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Thermal Growing Seasons In The UK

May 4, 2016

By Paul Homewood


h/t Lord Beaverbrook 



Talking of early springs, DECC used to publish data on thermal growing seasons in central England. The last report was published for 2012 here. (I have asked them if they still update).


The data is based on the Central England Temperature series, and according to DECC:




And this was what the data showed:





As with so many other temperature graphs, we see that sudden rise between the mid 1980s and early 90s, since when things seem to have stabilised. Those two peaks, in 2000 and 2002, are now becoming a long distant memory, and in any event were not dissimilar to peaks in earlier years, such as 1822, 1833 and 1961.

We can also clearly see the sudden dip in trend in the 1960s and 70s. HH Lamb knew all about this, writing in his “Climate History and the Modern World” (p 274):





But, of course, the real news is that, whatever the cause, this increase in growing seasons is hugely beneficial for UK agriculture.

Not something you read too much about!

  1. May 4, 2016 11:59 am

    You must understand, that to the left, a benefit for UK agriculture in “unfair” to those who did not see this “benefit”. Thus you must be punishd. They always strive for the lowest common denominator just to be “fair.”

  2. May 4, 2016 12:58 pm

    On our planet with its seasons, global warming from CO2 has to appear as rising summer temperatures which persist through the following winter, resulting in a net gain. That is not what is observed.

  3. May 4, 2016 2:13 pm

    Paul, please let me know if you get an update source for data….

  4. Dorian permalink
    May 4, 2016 4:06 pm

    Something doesn’t look right.

    When you compare this graph of the growing seasons with that of the mean temperature for the UK in your previous post entitled “An Early Spring?”, they do not correlate.

    Look carefully. The graph from the An Early Spring, shows a slight negative trend from 1910 to 1980, whereas, the graph of length of growing season shows a positive bias.

    Now I find it hard to believe that as temperatures were becoming cooler between 1910 to 1980, and yet the growing seasons lengthened.

    Something doesn’t jive here. Where does this data come from?

    I think more scrutiny needs to be applied to the data. I’m beginning to smell a rat.

    I realize all too well that we are comparing a chart of mean values for an entire year, to a chart that is based upon a fixed period specified by tenuous starting and ending points. But there surely should be a strong a correlation between mean temperatures and length of growing seasons, which should illustrate a high degree of correlation. Which these two charts DO NOT.

    I smell a rat! Or the very least, more bad science….again!

    • Dorian permalink
      May 4, 2016 4:21 pm

      On further thought. I can only surmise, if the data from both charts are authentic (which these days is not something can be assumed to be), then the growing seasons to be lengthened with a slight temperature decrease, can only mean that the growing seasons may have lengthened but I suspect the quality suffered. Now, of course during this time farming practices have improved along with assistance from the agricultural sciences, but still there is something not quite right and more acute analysis of the underlying mechanisms between these two data sets and their expected correlation needs to be understood.

      Personally, I think this is a perfect example why such data can feed bad scientific discussions when there isn’t the proper systematic cross-over verification with other datasets in other supporting areas of science.

      Never take one dataset on its own merits!

  5. May 5, 2016 11:52 am

    Last June, while on that boring treetop walk in Kew Gardens, I read the tidbits of plant knowledge on bronze marker signs on the walkway fence. Here is one which was on a branch with buds: “buds are bursting weeks earlier because of global warming.”

  6. NeilC permalink
    May 5, 2016 1:43 pm

    Any study that just uses temperature to compare growing conditions is nonsense. For plant growth (depending on species), it needs the right number and wavelength of photons (light), the right temperature, the right amount of humidity and the right amount of CO2.

    I am sure these people learned about photosynthesis sarc/.

    Too low photon count, too low humidity, too low CO2, it doesn’t matter what the temperature is, no growth.

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