17 ms·

Using grape harvest dates to estimate summer temperature over 650 years

258 points by guerby 4y ago

guerby 4y ago
"Now the interesting part: the record of grape harvest date (GHD) in Beaune, France goes back to the year 1354. If we use the grape harvest dates to estimate summer temperature, and use outbursts of extremely hot summer as indicators of extreme summer heat, we can estimate it going back over 650 years:"
h2odragon 4y ago
Grapes feature at the end: "we can estimate" followed by a graph with a temperature axis. Would like to see the data and the formula for turning it to temperature used.
- taneliv 4y ago
  Regarding your desire for data, a research article referenced on the page: https://cp.copernicus.org/articles/15/1485/2019/ https://cp.copernicus.org/articles/15/1485/2019/ has a section on "Data availability," which seems to be relevant. Possibly the article altogether is interesting to you, I didn't read it (yet).
  - h2odragon 4y ago
    Thanks much!
- anigbrowl 4y ago
  Those dates are on record, and if we use them as proxy data to predict the summer average temperature, it does a remarkably good job, explaining 60% of the variance of the temperature data:
  - funnym0nk3y 4y ago
    What exactly is meant by explaining variance? I can't really make sense of that term.
    - anigbrowl 4y ago
      Correlation between the first derivatives of the date and temperature data, I believe.
    - ssfrr 4y ago
      Say you have some variable you are tracking, which is due to some underlying phenomenon, with some noise. In this case it's the average summer temperature (so each summer gives 1 datapoint). The simplest model is that the underlying phenomenon has some constant value, and the variations in your observations are all just random noise. You can estimate the true value as just the average of all the data. Computing the variance (the average squared distance from the true value) gives you a sense of how much noise there is. Now lets say that we make our model a little more complicated and allow that the temperature changes year-to-year. In fact, let's say that we know the true value for each year. Imagine overlaying this "true" plot on top of the noisy observations. We can re-compute the variance, but rather than looking at the error relative to the mean, we're looking at the error relative to this true value. This variance is likely to be lower than the first one we calculated, because some of that variance wasn't actually noise, it was changes in the true value. We've "explained" some of the variance. Now, rather than having access to the true values, we have some other variable that we think may be a good proxy for the temperature. In this case it's the grape harvest date. The first step is to find some mapping of the proxy variable onto the one that we're interested in (the article doesn't explain what mapping they're using). We assume that explaining more variance means that the (mapped) proxy variable is higher-quality. Note that the mapping function is essentially learned from the data. In a simple case it might be just finding a scale factor and offset using a linear regression, but it could be more complicated. You need to be a little bit careful that you're not overfitting. It's a good idea to use some of the data to fit the proxy variable, and then compute the explained variance on other data (train/test split).
boomchinolo78 4y ago
Would better weather forecasting move the relationship between weather and GHD?
legitster 4y ago
An impressive data fit. It's a bummer we don't have data going even older - the medieval warm period was between 950 to 1250. It would be an interesting comparison point.
- octonion 4y ago
  We do - https://www.washingtonpost.com/weather/2021/03/29/japan-kyoto-cherry-blossoms-record/ https://www.washingtonpost.com/weather/2021/03/29/japan-kyot... Same result.
  - legitster 4y ago
    As far as I understand, the medieval warm period is believed to be an anomaly localized to Europe. So it may not be reflected in data specific to Japan.
- octonion 4y ago
  See the Japanese cherry blossom data mentioned by someone else. It has blooming data since 600 AD.
- medion 4y ago
  Does it even matter anymore? Someone always trying to play devils advocate - the science is clear. The anecdotes are clear. We all know what’s happening. We are warming up and it’s our fault. It’s really simple.
  - radu_floricica 4y ago
    This part is simple, yes: it's warming and it's done by us. I'm a lot less clear on how this is bad. > This summer is what a 1.2°C-heated planet looks like. But in the future this won’t seem so bad — compared to the 1.5°C-heated planet. If we get to 2°C … The suspension points are there because trying to put actual words won't be as scary. A literal option would be "... we'll have summers an average 0.8C hotter". Which somehow fails to make me tremble in my boots, especially since it also means we'll have winters 0.8C warmer, which is a very very good thing.
cmrdporcupine 4y ago
Neat. The thing is that people selected for different things in grape harvests over different eras. The style of wine for Bordeaux "Claret" back in the 17th century for example was a very light ruby coloured wine. Now the typical Bordeaux is a very dark and extracted product. And consumers in general are often seeking out higher alcohol "hotter" wines, partially out of the influence of new world wines. So there could be more compounding factors in grape picking dates. Though in general seeking out a darker and higher Brix product would mean later picking dates, not earlier. But grape varieties planted have also changed somewhat overtime, too. Not so much in Burgundy where this article is talking about, though, so TFA's Beaune is actually a good choice as a point to compare.
