Guardian: CO2 Makes Rice Less Nutritious

Golden Rice

Golden rice (right) compared to white rice (left). By International Rice Research Institute (IRRI) –, CC BY 2.0, Link

Guest essay by Eric Worrall

Guardian author Nicola Davis is alarmed that adding CO2 to rice reduces the vitamins, minerals and protein – in some varieties of rice.

Climate change ‘will make rice less nutritious’

Nicola Davis

Thu 24 May 2018 04.00 AEST

When scientists exposed the crop to higher levels of carbon dioxide vitamin levels fell significantly

Rice will become less nutritious as carbon dioxide levels in the atmosphere rise, potentially jeopardising the health of the billions of people who rely on the crop as their main source of food, new research suggests.

Scientists have found that exposing rice to the levels of carbon dioxide that are expected in the atmosphere before the end of the century results in the grain containing lower levels of protein, iron and zinc, as well as reduced levels of a number of B vitamins.

“About two billion people rely on rice as a primary food source and among those that are the poorest, often the consumption of rice in terms of their daily calories is over 50%,” said Dr Lewis Ziska, a co-author of the research from the United States department of agriculture. “Anything that impacts rice in terms of its nutritional quality is going to have an impact.”

But with some of the varieties of rice apparently showing little change in levels of certain nutrients, the researchers say it might be possible to find or develop types of rice that will remain nutritious as the climate changes.

A drop in the nutritiousness of rice as a result of climate change could have profound health effects, particularly for those who rely most heavily on the crop, with the authors warning that it could affect early childhood development and worsen the impact of diseases including malaria.

Read more:

The abstract of the study;

Carbon dioxide (CO2) levels this century will alter the protein, micronutrients, and vitamin content of rice grains with potential health consequences for the poorest rice-dependent countries

Chunwu Zhu, Kazuhiko Kobayashi, Irakli Loladze, Jianguo Zhu, Qian Jiang, Xi Xu, Gang Liu, Saman Seneweera, Kristie L. Ebi, Adam Drewnowski, Naomi K. Fukagawa and Lewis H. Ziska

Declines of protein and minerals essential for humans, including iron and zinc, have been reported for crops in response to rising atmospheric carbon dioxide concentration, [CO2]. For the current century, estimates of the potential human health impact of these declines range from 138 million to 1.4 billion, depending on the nutrient. However, changes in plant-based vitamin content in response to [CO2] have not been elucidated. Inclusion of vitamin information would substantially improve estimates of health risks. Among crop species, rice is the primary food source for more than 2 billion people. We used multiyear, multilocation in situ FACE (free-air CO2 enrichment) experiments for 18 genetically diverse rice lines, including Japonica, Indica, and hybrids currently grown throughout Asia. We report for the first time the integrated nutritional impact of those changes (protein, micronutrients, and vitamins) for the 10 countries that consume the most rice as part of their daily caloric supply. Whereas our results confirm the declines in protein, iron, and zinc, we also find consistent declines in vitamins B1, B2, B5, and B9 and, conversely, an increase in vitamin E. A strong correlation between the impacts of elevated [CO2] on vitamin content based on the molecular fraction of nitrogen within the vitamin was observed. Finally, potential health risks associated with anticipated CO2-induced deficits of protein, minerals, and vitamins in rice were correlated to the lowest overall gross domestic product per capita for the highest rice-consuming countries, suggesting potential consequences for a global population of approximately 600 million.

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The “CO2 makes food less nutritious” narrative is my favourite climate absurdity.

To be fair to the researchers they appear to have conducted their research outdoors, keeping other factors as natural as possible.

But the fact some rice varieties don’t experience significantly reduced nutrient levels, even without selective breeding or genetic manipulation, completely undermines assertions that this issue presents any risk to human health. Delving into the research paper, some varieties even exhibited increased levels of key nutrients.

As the GM golden rice effort demonstrates, rice can and has been manipulated to enhance nutrient levels – in the case of golden rice, the rice was genetically modified to enhance vitamin beta-carotene / vitamin A levels. Shortage of vitamin A is a major cause of blindness in poor countries.

We have an entire century of genetic superscience to solve any issues with nutrient content. The creation of Golden Rice demonstrates we already have the technology to enhance individual nutrients. In 100 years we’ll probably have the technology to produce varieties of rice which sing sweet lullabies in the evening. Even if this slight reduction in nutrient content is an issue, it is an issue which will be well and truly solved long before it has any opportunity to cause harm to human health.


