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« Climate Resistance on catastrophism | Main | +++Lord Stern in email hacking+++ »
Tuesday
Feb092010

Pick a paragraph

This was a little experiment that turned up some interesting results. The idea was to pick a paragraph from the IPCC reports and look at its provenance, just to see if anything interesting turned up. It did.

Unfortunately it turned up so much, that I've decided only to analyse the first sentence of the paragraph. I've got a life you know.

Here's the paragraph. It's from WG2, Chapter 10, and its the start of section 10.2.4.1 which is about the effects of climate change on food production.

10.2.4.1 Agriculture and food production
Production of rice, maize and wheat in the past few decades has declined in many parts of Asia due to increasing water stress arising partly from increasing temperature, increasing frequency of El Niño and reduction in the number of rainy days (Wijeratne, 1996;Aggarwal et al., 2000; Jin et al., 2001; Fischer et al., 2002; Tao et al., 2003a; Tao et al., 2004). In a study at the International Rice Research Institute, the yield of rice was observed to decrease by 10% for every 1°C increase in growing-season minimum temperature (Peng et al., 2004). A decline in potentially good agricultural land in East Asia and substantial increases in suitable areas and production potentials in currently cultivated land in Central Asia have also been reported (Fischer et al., 2002). Climate change could make it more difficult than it is already to step up the agricultural production to meet the growing demands in Russia (Izrael and Sirotenko, 2003) and other developing countries in Asia.

First step was to look at the citations. I've linked PDFs where I have them.

  • Surprisingly for a sentence about rice, maize and wheat Wijeratne 1996 turns out to be about tea production in Sri Lanka.
  • I haven't been able to lay my hands on Aggarwal or Jin (I think Aggarwal should actually be Agarwal).(Update: Agarwal is a study on NW India, extract here - "It is concluded that the evidence of a yield decline in north-western India is not very strong at present.")
  • Fischer et al is a study published by an NGO, the Institute for Applied Systems Analysis (IIASA). This body seems to do research into environmental issues. THe study in question appears to be a special report paid for by the UN and as far as I can tell, non-peer reviewed.
  • Tao 2003a I can't find (Update:abstract here. Doesn't obviously support the case either)
  • Tao 2004 is a paper on variability in Chinese climate and how various oscillations (ENSO< EASM) affect crops.

So by the end of the first sentence, none of the cited papers that I can lay my hands on support the text as written, namely that "Production of rice, maize and wheat in the past few decades has declined in many parts of Asia".

Some of the reasons for this change became clear when I looked at the Second Order Draft. Here's the equivalent paragraph.

The increasing pressures of changes in climate and its variability would make it more difficult than it is already to step up the agricultural production to meet the growing demands in Russia. Increasing surface air temperature along with increasing intensity and frequency of El Nino, and the reduction in number of rainy days have heightened the water stress in many agricultural areas in China lowering the production of wheat especially in the Changjiang river, the yield of pasture areas in Qiaghai [sic] Province and the southern part of Gansu province and corn production in central China (Tao et al 2003a, Jin et al 2001, Tao et al 2004. Rice and wheat production in the Indo-Gangetic plains of South Asia, which increased in the 1970s and 1980s have in recent decade stagnated, attributed to the rising (minimum) temperatures during the growing season, resistance to weedicides, and decrease in soil productivities that appeared in large areas under rice-wheat sequence (Agarwal et al 2000). In Sri Lanka 30cm of soil has been eroded from upland tea areas over the years while in the lowland tea plantation production has been adversely affected by soil erosion and increased soil moisture deficit brought about by increase in temperature and drought (Wijeratne 2002).

Blimey. It's a remarkable change they've made there. Notice how we change from talking about what might happen to what has happened. Hasn't the whole purpose of the sentence changed? Doesn't this make a bit of a mockery of the review process? It's only one sentence, I know, but all the same.

Some things, however, become clearer.

  • The use of a paper about tea production in a sentence about cereals is clearly due to their having deleted the sentence about tea in Sri Lanka, but not the citation. Wijeratne's paper says that drought and rainfall affects tea growth. She doesn't say that is has. In fact she presents a graph showing that production and yields have risen since the 1980s. I guess it's just as well they deleted this sentence.
  • The Fischer et al citation, the NGO one, was new in the final draft. Note that carefully. The reviewers didn't have a chance to see it or criticise its inclusion.
  • Tao 2004 still doesn't support the text.
  • The other citations, I still can't comment on.