- johnofthesea 4y ago
  That depends on variety. White ones like Riesling will suffer with the hotter temperatures / higher alcohol content.
  - novaRom 4y ago
    .. and plantations of grape vines will spread further to the north like it was few centuries ago
- pwarner 4y ago
  I imagine viticulture techniques have changed too. France is surely more stable than many places, they place huge value on traditional techniques, but fertilizer, trellis technique, yields could all evolve. Not that this disproves the data, or global warming, but climate isn't the only thing changing.
- mgaunard 4y ago
  Clairet is a type of rosé, and still is light-coloured.
  - dbcurtis 4y ago
    Is that a stealth James Bond reference?
missedthecue 4y ago
I wonder if they should account for evolutionary adaptions in the grape plants. This article doesn't seem to touch on that but it seems like a species of plant could change a lot over 650 years!
- readthenotes1 4y ago
  Like the watermelon https://images.app.goo.gl/8miHX48hfcHZ3rGQ7 https://images.app.goo.gl/8miHX48hfcHZ3rGQ7 Or the chicken https://www.vox.com/xpress/2014/10/2/6875031/chickens-breeding-farming-boilers-giant https://www.vox.com/xpress/2014/10/2/6875031/chickens-breedi...
  - throwawaymaths 4y ago
    Nah, that's just a watermelon at a different stage of ripeness. (I eat like five or six watermelons a year) I've gotten one like that, it's rare because we know how to pick em these days.
    - markdown 4y ago
      The seeds are dark brown/black, so it's ripe. And you won't find a watermelon these days with swirls in it.
      - throwawaymaths 4y ago
        You can if you buy seeded watermelons? Here is a modern picture of a modern watermelon with slightly less dramatic swirls. If you had bought it a few weeks earlier the swirls would be more prominent: http://sites.psu.edu/siowfa15/wp-content/uploads/sites/29639/2015/12/watermelon.png http://sites.psu.edu/siowfa15/wp-content/uploads/sites/29639...
        throwawaymaths 4y ago
        You can also see the swirls come out dramatically if you take a seeded watermelon and leave it in (a very cold, to avoid mold) fridge for a few weeks!
moultano 4y ago
Very similar chart to this one recording the date of Japan's cherry blossoms blooming since 600 AD. https://www.washingtonpost.com/weather/2021/03/29/japan-kyoto-cherry-blossoms-record/ https://www.washingtonpost.com/weather/2021/03/29/japan-kyot...
- doitLP 4y ago
  Wow very similar graphs
  - markjspivey 4y ago
    what do you mean by a similar graph if the original post only goes back to 1950 but japans goes back to 600?
    - bruce343434 4y ago
      Read the rest of TFA :)
    - tragiclos 4y ago
      The original post goes back to 1354.
      - markjspivey 4y ago
        Yes one of the graphs is from back then, so then I’ll ask again since 650 is not 1354 …
        markjspivey 4y ago
        im asking because of the medieval warm period and subsequent little ice age which occurred prior to the more recent big uptrend
    - mmazing 4y ago
      ^^^ Didn't read the article
greggeter 4y ago
quadcore 4y ago
When a lay person, including me, sees those studies, even though they are convincing to me, psychologically, there is an after taste of "its complicated" which I believe explains why some people fall in the deny pool. Ive realized by experiencing this summer in France, which feels like the hottest conditions Ive ever lived in (and Ive lived in Thailand and Morocco) that things are actually dead simple. We've landed on the moon, we've invented vaccines and smartphones; now picture how dead simple this is for us to predict the consequences of injecting CO2 in a test tube.
- Buttons840 4y ago
  It was my understanding that at the test-tube-scale we aren't able to demonstrate CO2 increasing the heat. Is this correct?
  - AlotOfReading 4y ago
    You can see them even at that scale. The original experiments by Tyndall that demonstrated the effect were in a tube [1] currently on display at the Royal Institution. [1] https://www.rigb.org/sites/default/files/styles/original/public/galleries/lblock_test_trh_1_2f03201e0257167.jpg https://www.rigb.org/sites/default/files/styles/original/pub...
  - deleted 4y ago
    [deleted]
  - bullfightonmars 4y ago
    Incorrect. This is a fundamental property of the molecule CO2. CO2 absorbs infrared radiation. In the atmosphere this property of CO2 prevents infrared radiation from radiating back out into space. > While transparent to visible light, carbon dioxide is a greenhouse gas, absorbing and emitting infrared radiation ... Absorption of infrared light at the vibrational frequencies of atmospheric CO2 traps energy near the surface, warming the surface and the lower atmosphere. Less energy reaches the upper atmosphere, which is therefore cooler because of this absorption. * https://en.wikipedia.org/wiki/Carbon_dioxide#In_Earth's_atmosphere https://en.wikipedia.org/wiki/Carbon_dioxide#In_Earth's_atmo... Or if you would rather Futurama explain it https://www.youtube.com/watch?v=6cjx4gJFME0 https://www.youtube.com/watch?v=6cjx4gJFME0
karol 4y ago
Good stuff. Still it's worth to look at the the ice core data from Greenland drilling.
a9h74j 4y ago
Great move in the article to show shifting distributions, not only a plot vs time of a shifting average etc. Possible confound not discussed: Have there been any changes in market or transportation or harvesting-technology or labor factors which would affect decisions about "harvest date" ? Were any new varieties systematically planted with/after X apparent breakpoint? Have direct effects, if any, of increasing CO2 been removed?
ggm 4y ago
A bit of a shame the kicker is only one chart at the end. I guess thats how "tell the story to bring the conclusion" works sometimes. I think more could be made of how the harvest data works, the chart is .. compelling.
