Guest Post by Willis Eschenbach
Anthony has posted on a recent study (behind a paywall) of rice production in Rice yields, CO2 and temperature – you write the article. The article claims that rice yields are falling, and will fall further, due to temperature changes.
I said I’d write the article if someone would send me the actual study, and a couple of WUWT readers came through, my thanks to them. Here’s my take on what the authors have done.
First, the good. They have used actual data from farmer’s fields, rather than theoretical data or greenhouse experiments.
Figure 1. Rice Fields in Ha Giang
However, there are some troubling things in the study.
First, it covers a very short time span. The longest farm yield datasets used are only six years long (1994-99). Almost a fifth of the datasets are three years or less, and the Chinese data (6% of the total data) only cover two years (1998-1999).
Now, if they were comparing the datasets to temperature records for the area where the farms are located, we could get useful information from even a two-year dataset. But they are not doing that. Instead, they say:
Data series from the weather stations at the sites were too short to determine trends. Instead, trends in Tmin and Tmax were based on a global analysis of ground-station data for 1979–2004 …
Unfortunately, they have neglected to say which “global analysis of ground-station data” they are using.
But whichever dataset they used, they are comparing a two year series of yields against a twenty-six year trend. I’m sorry, but I don’t care what the results of that comparison might be. There is no way to compare a two-year dataset with anything but the temperature records from that area for those two years. This is especially true given the known problems with the ground-station data. And it is doubly true when one of the two years (1998) is a year with a large El Niño.
For example, they give the trend for maximum temps in the winter (DecJanFeb) for the particular location in China (29.5N, 119.47E) as being 0.06°C per year, and the trend for spring (MarAprMay) as being 0.05°C per year (I get 0.05°/yr and 0.04°C/yr respectively, fairly close).
But from 1998 to 1999, the actual DJF change was +2.0°C, and the MAM change was minus 1.0°C (CRU TS Max Temperature dataset). As a result, they are comparing the Chinese results to a theoretical trend which has absolutely no relationship to what actually occurred on the ground.
To try to find out which “ground-station data” they used, I compared their temperatures for China (29.5N, 119.47E) with the CRUTEM3, CRU TS, and GISS records from KNMI. However, I could not match their numbers, although I could get sorta close. Worrisome.
Next, they have not mentioned autocorrelation anywhere in their study. This makes me think that they have not adjusted for autocorrelation, which is particularly important with short datasets.
Next, they base their predictions for the future on a single computer model of the regional changes. It is widely agreed that computer climate models are not very good at predicting regional changes, so that part of their study seems very weak.
I am most mystified by their use of the 26-year temperature trend. Why not use the actual year-by-year changes in the local temperature? The rice is responding to actual temperatures, not to a mathematical trend … so why not compare yields to actual temperatures?
So once again, we have questionable methods used with uncited data to give alarming results. It is too bad, because their premise is good, and so is their general approach (use actual farm data).
Color me unimpressed …
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Ed Fix says:
August 11, 2010 at 3:06 pm (Edit)
A rice plant doesn’t care what happens in the next field
Oh I don’t know about that Ed. It might get in a bit of a paddy about it.
Don’t paddy fields create their own microclimate anyway? Isn’t that why it’s such a successful crop?
Table 9. Factors Contributing to Yield Losses (kg/ha of paddy) in Rice Production in South India
http://www.fao.org/docrep/003/x6905e/x6905e05.htm
Kerala
South India
Scarcity of irrigation water
Drought
Cold temperature at anthesis
Lodging
Low light intensity
Soil salinity
Low fertility
Zinc deficiency
Acid soils
Alkalinity
Iron toxicity
Weeds
Imbalanced use of fertilizer
Aged seedlings
Varietal problems
Socio-economic circumstances
Here is the problem and why we avoid non ag people from making claims in fields which they are not familiar.
So peer review means he snags some other city kids, econ majors and they are impressed.
” the Chinese data (6% of the total data) only cover two years (1998-1999).”
Typhoon Otto killed over 4000 in China from flooding, at the height of the rice season.
Oh come on Willis. This is easy. The change in rice yields are the effects of the absolutely indisputable teleconnections and a novel time compression statistical approach, which is shone to be skillful and robust.
[NOTE: Don’t forget to homogenize the PCAs]
I think the real point here is why was this study put together in the first place. It wasn’t a study to determine what increases or decreases rice yields, it’s purpose was to try to once again join the chorus of “be afraid, global warming is going to destroy us, so we have to act to stop it, be very afraid.” They could have just as easy put together a study showing rice yields rising due to better genetics, more use of fertilizer, and even higher levels of co2, etc. Are we running out of rice? No, the amount of rice produced is more of an economic function that anything else. (Raise the price high enough and you will flood the world with rice no matter what the temperature is.) It was put together for the political purpose of scaring us one more time that the sky is falling. Well we aren’t buying this crap anymore, well at least not on this web site.