Finally to the expert and government review comments. These should help us understand who made the changes.

Or they should do, anyway. As far as I can tell, this radical rewrite between the second order draft and the final published piece was driven entirely by the authors. None of the reviewers requested the inclusion of Fischer et al. Nobody requested that tea be left out of the equation. And, nobody pointed out that Tao 2004 didn't support the text.

It's not right, is it?

 

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References (1)

References allow you to track sources for this article, as well as articles that were written in response to this article.
  • Response
    Wonderful idea — Bishop Hill chose a paragraph at random from an IPCC report and is proceeding to fact-check it to great amusement. From Bishop Hill: Pick a paragraphThis was a little experiment that turned up some interesting results. The...

Reader Comments (44)

I hope you are not surprised, and if so, why?

Feb 9, 2010 at 11:13 PM | Unregistered CommenterDon Pablo de la Sierra

A few weeks ago, I decided to take a look at Reviewer Comments (and Briffa's responses thereto) on the "Second-Order Draft Chapter 6: Paleoclimate IPCC WG1 Fourth Assessment Report" - in particular "6.6.1.1 What Do Reconstructions Based on Palaeoclimatic Proxies Show".

This was facilitated by accessing AR4SOR_BatchAB_Ch06-KRB-1stAug.doc in the Climategate files.

The results of my investigation were quite revealing, and are discussed in The climate change game ... Monopoly: the IPCC Version"

Feb 9, 2010 at 11:17 PM | Unregistered Commenterhro001

Aggarwal ea, 2000: http://www.ingentaconnect.com/content/ip/ooa/2000/00000029/00000004/art00006

Feb 9, 2010 at 11:21 PM | Unregistered CommenterJan Verbeeren

Maybe all of us "non-alarmists" should be given 1 sentence to review in similar fashion (like we did in 7th grade or so!). I'm ready for mine. Just let me know!

Feb 9, 2010 at 11:22 PM | Unregistered Commenterdfbaskwill

And please make it something to do with Mann, he's my favorite!!

Feb 9, 2010 at 11:23 PM | Unregistered Commenterdfbaskwill

Back to my favorite topic for this year -- El NIño as noted in AR4

While it may have an effect on air temperatures, it is a oceanic effect. It is the WATER that is getting warmer, and that is due to SOLAR heating and has NO causal relationship from/to the AGW, unless, of course, it is shown to be due to whales and fish farting and you consider them "anthropometric", which, if you do, is weird, to say the least.

Feb 9, 2010 at 11:24 PM | Unregistered CommenterDon Pablo de la Sierra

Wouldn't it be interesting to offer some sort of prize to the individual (or organisation) that actually finds a Chapter of an IPCC report that is wholly substantiated by peer reviewed literature without sensationalising the findings. A good honest assessment of the science and nothing but the science. Yes, I know it's a rather quaint idea, but you never know, somebody might actually find something trustworthy in one of them, ...............eventually!

Feb 9, 2010 at 11:25 PM | Unregistered CommenterBillyquiz

Unlike honest people Empirical Evidence and Truth do not count and are not necessary for the IPCC (Intergovernmental Panel of Climate Cheats) or (Intergovernmental Panel on Carbon Chicanery) and AGW (Al Gore's Wrangle) supporters.
Keep up the good work Bishop, we will sink the BS pushers eventually, sooner rather than later for my money.
Kind regards from an AGW sceptic in New Zealand.

Feb 9, 2010 at 11:26 PM | Unregistered CommenterMaurice J

Tao ea,2003a: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V8W-48S34S9-1&_user=794998&_coverDate=09%2F30%2F2003&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000043466&_version=1&_urlVersion=0&_userid=794998&md5=1afad01aa845b7d9ffac32742d0f5217

Feb 9, 2010 at 11:27 PM | Unregistered CommenterJan Verbeeren

"the yield of rice was observed to decrease by 10% for every 1°C increase in growing-season minimum temperature"

Prices usually decrease when supply goes up. Without further explanation this doesn't make a good agument for decreasing rice production.

Feb 9, 2010 at 11:31 PM | Unregistered CommenterSK
Feb 9, 2010 at 11:44 PM | Unregistered CommenterView from the Solent

Interesting. In the Fischer et al paper, the IIAS disavows ownership of the conclusions.

The findings, interpretations, and
conclusions expressed in this report are entirely those
of the authors and should not be attributed to the
International Institute for Applied Systems Analysis.