version_five 4y ago
So first, the work is cool from a data analysis perspective, and it's always worth seeing this kind of thing for it's own sake. Other than that, who cares. We've driven the diminishing returns on new evidence of climate change to zero. There is not a smoking gun that is suddenly going to change perception. Stop using AGW as a political lever, and start looking for (implementing, because they exist) solutions, both in terms of carbon removal, and adaptation. The burden of proof has been met, we don't need more data. The only cause more data serves is preaching to the choir that wants to use AGW to implement large scale socialism. Stop doing that, and start solving the problem. (I still think the analysis is neat)
- guelo 4y ago
  > wants to use AGW to implement large scale socialism I would argue the problem is the hyper-vigilant anti-socialists since they have sabotaged all proposals, including market-based ones.
  - SV_BubbleTime 4y ago
    How many posts does it take this chain for someone to say nuclear doesn’t work, and then mock free market too? Aren’t you tired of it? We’ve all seen it a thousand times.
    - bythreads 4y ago
      I certainly am, It's just the same old echo-chamber reverberating across themes
    - guelo 4y ago
      If you looked into how nuclear power plants get built you'd probably call it large scale socialism. But you got all your talking points lined up in a perfectly sensible row, I wouldn't want to topple them over.
      - SV_BubbleTime 4y ago
Archelaos 4y ago
> This summer is what a 1.2°C-heated planet looks like. But in the future this won’t seem so bad — compared to the 1.5°C-heated planet. If we get to 2°C … A friend said something to me a while ago that I cannot get out of my head when people are complaining about a heat wave again: Think not so much that this summer is one of the hottest in the last, but one of the coolest in the next hundred years. I am tempted to replace 100 by 650 to match the article, or just talk about "the past" and "the future". But a hundred years makes it more tangible for me. My late grandparents were born just a little over 100 years ago, and my youngest niece and nephew may live to see the next 100 years.
- Proven 4y ago
- petre 4y ago
  650 years shows climate change deniers that this is not a natural cycle but human induced. That's why I'd like to see the 650y data analyzed just like the 1950-present instead of being thrown at the bottom of the article.
  - aceon48 4y ago
    650 years does not show a natural cycle. Pull up a temperature chart of hundreds of thousands or millions of years. The planet has been +- 10 degrees from here. There were millions of years without ice caps even
    - petre 4y ago
      Why bother? There weren't humans millions of years ago to record climate data or grape picking dates. Writing is 5500 years old. Climate change could have ended the Roman Empire. In wide terms we already know what will happen because it happened before. https://www.smithsonianmag.com/science-nature/how-climate-change-and-disease-helped-fall-rome-180967591/ https://www.smithsonianmag.com/science-nature/how-climate-ch...
    - adrian_b 4y ago
avsteele 4y ago
I thought that Europe experienced sustained cold years in the 1600s? You can see something near the start, but the crop failures where close to the end of the century. Surprised this plot doesn't show that. Maybe this method is heavily biased by the outliers? https://en.m.wikipedia.org/wiki/Little_Ice_Age https://en.m.wikipedia.org/wiki/Little_Ice_Age
- mellavora 4y ago
  wasn't that about the same time that European diseases wiped out large portions of the population of North America, reducing the amount of forest fires these people set (it was part of their resource management) and concordant reforesting, and thus the amount of CO2 in the air? https://phys.org/news/2011-10-team-european-ice-age-due.html https://phys.org/news/2011-10-team-european-ice-age-due.html
nl 4y ago
That "probability density function for summer temperature" is scary. It's a pity it probably isn't going to be easy to communicate to laypeople because it is undoubtedly the correct way to talk about climate data.
langsoul-com 4y ago
I wonder if newer farmers would farm inside buildings instead of outside. Seems too risky to plant shit tons, then random (and increasingly common) bad weather fucks everything up. Also, because most people farm outside, when bad weather destroys crops, indoor farmers can hike up the price and make bank.
- mellavora 4y ago
  I wonder if there is a reason why most people farm outside? What would it take to put a wheat field indoors?
- duckmysick 4y ago
  Some crops are grown indoors, in greenhouses, like tomatoes or cucumbers. It's also done on a commercial scale. Here's an example of a cherry tomato growing operation: https://youtu.be/4arNJoJ98Og?t=867 https://youtu.be/4arNJoJ98Og?t=867 The editing and the style might be a bit kooky but there's a certain charm to it. Here's a satellite photo of a cluster of smaller greenhouses in Spain: https://i.redd.it/5w3jvyq5nx811.png https://i.redd.it/5w3jvyq5nx811.png
cjsawyer 4y ago
Page is unreadable on iPhone because of a full screen popup ad that redirects me away
danwee 4y ago
I have the (weak) theory that non-developed countries were such because of the weather. I love reading and thinking... but in summer I cannot do any of that at home, it's just impossible for me to sit and study without sweating and feeling umcomfortable. So, my theory goes like this: For the people who like thinking/studying: hot weather does not invite you to stay at home and study/think, so you are forced to do something else. I imagine that as summers get longer and hotter, we'll see a diminishing in new ideas and the like because the people who like to think will be forced to do something else (laying on the cold floor to pass by the day).