This morning I was told by the news that temps were going up 7 degrees and seas would rise 7 metres because the large berg in Greenland was a symptom of runaway warming.
Now to rice yields. I haven’t read the paper but I notice a comment saying the “researcher” didn’t speak to any farmers. As a farmer I always had a pretty fair idea of why a crop did well/did badly. Not science but based on experience. So talking to the local farmers may have illicited a better answer than global warming. Unfortunately for the “researcher” summer crops grow better in hot conditions than in cool provided water is not a limiting factor.
Could it be that the drop off in production co-incided with the industrialisation of China and the move of the young away from farms to factories? I seem to recall newspaper stories about that time telling of the mass migration of young people looking for a better life in the cities. Take away the fit young workforce, particularly when Chinese farms are not mechanised, and you will have less field preparation, weed control and timely intervention. All three result in less production.
tty and David S, those were my first thoughts, too. Going the Yamal tree one better, Asian rice is apparently teleconnected in both space and time to remote growing conditions. It’s strange that this remarkable property was never discovered in greenhouse experiments, but perhaps it only shows up at larger scales.
This paper is actually quite exciting, since we may have at last discovered a significant source of the elusive chemical thiotimoline, the only known substance with even remotely similar properties:
http://en.wikipedia.org/wiki/Thiotimoline
Perhaps the idea is that the rice plant roots are rather long, and penetrate a long way into the earth’s crust (though not as far as the million degree region mentioned by our distinguished crazed vice poodle). Because of this deep probing of the planet’s thermal history, relatively small amounts of rice growth data, yield considerable information on planetary temperature data, and vice versa. Suffice it to say, that without considering _all_ the forcings we’ll never be able to understand, sorry model, sorry, create a set of illustrative unfolding future scenarios, which capture all the nuances. However, if we had any shred of knowledge or trust in our betters we would simply accept these findings without demur. Can I have a grant now please?
For the sake of argument let’s assume going up is temperature, CO2, and rice crop yields. What do we get? More snap, crackle, pop. Mixed with melted butter and marshmallows and allowed to cool it’s not too bad.
Willis, in the original thread they said it was the first ever study of its kind. I find that hard to believe. Perhaps they were refering to Western studies? In perusing their references, did you get any sense that they’d researched Asian literature for similar studies?
Thanks, and thanks for the analysis of the actual paper. Good job.
————-
I said in the other Rice thread that I’d check for historical records of Chinese rice studies. I didn’t have much Google-time, but I did find an interesting comment that the Chinese domesticated rice 6-8 kya. I am hoping to find historical records of the sort that “Emperor So-andSo” ordered hundreds of the court ‘smart-guys’ to study how to increase rice yields. OTOH, maybe it’s just been taken for granted for thousands of years that everyone knows good seed, good fertilizer, good weather, on a good plot is all you need for a bumper crop; why study what “everyone knows”?
Meanwhile, at RC, we have but a bloodbath taking place as to just how wrong and deceitful Lord Christoper has been!
Forget Nepal with its forged climate conspiracy, ignore Darwin and its agenda riven duplicity, gloss over Trenberths travesty but, mostly, celebrate that the the perfidious Peer has been revealed as the true anti-Christ by mental minnows.
Forget appeals to fair play, arguments underpinned by logical appeal, none of that is considered relevant by the withered ranks of those whom defend the indefensible.
Gavin and Chums, as much as you strive to associate with the bravery, or stupidity, of the Forlorn Hope of days thought extant the more your stance is revealed as stupid.
A promotion, however gratifying, within the losing side, is but a hollow victory.
Answer Anthony’s questions, respond to SMc’s probings but, mostly, quit your standard responses that place subjectivity, logic and hubris above reasoned argument.
Otherwise, just take the beating but without the bleating!
If the following report from the NWS is any indication, maybe we need to start growing more rice in coastal southern California!
…..SO FAR THE MONTH OF AUGUST HAS CONTINUED THE VERY COOL THEME.
THROUGH THE FIRST 10 DAYS OF THE MONTH…THE AVERAGE TEMPERATURE AT
LOS ANGELES AIRPORT WAS 63.8 DEGREES…6.3 DEGREES BELOW NORMAL. IN
ADDITION…THE AVERAGE HIGH TEMPERATURE WAS 68.8…NEARLY 8 DEGREES
BELOW THE NORMAL OF 76.4 DEGREES. RECORD LOW MAXIMUM TEMPERATURES
WERE SET OR TIED ON EACH OF THE FIRST 9 DAYS OF THE MONTH AT LOS
ANGELES AIRPORT.
AT SANTA BARBARA AIRPORT THROUGH THE 10TH….THE AVERAGE TEMPERATURE
OF 61.1 DEGREES WAS 7 DEGREES BELOW NORMAL. THE AVERAGE HIGH
TEMPERATURE DURING THIS TIME HAS BEEN JUST 67.2 DEGREES…NEARLY AN
ASTONISHING 11 DEGREES BELOW THE NORMAL OF 78.1 DEGREES.