Feb 10, 2010 at 12:16 AM | Unregistered CommenterLes Johnson

Read the full manuscript of the Guardian's major investigation into the climate science emails and add your own annotations to create the definitive account of the controversy

Words fail me, they really do. I try to be so good on this blog, and not use words that need bleeping out, but really, who the [insert suitable expletive here] do they think they are fooling?

Feb 10, 2010 at 12:19 AM | Unregistered CommenterDennis

Have they taken account of a strong association between Marxist governments and declining crop (or any production) yields?

Feb 10, 2010 at 12:21 AM | Unregistered CommenterAC1

I don't get it. Pearce is still saying that the hockey stick is vindicated. I've seen that on other websites too, including the leftie wikipedia. But M&M demolished it didn't they? What about the hockey stick from red noise? How can this be?

Feb 10, 2010 at 12:23 AM | Unregistered CommenterBrian Williams

I don't get it. Pearce is still saying that the hockey stick is vindicated. I've seen that on other websites too, including the leftie wikipedia. But M&M demolished it didn't they? What about the hockey stick from red noise? How can this be?

Feb 10, 2010 at 12:23 AM | Unregistered CommenterBrian Williams

This issue would be funny if it were not so sad.

I grade the citations on research projects in a high school. Those would fail. How did these people get PhD's?

Feb 10, 2010 at 12:42 AM | Unregistered CommenterFai Mao

Brian Williams,

The fact that a hockey stick can be generated from red noise just proves that their methoology is robust! Q.E.D

Feb 10, 2010 at 12:49 AM | Unregistered CommenterEarle Williams

Aggarwal is the correct spelling. Aggarwal 2000 is from a book costing $28. Google scholar pops up some interesting links, one of which is:

http://www.agrar.hu-berlin.de/ntoe/asia/lectures-phil/crop-water-mngt/08/08-15.PDF


Conclusions
The results have shown that in most parts of
the Indo-Gangetic plains of India where ricewheat
is currently produced, climatic factors
allow a potential yield between 12.0 and
19.5 t ha-1. The potential is higher in the northwestern
regions compared to the eastern regions
and is related to temperatures and solar
radiation during crop season. These results are
based on the mean weather data. Therefore,
small deviations in these estimates are possible
at some locations due to climatic variability.

Feb 10, 2010 at 1:03 AM | Unregistered CommenterEarle Williams

From the Aggarwal 2000 abstract:

...
A significant annual yield decline was shown only when yield levels were high. It is concluded that the evidence of a yield decline in north-western India is not very strong at present. The yield trends may be partly related to the gradual change in weather conditions during the last two decades in selected research centres located in and around urban areas.
...

Looks to be SOP. Take one sentence out of context and generalize it to the entire region. Ignore all other peer-reviewed literature that points to the opposite.

Feb 10, 2010 at 1:08 AM | Unregistered CommenterEarle Williams

Leaving aside whether the preceeding catalogue of references are correct they do at least appear to be based on observed records. The assertion take from Fischer et al is based on computer models stretching out to 2080. Is it kosher to buttress evidence with 'evidence' in such a way?

From the second order draft quote

Rice and wheat production in the Indo-Gangetic plains of South Asia, which increased in the 1970s and 1980s have in recent decade stagnated, attributed to the rising (minimum) temperatures during the growing season, resistance to weedicides, and decrease in soil productivities that appeared in large areas under rice-wheat sequence

I am just guessing but could rice and wheat yields also have stagnated because there was only so much wheat and rice Norman Borlaug could coax out of crops by non-GM means.

Feb 10, 2010 at 1:09 AM | Unregistered CommenterGareth

Bishop & Friends, Thank you all very much, for the thoughts and work you all are putting into this effort to bring what has been hidden from the people, into the light. The more we know about the IPCC documents the more it seems, that behind it all there is a single voice leading the way, giving direction and defining the layout etc. Do you have any idea who the central producer would be for this? Not Pachauri?... Now,Obama and a new agency for climate change, in the face of all this? It is like the Twilight Zone...

Feb 10, 2010 at 1:15 AM | Unregistered CommenterTom

Yer Grace

Oh dear, oh dear, oh dear!

Lord Acton's observation that power tends to corrupt, applies to the IPCC as it does to the Hockey Gang.

Will the title of your next book be 'The IPCC Illusion as the Gold Standard'?

Feb 10, 2010 at 1:24 AM | Unregistered CommenterE O'Connor

"Now,Obama and a new agency for climate change, in the face of all this? It is like the Twilight Zone..."