- yunohn 4y ago
  > theory that non-developed countries were such because of the weather Don’t tell me you actually subscribe to the theory of undeveloped countries are so because of the heat, not colonialism or global exploitation. Your theory is beyond weak, its kindergarten level nonsense.
  - pvaldes 4y ago
    Yes, of course, colonialism was a curse for many countries, but we need to see further. Colonialism only works if a side has a much better technology than the other. And the fact is that Europe (subjected to harsh winters, global empires and constant wars) had a much better technology. Period. And that advances in war and travel, were based in lots and lots of solid science, created much before colonialism. You can't build a big ship or a bridge that stands 1000 years without solid math and skills. Being subjected to a strong religion that is against science o pro-science also played a huge part. The idea that when in danger of overheating or freeze our brain stop all machines and concentrates only in how to keep our body alive for one hour more is totally reasonable.
    - yunohn 4y ago
      > Colonialism only works if a side has a much better technology than the other. > You can't build a big ship or a bridge that stands 1000 years without solid math and skills. I refuse to engage with someone so woefully misinformed about the non West world. I’ll leave it to you to read and learn more. Open your mind…
MonkeyClub 4y ago
Anecdotal tidbits you may like: In Greece, grapes are harvested normally before the feast of the transfiguration of Christ (6 August, tomorrow). If you harvest earlier, they’re very Aesopian and sour, so farmers are really on the edge around these dates, constantly working to prepare the harvest. But if they try leaving the grapes on the vines for a few more days, so they ripen more, you might lose the lot in the rain that usually follows a couple days later the feast. There are few things more enjoyable these days here than taking random walks among the grape fields, chatting with the farmers, and leaving with a big smile and an even bigger bunch of grapes for the rest of your walk to the sea.
nkurz 4y ago
Tamino helpfully linked the underlying paper in his first comment: https://www.frontiersin.org/articles/10.3389/fpls.2016.00069/full https://www.frontiersin.org/articles/10.3389/fpls.2016.00069.... It's a clear and well written paper. While I assume its main conclusions are true (temperatures are hotter today and grape harvests are earlier than the historical average) there is a big hole in the logic used to show causality. Figure 5 and Table 1 show the main issue. As I understand it (and I applaud the authors for the clarity of their explanation) the original data from the 1600's shows a harvest date about 7 days earlier than the 1700 and 1800's. The decided that this didn't agree with records for neighboring regions where such records existed, so they "homogenized" the data by pretending the actual recorded harvest dates were 7 days later. Their justification for this is a one-time change in winemaking practice in Burgundy. Oh, by the way, according to the original records the difference harvest between the 1600's and today would otherwise have been just over 7 days. Lest I seem that I exaggerate, here it is in their words (Section 2.6): In the perspective of reconstructing past spring–summer temperatures, this bias must be taken into account. Otherwise it would have mean April-to-July GHD temperature-based reconstructions with maxima and minima ca. 1 ∘C warmer before 1718 than afterwards on the decadal scale, even though temperature measurements available in France since 1658 do not provide any evidence of such a warming during the period 1658–1718. To homogenise the Beaune GHD series we have then added 7 d to raw data prior to 1718. The Pearson correlation with April-to-July mean temperature in Paris for the period 1658–2018 is stronger with the homogenised Beaune GHD time series (r=0.76) than with the non-homogenised one (r=0.74). Anthropogenic changes in winemaking are the most likely explanation. They aren't necessarily wrong to make an adjustment here, but it completely undermines the causal argument they are making (or at least, that Tamino is making). While it is unlikely that there were no changes in winemaking in the last 650 year, assuming that there was one and only one major change and that it can be dealt with by uniform change to a single period of the data is fantasy. The raw data shows an early harvest, they change it to a later one, and then go on to argue that harvests are happening earlier than ever! Again, I presume their general conclusions are correct: recent temperatures are warmer, and recent harvests are getting earlier. But this paper really doesn't do a good job of showing the extent to which this is true, and it makes almost no effort to convince the reader that other cultural changes (which are almost certain to have occurred) didn't have effects of similar magnitude in unknown directions.
jonnycomputer 4y ago
I missed the part where they explained how they went from harvest date to temperature. I get that earlier harvest dates will imply warmer temperatures, but ...
- adammarples 4y ago
  Because they correlated well during 1950 — present
  - jonnycomputer 4y ago
    That is not what I meant. For example, did they fit a linear regression model, or, what?
Balgair 4y ago
Wow, you can see temp drops right near important historical events. The drop near the end of the 1700s is so close to the French Revolution.

