didn't say you lived in Zedbed - interesting experience given that it's held up as being an exemplar. Like the 'little insight' of your blog, including photo of the compost tidal wave about to inundate the postulant! Now switch off the computer!
    (PS. Have no idea whether Blogger will now email you to say that someone else has commented on this post, so you may never see this. Oh well. How can I find out your email address?)