Nope -- not at all. It IS the Twilight Zone. Interesting side light. Rod Serling use to live near Ithaca, New York, at least when he was writing, and he use to come to the bar in Ithaca I frequented. He was an interesting guy and bought me more than one pint. I doubt that he would be amused by the weird stuff that goes on today -- he was very serious, he was. A hard smoker, he was killed by cigarettes at the early age of 50. I once visited his house near the lake and saw his collection of yet-to-be-produced scripts -- hundreds. They are now in his beloved Ithaca College, well known to the horny males of Cornell for the abundance of co-eds in residence there. I really miss him. He was a very real person. He passed on in 1975

Feb 10, 2010 at 1:38 AM | Unregistered CommenterDon Pablo de la Sierra

Good Lord! Is nothing sacred? Cereal is for breakfast, tea for late afternoon. Where is Earl Grey when you need him?

Feb 10, 2010 at 2:27 AM | Unregistered CommenterJohn Blake

Good Lord! Is nothing sacred? Cereal is for breakfast, tea for late afternoon. Where is Earl Grey when you need him?

He's down at McDonald's having a burger and fries -- oops, chips.

Feb 10, 2010 at 2:55 AM | Unregistered CommenterDon Pablo de la Sierra

Well, I'll add my 2 cents in here (or is that shillings?)

Rice and wheat production in the Indo-Gangetic plains of South Asia, which increased in the 1970s and 1980s have in recent decade stagnated, attributed to the rising (minimum) temperatures during the growing season, resistance to weedicides, and decrease in soil productivities that appeared in large areas under rice-wheat sequence (Agarwal et al 2000).

Typical of statistical shenangians. List 4 reasons why something is (or may be) happening, without assigning (or even guessing) the relative influence of each. Anyone familiar with farming would understand "decrease in soil productivities" as played out soil. That is why we invented fertalizers. They wouls also understand "resistance to weedicides:. If you live in the US Midwest, there are lots of commercials for weedicides, and yes, their formulas keep changing with time to stay ahead of that pesky survival adaptation that weeds have.

Lastly you have the "rising minimum temperatures during the growing season". NOT the HIGH temperatures, but minimum temps. This would infer a LONGER growing season. Since min temps typically occur at night, a 1 degree C rise probably doesn't impact water evaporation much, since at night the cooling temps tend to deposit water vapor (dew) vs absorb it. Does a decrease of 14 C at night make that much difference compared to a 15 C drop?

Anyone know a good paper on dew formation and water vapor swings compared to daily temp swings?

Feb 10, 2010 at 6:05 AM | Unregistered CommenterTW in the USA

"the yield of rice was observed to decrease by 10% for every 1°C increase in growing-season minimum temperature"

In isolation like this, the sentence is meaningless. Each plant has a minimum and maximum range. If below the minimum or near it, rising temperatures INCREASE yield. A DEcrease in yield implies a predicate of "already at growth limiting heat" that is not a general condition but only specific to one place. (So, for example, as temperature rises one could move higher up a mountain or to more poleward directions to maintain yields).

BTW, Rice was commonly grown near my home town in California and The Rice Growing / Research Station was a 'big deal" in our county. One of the best rice growing regions in the world. Summer temperatures were typically 100+F ( 38 C) and highest I personally remember was 117 F ( 47 C ) one August. Though August was typically in the 105-110 F range ( 40 - 43 C ) for about 1/2 the days IIRC.

It's got to be VERY hot before rice growth slows down...

So I'd suspect this is a cherry picked very hot spot the quote is about, then generalized to the whole planet (and with the ludicrous implication that, by extension the other way, rice would grow best in Alaska... rather than California and Texas.)

A quick google shows at least one reference with "optimal" range for rice of 15 C to 33 C (or 59-91 F) with an upper bound at about 45 - 48 C ( 113 - 118 F ) and the usual lower bounds of about the freezing / frost point that limits most crops.

So we're talking at a minimum a place already at 33 C / 91 F temperatures and headed for over 40 C / 112 F to get significant growth suppression. That is NOT your typical place on the planet... and for every place warming from 35 C to 40 C there is another place warming from 10 C to 15 C and entering the 'optimal range'...

There, I did my sentence. Do I get another one now? ;-)

[BH adds: No, no, no. I want earlier drafts, review comments and citations checked out. Get back to your desk.]