258 points by guerby 4y ago

"Now the interesting part: the record of grape harvest date (GHD) in Beaune, France goes back to the year 1354. If we use the grape harvest dates to estimate summer temperature, and use outbursts of extremely hot summer as indicators of extreme summer heat, we can estimate it going back over 650 years:"

h2odragon 4y ago

Grapes feature at the end: "we can estimate" followed by a graph with a temperature axis. Would like to see the data and the formula for turning it to temperature used.

taneliv 4y ago
Regarding your desire for data, a research article referenced on the page: https://cp.copernicus.org/articles/15/1485/2019/ https://cp.copernicus.org/articles/15/1485/2019/ has a section on "Data availability," which seems to be relevant. Possibly the article altogether is interesting to you, I didn't read it (yet).
- h2odragon 4y ago
  Thanks much!
anigbrowl 4y ago
Those dates are on record, and if we use them as proxy data to predict the summer average temperature, it does a remarkably good job, explaining 60% of the variance of the temperature data:
- funnym0nk3y 4y ago
  What exactly is meant by explaining variance? I can't really make sense of that term.
  - anigbrowl 4y ago
    Correlation between the first derivatives of the date and temperature data, I believe.
  - ssfrr 4y ago
    Say you have some variable you are tracking, which is due to some underlying phenomenon, with some noise. In this case it's the average summer temperature (so each summer gives 1 datapoint). The simplest model is that the underlying phenomenon has some constant value, and the variations in your observations are all just random noise. You can estimate the true value as just the average of all the data. Computing the variance (the average squared distance from the true value) gives you a sense of how much noise there is. Now lets say that we make our model a little more complicated and allow that the temperature changes year-to-year. In fact, let's say that we know the true value for each year. Imagine overlaying this "true" plot on top of the noisy observations. We can re-compute the variance, but rather than looking at the error relative to the mean, we're looking at the error relative to this true value. This variance is likely to be lower than the first one we calculated, because some of that variance wasn't actually noise, it was changes in the true value. We've "explained" some of the variance. Now, rather than having access to the true values, we have some other variable that we think may be a good proxy for the temperature. In this case it's the grape harvest date. The first step is to find some mapping of the proxy variable onto the one that we're interested in (the article doesn't explain what mapping they're using). We assume that explaining more variance means that the (mapped) proxy variable is higher-quality. Note that the mapping function is essentially learned from the data. In a simple case it might be just finding a scale factor and offset using a linear regression, but it could be more complicated. You need to be a little bit careful that you're not overfitting. It's a good idea to use some of the data to fit the proxy variable, and then compute the explained variance on other data (train/test split).

boomchinolo78 4y ago

Would better weather forecasting move the relationship between weather and GHD?

legitster 4y ago

An impressive data fit. It's a bummer we don't have data going even older - the medieval warm period was between 950 to 1250. It would be an interesting comparison point.

octonion 4y ago
We do - https://www.washingtonpost.com/weather/2021/03/29/japan-kyoto-cherry-blossoms-record/ https://www.washingtonpost.com/weather/2021/03/29/japan-kyot... Same result.
- legitster 4y ago
  As far as I understand, the medieval warm period is believed to be an anomaly localized to Europe. So it may not be reflected in data specific to Japan.
octonion 4y ago
See the Japanese cherry blossom data mentioned by someone else. It has blooming data since 600 AD.
medion 4y ago
Does it even matter anymore? Someone always trying to play devils advocate - the science is clear. The anecdotes are clear. We all know what’s happening. We are warming up and it’s our fault. It’s really simple.
- radu_floricica 4y ago
  This part is simple, yes: it's warming and it's done by us. I'm a lot less clear on how this is bad. > This summer is what a 1.2°C-heated planet looks like. But in the future this won’t seem so bad — compared to the 1.5°C-heated planet. If we get to 2°C … The suspension points are there because trying to put actual words won't be as scary. A literal option would be "... we'll have summers an average 0.8C hotter". Which somehow fails to make me tremble in my boots, especially since it also means we'll have winters 0.8C warmer, which is a very very good thing.

cmrdporcupine 4y ago

Neat. The thing is that people selected for different things in grape harvests over different eras. The style of wine for Bordeaux "Claret" back in the 17th century for example was a very light ruby coloured wine. Now the typical Bordeaux is a very dark and extracted product. And consumers in general are often seeking out higher alcohol "hotter" wines, partially out of the influence of new world wines. So there could be more compounding factors in grape picking dates. Though in general seeking out a darker and higher Brix product would mean later picking dates, not earlier. But grape varieties planted have also changed somewhat overtime, too. Not so much in Burgundy where this article is talking about, though, so TFA's Beaune is actually a good choice as a point to compare.