AT SANTA MARIA AIRPORT…THE AVERAGE TEMPERATURE FOR THE FIRST 10
DAYS OF AUGUST WAS 59.8 DEGREES…4.2 DEGREES BELOW NORMAL. THE
AVERAGE HIGH TEMPERATURE OF 67.3 DEGREES WAS 6.7 DEGREES BELOW THE
NORMAL OF 74.0 DEGREES. THE HIGH TEMPERATURE OF 64 DEGREES ON THE
5TH TIED THE RECORD LOWEST MAXIMUM TEMPERATURE EVER RECORDED DURING
THE MONTH OF AUGUST.
One assumes that its actually worse than we thought since the rice production is apparently declining even though CO2 fertilizer effect should raise output.
I wish that just for a change that Anthony and WUWT could find a mainstream peer reviewed article on the environment that meets the standards and expectations of the readers of this web site. I am usually asked to peer review about 30 articles per year and the quality submitted manuscripts is actually quite high, although most papers benefit from critical reviews. After a while, one gets the idea that the readers of this web site are against all peer-reviewed science.
One word: Wormholes.
Hansen and his buddies are smoking pot in a circle, One of his buddies takes some acid, and says, wormholes are destroying the Earth by creating space/time rifts into the past Earth. They ate rice for dinner, so the obvious conclusion is that wormholes are created from rice.
And of course humans have to be thrown in there, because we wouldn’t be tree-huggers if humans were not evil and smelly.
Y’know, a couple years ago, when Obama was elected, a college professor in environmental sciences told me how impressed she was that the incoming Obama administration spent SO much time at the National Academy of Sciences to learn about what they were doing, and what they wanted to research. So why do I think that this paper is a product of the time they spent there and is what the administration wants to hear? It’s more than an embarrassment, it’s a travesty.
Forget the legions of false friends that bolster your defences Gavin. However admirably you’ve sustained them they’ll be the first to desert you.
For months now, you’ve stepped into the breeches that they’ve deserted, you’ve taken the flak, the dismemberment that they’ed deserved and with hora whimper.
Gav, you’re the Cowards answer to surviving. They say Run; you shout Fun. You die, they prosper!
You fight; they flight. Nice one.
BillD, some of the stuff that is being published is apparently for hyping in the media as opposed to being thoroughly researched. Besides, we don’t object to peer reviewed research as long as the review is valid and conducted by peers who have expertise in the science involved.
P.S., BillD, In fact we welcome it.
*blech!* Bad science yet again. Thanks for your work, Willis!
I’m more interested in the political drivers of this nonsense….is there some new focus on climate change in Asia? For example, look at the broo-hah over the IPCC’s mis-statements regarding Himalayan glaciers melting by 2035:
http://www.guardian.co.uk/environment/2010/jan/20/ipcc-himalayan-glaciers-mistake
What’s going on? Are the warmists seeking a new population to terrify? Considering that the PRC runs a classical iron-fisted command economy immune to nearly all outside influences, I have to wonder what they are thinking….
Willis,
Well, ya see? It’s like this: Proclamations of dooooooom and gloooooooom get all the headlines.
You know the drill by now: If it bleeds, it reads.
Kinda sorta like this: If you don’t have the facts, then pretend …
@RoyFOMR
I’ve tried to post at RC on that thread – drawing attention to the amusing contortion of this phrase: “Scenarios are images of the future, or alternative futures. They are neither predictions nor forecasts. Rather, each scenario is one alternative image of how the future might unfold.”
…which apparently is not from a comic Gilbert and Sullivan style opera – but from an IPCC report.
But sadly nothing gets through (the real climate patented gate keeping system is in play) making the thread a little one sided.
Fortunately, his Lordship can fend for himself – my fortran77 climatology prediction program says that the brewing oratorical onslaught may add a few degrees to the UHI effect.
Finally, does anyone else think that averaging high mountain tundra temperature anomalies with lowland plains anomalies, in order to adjust foothills anomalies, is a method that might possibly work but that it definitely would take careful watching, strict quality control, and a strong dash of common sense?
Yes. It might work, but I doubt it.
What’s to do… maybe use raw data, why are they messing with raw data so much?
If you massage it enough, maybe it can give you what you want.
How many GISS-padded data points does it take to equal 1 rice paddy?
It would appear that GISS is steaming the results prior to the rice being harvested.
“This paper is actually quite exciting, since we may have at last discovered a significant source of the elusive chemical thiotimoline, the only known substance with even remotely similar properties:”
Gary, this is neither the appropriate time nor place to dredge up contentious and acrimonious debate about which of the founding fathers of AGW science, Asimov or Lysenko was the first to discover the source of it all. I fear you are being deliberately mischevious in order to prevent ground-breaking, peer reviewed research from throwing more CO2 light on the bigger picture.