Feb 10, 2010 at 8:02 AM | Unregistered Commenterchiefio

That 40 C / 112 F ought to be 44 C / 112 F
and
the 35 C to 40 C ought to be 40 C to 45 C

Probably ought to have picked on system and stuck with it rather than be transnational...

In any case, it's darned HOT! before rice slows down and it loves more warmth far after people are looking to leave town...

Feb 10, 2010 at 8:08 AM | Unregistered Commenterchiefio

Bish, this highlights how "every" problem can be attributed to AGW by the IPCC et al.

The Green Revolution failed bigtime, it has caused the problem now know as peak soil fertility. Ecologists rank peak soil as THE major issue for sustainable agriculture, ranked higher than peak oil, with pollution coming 3rd.

"The Green Revolution has been a failure. It has led to reduced genetic diversity, increased vulnerability to pests, soil erosion, water shortages, reduced soil fertility, micronutrient deficiencies, soil contamination, reduced availability of nutritious food crops for the local population, the displacement of vast numbers of small farmers from their land, rural impoverishment and increased tensions and conflicts. The beneficiaries have been the agrochemical industry, large petrochemical companies, manufacturers of agricultural machinery, dam builders and large landowners."

http://livingheritage.org/green-revolution.htm

Seems corpgovs/IPCC found a handy strawman in AGW to blame all the worlds ills on.

When one analyses the whole AGW thing, it really is a fantastical fiendish caper, they would have gotten away with it too... if it wasn't for those damn meddling bloggers :)

Feb 10, 2010 at 10:43 AM | Unregistered CommenterPeter

Great post. Enjoyed it.

Feb 10, 2010 at 10:58 AM | Unregistered CommenterHotRod

I suggested a sentence for each of us, but you must realize that I am lazy and will allow the experts here to actually do the work! I'll be too busy shoveling out from the 35 to 40 inches of snow we have outside in the past week. A coworker argued with me that this demonstrates "global warming" because warmer air means more extreme weather. Sheesh. With ridiculous rules like that, winning this war will prove difficult.

Feb 10, 2010 at 12:46 PM | Unregistered Commenterdfbaskwill

Earle Williams quoted
"From the Aggarwal 2000 abstract:...
The yield trends may be partly related to the gradual change in weather conditions during the last two decades in selected research centres located in and around urban areas."

Aggarwal would seem to understand the Urban Heat Island effect.

Feb 10, 2010 at 1:18 PM | Unregistered Commenterdearieme

Not sure if anyone has caught this one yet, but in the same chapter as posted about above in Table 10.3 the report cites an Environment News Service article. It looks like it was used as anecdotal evidence of climate change. Here's the article it referenced: http://www.ens-newswire.com/ens/nov2002/2002-11-26-02.asp

Feb 10, 2010 at 8:22 PM | Unregistered CommenterJ_M

@Earle Williams: Aggarwal ea, 2000 is an article in a magazine. I already gave the correct link in the3rth comment.

Analysis of yield trends of the rice-wheat system in north-western India

Authors: Aggarwal P.K.; Bandyopadhyay S.K.; Pathak H.; Kalra N.; Chander S.; Kumar S.

Source: Outlook on Agriculture, Volume 29, Number 4, 1 December 2000 , pp. 259-268(10)

Publisher: IP Publishing Ltd

Feb 10, 2010 at 9:32 PM | Unregistered CommenterJan Verbeeren

Bishop,

"none of the cited papers that I can lay my hands on support the text as written"

Translation: I didn't actually read all your citations and I only read the abstracts of most of the rest but I'll pretend this represents a 'fact-check' and insinuate that there is something wrong with your facts anyhow

As for 'pick a paragraph' one would be hard pressed to find a claim in the combined output of 'sceptics' that had didn't contradict known facts (if not the subsequent claim or itself), never mind one supported with peer reviewed literature. If ever any body of work deserved the observation "it's not right", it's that.

Feb 10, 2010 at 9:58 PM | Unregistered CommenterFrank O'Dwyer

Erm no. I've linked the papers where I could get them. Where I couldn't, I say so. Shouldn't all the papers support the text? That's the usual purpose of a citation.

Feb 10, 2010 at 10:22 PM | Registered CommenterBishop Hill

Bishop,

"Shouldn't all the papers support the text?"