johnofthesea 4y ago
That depends on variety. White ones like Riesling will suffer with the hotter temperatures / higher alcohol content.
- novaRom 4y ago
  .. and plantations of grape vines will spread further to the north like it was few centuries ago
pwarner 4y ago
I imagine viticulture techniques have changed too. France is surely more stable than many places, they place huge value on traditional techniques, but fertilizer, trellis technique, yields could all evolve. Not that this disproves the data, or global warming, but climate isn't the only thing changing.
mgaunard 4y ago
Clairet is a type of rosé, and still is light-coloured.
- dbcurtis 4y ago
  Is that a stealth James Bond reference?

missedthecue 4y ago

I wonder if they should account for evolutionary adaptions in the grape plants. This article doesn't seem to touch on that but it seems like a species of plant could change a lot over 650 years!

readthenotes1 4y ago
Like the watermelon https://images.app.goo.gl/8miHX48hfcHZ3rGQ7 https://images.app.goo.gl/8miHX48hfcHZ3rGQ7 Or the chicken https://www.vox.com/xpress/2014/10/2/6875031/chickens-breeding-farming-boilers-giant https://www.vox.com/xpress/2014/10/2/6875031/chickens-breedi...
- throwawaymaths 4y ago
  Nah, that's just a watermelon at a different stage of ripeness. (I eat like five or six watermelons a year) I've gotten one like that, it's rare because we know how to pick em these days.
  - markdown 4y ago
    The seeds are dark brown/black, so it's ripe. And you won't find a watermelon these days with swirls in it.
    - throwawaymaths 4y ago
      You can if you buy seeded watermelons? Here is a modern picture of a modern watermelon with slightly less dramatic swirls. If you had bought it a few weeks earlier the swirls would be more prominent: http://sites.psu.edu/siowfa15/wp-content/uploads/sites/29639/2015/12/watermelon.png http://sites.psu.edu/siowfa15/wp-content/uploads/sites/29639...
      - throwawaymaths 4y ago
        You can also see the swirls come out dramatically if you take a seeded watermelon and leave it in (a very cold, to avoid mold) fridge for a few weeks!

moultano 4y ago

Very similar chart to this one recording the date of Japan's cherry blossoms blooming since 600 AD. https://www.washingtonpost.com/weather/2021/03/29/japan-kyoto-cherry-blossoms-record/ https://www.washingtonpost.com/weather/2021/03/29/japan-kyot...

doitLP 4y ago
Wow very similar graphs
- markjspivey 4y ago
  what do you mean by a similar graph if the original post only goes back to 1950 but japans goes back to 600?
  - bruce343434 4y ago
    Read the rest of TFA :)
  - tragiclos 4y ago
    The original post goes back to 1354.
    - markjspivey 4y ago
      Yes one of the graphs is from back then, so then I’ll ask again since 650 is not 1354 …
      - markjspivey 4y ago
        im asking because of the medieval warm period and subsequent little ice age which occurred prior to the more recent big uptrend
  - mmazing 4y ago
    ^^^ Didn't read the article

greggeter 4y ago

quadcore 4y ago

When a lay person, including me, sees those studies, even though they are convincing to me, psychologically, there is an after taste of "its complicated" which I believe explains why some people fall in the deny pool. Ive realized by experiencing this summer in France, which feels like the hottest conditions Ive ever lived in (and Ive lived in Thailand and Morocco) that things are actually dead simple. We've landed on the moon, we've invented vaccines and smartphones; now picture how dead simple this is for us to predict the consequences of injecting CO2 in a test tube.

Buttons840 4y ago
It was my understanding that at the test-tube-scale we aren't able to demonstrate CO2 increasing the heat. Is this correct?
- AlotOfReading 4y ago
  You can see them even at that scale. The original experiments by Tyndall that demonstrated the effect were in a tube [1] currently on display at the Royal Institution. [1] https://www.rigb.org/sites/default/files/styles/original/public/galleries/lblock_test_trh_1_2f03201e0257167.jpg https://www.rigb.org/sites/default/files/styles/original/pub...
- deleted 4y ago
  [deleted]
- bullfightonmars 4y ago
  Incorrect. This is a fundamental property of the molecule CO2. CO2 absorbs infrared radiation. In the atmosphere this property of CO2 prevents infrared radiation from radiating back out into space. > While transparent to visible light, carbon dioxide is a greenhouse gas, absorbing and emitting infrared radiation ... Absorption of infrared light at the vibrational frequencies of atmospheric CO2 traps energy near the surface, warming the surface and the lower atmosphere. Less energy reaches the upper atmosphere, which is therefore cooler because of this absorption. * https://en.wikipedia.org/wiki/Carbon_dioxide#In_Earth's_atmosphere https://en.wikipedia.org/wiki/Carbon_dioxide#In_Earth's_atmo... Or if you would rather Futurama explain it https://www.youtube.com/watch?v=6cjx4gJFME0 https://www.youtube.com/watch?v=6cjx4gJFME0

karol 4y ago

Good stuff. Still it's worth to look at the the ice core data from Greenland drilling.

