Author: Jeremy Cherfas

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I got your temperature anomaly right here

Luigi pointed out that my latching onto that animation of the heat wave sweeping across America “only tells you that it’s hot. Not that it’s any hotter than in ought to be”. And, as so often, he’s right. He was good enough to link to items that demonstrated that both May and June were indeed hotter than they ought to be. In the interests of making things as easy as possible, I’m going to share a picture of not the temperature but the temperature anomaly. And boy, has it been hotter than it ought to have been.

Asos jun2011 nocities

8 degrees F is almost 4.5 degrees C.

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Climate change: thanks for all the dead fish

One of the little-appreciated aspects of climate change is that greater variability brings with it more frequent extremes, and if a system is already stressed it doesn’t take much to tip it over the edge. In many places, aquaculture is such a system. The photo ((By Edd Gumban of The Philippine Star.)) is from November 2010, but a glance at the news shows that massive fishkills are a common feature, and not just in The Philippines.

What seems to happen is a series of “unlucky” breaks. The fish are already densely stocked and overfed, and in the morning oxygen levels in the water can be dangerously low because the plants don’t produce oxygen in the dark. Most days, that’s alright, because the algae and plants in the water start to photosynthesise and put out oxygen. A cloudy morning, however, can reduce photosynthesis, and if the day is also hot oxygen levels fall even further as dissolved oxygen escapes. Worse, in hotter water the metabolism of the fish revs up, so they need more oxygen. Throw in a rainstorm, especially if soils around the fish farms are bare, and you get an influx of turbid water that further blocks photosynthesis, dropping oxygen lower still. Tonnes of fish suffocate. And lakes may take years to recover.

Authorities recommend “premature harvest” but that is clearly a Band-aid. The sustainable solution is to make the system more resilient, by decreasing stocking levels and feeding, and trying to ensure that rainwater inflows do not carry too much sediment into the water. Fish farmers cannot control the weather; can they adapt to extremes that can certainly control their business?

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Genetic erosion gets worse

We get hours of amusement from poking holes in the many ways in which statements about the loss of 75% of agricultural biodiversity are likely to be less than accurate any way you slice them. But here’s an entirely new wrinkle. A friend recently wrote asking for some moral support for a grant proposal, which included a forceful justificatory phrase to the effect that 75% of agricultural diversity has been lost since 1990. ((My emphasis, as the posh editors say.))

I twitted him gently about this, something snitty to the effect of “interesting statistic, have you got a source for that?” And blow me down if he didn’t. Not just any old source either. A communication from the [European] Commission to the European Parliament, the Council, the Economic and Social Committee and the Committee of the Regions, no less, entitled Our life insurance, our natural capital: an EU biodiversity strategy to 2020, aka COM(2011) 244 final.

And there it is, on page 1 of the Introduction.

[A]ccording to the FAO … 75% of the genetic diversity of agricultural crops has been lost worldwide since 1990.

I wonder where they got that figure? Not from FAO. The same year is present in at least one other language, so if it is a typo it entered the proceedings early. But honestly, did nobody find it just the least little bit odd? Then again, my friend didn’t either. I suppose we’re the odd ones.