Time of the season

Climate change involves more than straightfoward warming, it also affects the patterns of weather and the seasons, as John Parker discovers in an excellent feature — What’s happened to the seasons? — in the Spring issue of The Economist’s Intelligent Lifemagazine. Parker’s done his homework, and his article is the best overview of recent changes in seasonal weather around the world, and the knock on impacts on agriculture and ecosystems that I’ve read. Here’s a sample:

Some seasons have vanished altogether. In Kashmir there used to be a brief rainy season between winter and spring, called tsonth -— three or four weeks of torrential downpours, bright sunshine and snow on the ground. But, says Rais Akhtar of the University of Kashmir, the state has not seen a tsonth for ten years. The first rainy season seems to have dried up in Uganda. In Ntchenachena, in northern Malawi, villagers used to describe four episodes of rain, each with their proper name and association with particular farming events. Since 2001, they say, the pattern can no longer be discerned.

Parker points to increasing unpredictability in “traditional” seasons posing a challenge to agriculture as well as dislocations in ecosystem linkages. We may even have seen an example of that in the last year in New Zealand. 2009 was a remarkable switchback between hot and cold weather. May was very cold, but August was the warmest in the 155 year record. And temperatures then flatlined through until the end of October, which was the coldest for 64 years. Check out the NIWA summary of the year, or MetService Weather Ambassador Bob McDavitt’s round up at Sciblogs. Perhaps global warming really is turning out to be global weirding.

[Zombies (I used to play for the same cricket team as Colin Blunstone, but never at the same time, unfortunately)]

10 thoughts on “Time of the season”

  1. This article discloses the immediate problem with adapting to climate change. How do farmers adapt if they dont know what the next year will bring? Look at our farmers in Northland now. In the future, a drought year or years will not be followed by a return to the average climate. That changes the whole way of doing agriculture. You cant brace for bad years or plan for good ones. The problem threatens even excellent efforts like transition towns. How do you build resilience in local food production in the face of constant and increasingly uncertain changes each season?

    This uncertainty will place strain on our social and legal systems as populations are driven beyond existing property and state boundaries to follow the climate to the best areas for growing food. There was a suggestion in, I think, a briefing paper for Copenhagen (cant find it now) that suggested fertile and relatively stable areas of the globe get assigned the task of being food baskets for the planet. If seasons are changing now then major social and legal change may be closer than we think.

    One thing is sure, the present system of laws is literally killing us and more of the same isnt going to help.

    1. This is an interesting and, to date, ignored point.

      consider Bangladesh, i got this from wikipedia.

      "Most parts of Bangladesh are less than 12 m (39.4 ft) above the sea level, and it is believed that about 50% of the land would be flooded if the sea level were to rise by 1 m (3.28 ft)."

      The population of Bangladesh is approx. 160 Million.

      I know this is rough, but you'll get the idea.

      80 million dispossessed if the sea levels rise. Where are they going to go? Do they become stateless? What will be their status, refugees? would member states of the UN be obliged to take them? All interesting and complex questions.

    2. Yes, I think NZ is a prime candidate for being a food basket. This is my main reason for disliking the proposed ETS here – we have the potential to be of global benefit and our carbon emissions are relatively tiny. That's the proposal John Key should have taken to Copenhagen.

  2. It seems like some good science could be done combining this material, Stu Ostro's work and the poleward compression of the atmospheric circulation. I suppose it would have to involve a GCM, but if so I suspect it might be beyond the capabilities of present ones.

  3. In June 2009 Otago University ran a forum on the global food crisis and the video from the sessions is available here.

    In Session 5 Prof Caroline Saunders from Lincoln explains why she thinks NZ should not try to "feed the world." You can download it and see what she had to say if you are interested.

    Chris Laidlaw interviewed Associate Prof Hugh Campbell from Otago Uni prior to the conference and Campbell said that "NZ cannot sustain a first world lifestyle by selling agricultural exports to people in Haiti". His view was that local farmers in third world countries needed to be supplied with the technology to improve their farming productivity. He went on to say that NZ agricultural exports to the third world tended to be aimed at the growing middle classes and gave the example of a joint venture between Nestle and Fonterra to market ice cream in Mexico.

  4. Re-the NIWA summary & Global Weirding, having watched a few interviews with James Lovelock, that caught my attention.

    3 minutes into the interview, he talks about what he sometimes refers to as climate flicker.

  5. According to Prof Saunders NZ's contribution to world production of cereals is 0.04%, meat is 0.55% and dairy is 2%. If we converted all class 1,2 & 3 land to wheat production and managed 8 tonnes per hectare (USA = 2.5t/ha) she estimates we would contribute 1.3% of world wheat supply.

    So more of an amuse-gueule really.

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