a9h74j 4y ago

Great move in the article to show shifting distributions, not only a plot vs time of a shifting average etc. Possible confound not discussed: Have there been any changes in market or transportation or harvesting-technology or labor factors which would affect decisions about "harvest date" ? Were any new varieties systematically planted with/after X apparent breakpoint? Have direct effects, if any, of increasing CO2 been removed?

ggm 4y ago

A bit of a shame the kicker is only one chart at the end. I guess thats how "tell the story to bring the conclusion" works sometimes. I think more could be made of how the harvest data works, the chart is .. compelling.

version_five 4y ago

So first, the work is cool from a data analysis perspective, and it's always worth seeing this kind of thing for it's own sake. Other than that, who cares. We've driven the diminishing returns on new evidence of climate change to zero. There is not a smoking gun that is suddenly going to change perception. Stop using AGW as a political lever, and start looking for (implementing, because they exist) solutions, both in terms of carbon removal, and adaptation. The burden of proof has been met, we don't need more data. The only cause more data serves is preaching to the choir that wants to use AGW to implement large scale socialism. Stop doing that, and start solving the problem. (I still think the analysis is neat)

guelo 4y ago
> wants to use AGW to implement large scale socialism I would argue the problem is the hyper-vigilant anti-socialists since they have sabotaged all proposals, including market-based ones.
- SV_BubbleTime 4y ago
  How many posts does it take this chain for someone to say nuclear doesn’t work, and then mock free market too? Aren’t you tired of it? We’ve all seen it a thousand times.
  - bythreads 4y ago
    I certainly am, It's just the same old echo-chamber reverberating across themes
  - guelo 4y ago
    If you looked into how nuclear power plants get built you'd probably call it large scale socialism. But you got all your talking points lined up in a perfectly sensible row, I wouldn't want to topple them over.
    - SV_BubbleTime 4y ago

Archelaos 4y ago

> This summer is what a 1.2°C-heated planet looks like. But in the future this won’t seem so bad — compared to the 1.5°C-heated planet. If we get to 2°C … A friend said something to me a while ago that I cannot get out of my head when people are complaining about a heat wave again: Think not so much that this summer is one of the hottest in the last, but one of the coolest in the next hundred years. I am tempted to replace 100 by 650 to match the article, or just talk about "the past" and "the future". But a hundred years makes it more tangible for me. My late grandparents were born just a little over 100 years ago, and my youngest niece and nephew may live to see the next 100 years.

Proven 4y ago
petre 4y ago
650 years shows climate change deniers that this is not a natural cycle but human induced. That's why I'd like to see the 650y data analyzed just like the 1950-present instead of being thrown at the bottom of the article.
- aceon48 4y ago
  650 years does not show a natural cycle. Pull up a temperature chart of hundreds of thousands or millions of years. The planet has been +- 10 degrees from here. There were millions of years without ice caps even
  - petre 4y ago
    Why bother? There weren't humans millions of years ago to record climate data or grape picking dates. Writing is 5500 years old. Climate change could have ended the Roman Empire. In wide terms we already know what will happen because it happened before. https://www.smithsonianmag.com/science-nature/how-climate-change-and-disease-helped-fall-rome-180967591/ https://www.smithsonianmag.com/science-nature/how-climate-ch...
  - adrian_b 4y ago

avsteele 4y ago

I thought that Europe experienced sustained cold years in the 1600s? You can see something near the start, but the crop failures where close to the end of the century. Surprised this plot doesn't show that. Maybe this method is heavily biased by the outliers? https://en.m.wikipedia.org/wiki/Little_Ice_Age https://en.m.wikipedia.org/wiki/Little_Ice_Age

mellavora 4y ago
wasn't that about the same time that European diseases wiped out large portions of the population of North America, reducing the amount of forest fires these people set (it was part of their resource management) and concordant reforesting, and thus the amount of CO2 in the air? https://phys.org/news/2011-10-team-european-ice-age-due.html https://phys.org/news/2011-10-team-european-ice-age-due.html

nl 4y ago

That "probability density function for summer temperature" is scary. It's a pity it probably isn't going to be easy to communicate to laypeople because it is undoubtedly the correct way to talk about climate data.

langsoul-com 4y ago

I wonder if newer farmers would farm inside buildings instead of outside. Seems too risky to plant shit tons, then random (and increasingly common) bad weather fucks everything up. Also, because most people farm outside, when bad weather destroys crops, indoor farmers can hike up the price and make bank.

mellavora 4y ago
I wonder if there is a reason why most people farm outside? What would it take to put a wheat field indoors?
duckmysick 4y ago
Some crops are grown indoors, in greenhouses, like tomatoes or cucumbers. It's also done on a commercial scale. Here's an example of a cherry tomato growing operation: https://youtu.be/4arNJoJ98Og?t=867 https://youtu.be/4arNJoJ98Og?t=867 The editing and the style might be a bit kooky but there's a certain charm to it. Here's a satellite photo of a cluster of smaller greenhouses in Spain: https://i.redd.it/5w3jvyq5nx811.png https://i.redd.it/5w3jvyq5nx811.png

cjsawyer 4y ago

Page is unreadable on iPhone because of a full screen popup ad that redirects me away

danwee 4y ago

I have the (weak) theory that non-developed countries were such because of the weather. I love reading and thinking... but in summer I cannot do any of that at home, it's just impossible for me to sit and study without sweating and feeling umcomfortable. So, my theory goes like this: For the people who like thinking/studying: hot weather does not invite you to stay at home and study/think, so you are forced to do something else. I imagine that as summers get longer and hotter, we'll see a diminishing in new ideas and the like because the people who like to think will be forced to do something else (laying on the cold floor to pass by the day).