Which paper does not? The only one where I see a link to a full paper is Tao2004

Among staple crops in China (rice, wheat, maize), maize production was very vulnerable to a strong EASM and El Niño phase

and Seasonal precipitation associated with EASM and ENSO had a significant correlation with maize yield variability. Water availability is a major constraint for agriculture production in the arid, semi-arid, and semi- humid regions of China (Tao et al. 2003). Crops during the summer monsoon period (June–September), e.g. maize, are subjected to seasonal rainfall variability associated with EASM and ENSO.

and
The results of this study show there was quite a large production variability associated with EASM and ENSO. Moreover, EASM precipitation variability (Kitoh et al. 1997, Hu et al. 2000) and the frequency and strength of ENSO (Grove 1998) can be expected to increase by global warming.

In which universe does that not support the text; due to increasing water stress arising partly from increasing temperature, increasing frequency of El Niño and reduction in the number of rainy days. It is part of the case.

Feb 10, 2010 at 11:06 PM | Unregistered CommenterFrank O'Dwyer

chiefio,Rememebr there are different types of rice also. I'm not a rice expert, but I would guess that each major area that grows rice uses a certain strain. As temps change, simply moving to a different strain would allow the area to stay productive. Same goes for corn and wheat. If it gets to hotter and dryer, plant soy beans. I've seen soy beans survive some brutal stretches of 100 degree days in the midwest with minimal loss (if any) of yields.

Part of all of these studies, assumes that we are at "optimum" conditions right now, and any change makes things worse. Well change is change. Things only get worse if you sit around and complain about it, instead of changing what you do/grow along with nature.

Feb 11, 2010 at 4:59 AM | Unregistered CommenterTW in the USA

Frank O'Dwyer,
"Moreover, EASM precipitation variability (Kitoh et al. 1997, Hu et al. 2000) and the frequency and strength of ENSO (Grove 1998) can be expected to increase by global warming. "

I find it unusual that references on studies now 10 yrs old keep getting used in these papers.

What has happened in the past 10-12 to verify the original study by Grove, and the ones by Kitoh and Hu?

Obviously you can't answer that question, but the point is, has reality come close to matching their predictions? I don't recall seeing any articles on massive crop failure in China. In fact Northern China is suffering from too much snow this year, same as Europe and Eastern US.

This seems to be common throughout the IPCC. The reports are 5 years or more out of date (compared to 2007). Since they used many non-peer reviewed ones, they could at least have gotten recent non-peer reviewed ones.

Feb 11, 2010 at 5:06 AM | Unregistered CommenterTW in the USA

Frank

That is a delicious piece of quote mining there. You missed out the start of the sentence - the bit where it says "Production of rice, maize and wheat in the past few decades has declined in many parts of Asia...". A paper saying rice is sensitive to A, B and C is not the same as one saying production has declined. Of the papers I can find (you missed that I've linked to the non-peer reviewed Fischer report too) none support the position.

There's a backstory here which I'll try to post on later.

Feb 11, 2010 at 6:43 AM | Registered CommenterBishop Hill

Bishop,

"A paper saying rice is sensitive to A, B and C is not the same as one saying production has declined."

Strawman. I didn't say it was. I quoted the part of the sentence which it clearly does support.

Feb 11, 2010 at 8:16 AM | Unregistered CommenterFrank O'Dwyer

I'm a bit bemused by your comment. The sentence says, in essence, yields have gone down because temperatures have gone up. The papers show that yields are sensitive to climate. They don't support any of the sentence.

Which paper supports the bit saying yields have gone down?

Feb 11, 2010 at 9:58 AM | Registered CommenterBishop Hill

Bishop,

"The sentence says, in essence, yields have gone down because temperatures have gone up."

The sentence says that yields have gone down due to water stress. It then lists reasons contributing to the water stress, only one of which is temperature. The others that are claimed are increasing frequency of El Nino and reduction in number of rainy days.

The Tao paper supports the attribution of the causes, at least the last two - i.e. it shows that they haven't simply pulled the ENSO and rainy days attribution and mechanism out of their ass.

As to whether the other papers support the rest, i.e. that there is a decline to explain in the first place, plus that ENSO has in fact been more frequent and rainy days have in fact decreased etc, I have no idea. Like you, I haven't read those papers. I don't even claim to know that it is a fact that yields have gone down. But I would expect someone claiming to be performing a 'fact-check' to not only read all the papers but also to check more widely as to whether or not the claim was in fact true. Just an idea. You haven't done either of these things.

So, where is the 'quote mining'? This is an accusation of dishonesty that I don't much appreciate.

Feb 11, 2010 at 1:58 PM | Unregistered CommenterFrank O'Dwyer

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