yunohn 4y ago
> theory that non-developed countries were such because of the weather Don’t tell me you actually subscribe to the theory of undeveloped countries are so because of the heat, not colonialism or global exploitation. Your theory is beyond weak, its kindergarten level nonsense.
- pvaldes 4y ago
  Yes, of course, colonialism was a curse for many countries, but we need to see further. Colonialism only works if a side has a much better technology than the other. And the fact is that Europe (subjected to harsh winters, global empires and constant wars) had a much better technology. Period. And that advances in war and travel, were based in lots and lots of solid science, created much before colonialism. You can't build a big ship or a bridge that stands 1000 years without solid math and skills. Being subjected to a strong religion that is against science o pro-science also played a huge part. The idea that when in danger of overheating or freeze our brain stop all machines and concentrates only in how to keep our body alive for one hour more is totally reasonable.
  - yunohn 4y ago
    > Colonialism only works if a side has a much better technology than the other. > You can't build a big ship or a bridge that stands 1000 years without solid math and skills. I refuse to engage with someone so woefully misinformed about the non West world. I’ll leave it to you to read and learn more. Open your mind…

MonkeyClub 4y ago

Anecdotal tidbits you may like: In Greece, grapes are harvested normally before the feast of the transfiguration of Christ (6 August, tomorrow). If you harvest earlier, they’re very Aesopian and sour, so farmers are really on the edge around these dates, constantly working to prepare the harvest. But if they try leaving the grapes on the vines for a few more days, so they ripen more, you might lose the lot in the rain that usually follows a couple days later the feast. There are few things more enjoyable these days here than taking random walks among the grape fields, chatting with the farmers, and leaving with a big smile and an even bigger bunch of grapes for the rest of your walk to the sea.

nkurz 4y ago

Tamino helpfully linked the underlying paper in his first comment: https://www.frontiersin.org/articles/10.3389/fpls.2016.00069/full https://www.frontiersin.org/articles/10.3389/fpls.2016.00069.... It's a clear and well written paper. While I assume its main conclusions are true (temperatures are hotter today and grape harvests are earlier than the historical average) there is a big hole in the logic used to show causality. Figure 5 and Table 1 show the main issue. As I understand it (and I applaud the authors for the clarity of their explanation) the original data from the 1600's shows a harvest date about 7 days earlier than the 1700 and 1800's. The decided that this didn't agree with records for neighboring regions where such records existed, so they "homogenized" the data by pretending the actual recorded harvest dates were 7 days later. Their justification for this is a one-time change in winemaking practice in Burgundy. Oh, by the way, according to the original records the difference harvest between the 1600's and today would otherwise have been just over 7 days. Lest I seem that I exaggerate, here it is in their words (Section 2.6): In the perspective of reconstructing past spring–summer temperatures, this bias must be taken into account. Otherwise it would have mean April-to-July GHD temperature-based reconstructions with maxima and minima ca. 1 ∘C warmer before 1718 than afterwards on the decadal scale, even though temperature measurements available in France since 1658 do not provide any evidence of such a warming during the period 1658–1718. To homogenise the Beaune GHD series we have then added 7 d to raw data prior to 1718. The Pearson correlation with April-to-July mean temperature in Paris for the period 1658–2018 is stronger with the homogenised Beaune GHD time series (r=0.76) than with the non-homogenised one (r=0.74). Anthropogenic changes in winemaking are the most likely explanation. They aren't necessarily wrong to make an adjustment here, but it completely undermines the causal argument they are making (or at least, that Tamino is making). While it is unlikely that there were no changes in winemaking in the last 650 year, assuming that there was one and only one major change and that it can be dealt with by uniform change to a single period of the data is fantasy. The raw data shows an early harvest, they change it to a later one, and then go on to argue that harvests are happening earlier than ever! Again, I presume their general conclusions are correct: recent temperatures are warmer, and recent harvests are getting earlier. But this paper really doesn't do a good job of showing the extent to which this is true, and it makes almost no effort to convince the reader that other cultural changes (which are almost certain to have occurred) didn't have effects of similar magnitude in unknown directions.

jonnycomputer 4y ago

I missed the part where they explained how they went from harvest date to temperature. I get that earlier harvest dates will imply warmer temperatures, but ...

adammarples 4y ago
Because they correlated well during 1950 — present
- jonnycomputer 4y ago
  That is not what I meant. For example, did they fit a linear regression model, or, what?

Balgair 4y ago

Wow, you can see temp drops right near important historical events. The drop near the end of the 1700s is so close to the French Revolution.