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“estimates of the potential human health impact of these declines range from 138 million to 1.4 billion, ”
and then goes on to say that no one has actually looked, it was just hysterical screaming
“However, changes in plant-based vitamin content in response to [CO2] have not been elucidated”
rice is a bred cultivated plant anyway……like Eric says, just grow a different one


The flawed assumption in this article is that it pre-supposes that the activists care one scintilla about science. They don’t . It’s an economic issue and no amount of science will change their minds. The point is to push the climate change agenda and facts don’t matter.
Same as the NDP in British Columbia. Their goal isn’t to save the environment or stop pollution, it’s to scare investors into backing away from any and all energy projects. But at the same time they have the unmitigated gall to want Alberta to keep shipping them gasoline.
Logic and science are irrelevant, so there is no need to discuss them.


…Logic and science are irrelevant, so there is no need to discuss them…
Correct because most of them don’t know any science, and think of logic as a cruel hoax invented to screw up their narratives.

Bryan A

Fortunately for ALL concerned, the afore mentioned B Vitamin group (B1, B2, B5, & B9) most affected are available in a wonderful supplement called B Complex so Any Future Loss in rice can already be compensated for today.

B Vitamin group
firstly, the experiment was fundamentally flawed, because the increase in CO2 was instantaneous, while the true increase is gradual over a period of decades. This flaw discounts the effects of evolution and hybridization.
secondly, the experiment ignores the ingenuity of humans, which routinely takes adversity and turns it into a benefit. Oriental culture, the concept of yin and yang, as well as buddhist teaching tells us there is no such thing as good without bad, or bad without good. Christianity as well recognizes that there cannot be light without darkness.
thirdly, adding CO2 increases yields, making more rice available. So total vitamin content can increase even if percentage/weight is reduced. Worrying about vitamins per grain of rice isn’t really a problem if there isn’t enough rice to go around.
lastly, if you want vitamin B, ferment the rice and produce sake. The yeast left in the vat it high in vitamin B, and the sake will help with the anxiety over vitamins.


So if we decrease the CO2 the rice will be more nutricious?


Yes, but ultimately disappear with enough decrease….

old white guy

I get a kick out of it. Expose an already picked crop to CO2 and say that natural occurrences will reduce the nutrition in the rice. That will not happen if the crop is indeed growing naturally.

Ed Zuiderwijk

It’s all relative. If the yield of carbohydrates increases, then per unit weight the other constituents decrease. In absolute terms the production of protein and or vitamins per plant may have remained the same, and I bet it did. Just an elaborate way to present us with a ficticious ‘problem’.


“It’s all relative. If the yield of carbohydrates increases, then per unit weight the other constituents decrease. In absolute terms the production of protein and or vitamins per plant may have remained the same, and I bet it did. Just an elaborate way to present us with a fictitious ‘problem’.”
I always try to read through the comments before making my own. You said close to what I was going to say. Thank you.

Original Mike M

It’s potentially worse than that if say the weight doubled but the vitamins only increased by say 1.8X. In reality for that case the vitamins went up too but just not quite as much. Alarmists can then claim a reduction of “vitamins per servings” while ignoring that there are double the number of servings.
The ultimate reply to them though is – who are you to say what the “correct” balance is supposed to be in the first place? They do exactly the same thing with temperature basically declaring that the current one is the “best” one.


they also failed to mention exactly WHAT level co2 they gassed em with
expected levels was all they mentioned
lotta leeway for fluffing figures in that.


The fact is that almost all the nutrients are thrown away when it is turned into white rice. The same with wheat too. So it is utterly irrelevant how much the ratio of carb to protein increases.

Kristi Silber

It seems to me that you make a pretty big assumption in your statement that, “The flawed assumption in this article is that it pre-supposes that the activists care one scintilla about science. They don’t . It’s an economic issue and no amount of science will change their minds. The point is to push the climate change agenda and facts don’t matter.”
There is nothing I can see in this article about any activists – so where is the assumption? I suppose you could be referring to Eric’s comments – in which case you might be right.


The Guardian.
Comic…….as ever.

Malcolm Carter

Are these the same people who support the EU’s and Greenpiece’s opposition to golden rice. Ah but consistency was never the object.


They’re consistent in one thing, their greed for money and a comfortable life for themselves, at the expense of developing countries.
They don’t care that between 120,000,000 (WHO estimate) and 200,000,000 (GWPF estimate) people in developing countries will die prematurely by 2050 (only 32 years away now) from conditions contracted by inhaling smoke from burning wood and dung for cooking and heating.
So much for the greens humanitarian claims.

Kristi Silber

“They’re consistent in one thing, their greed for money and a comfortable life for themselves, at the expense of developing countries.”
I imagine many “warmists” would say the same thing about “skeptics.”
“They don’t care that between 120,000,000 (WHO estimate) and 200,000,000 (GWPF estimate) people in developing countries will die prematurely by 2050 ”
Warmists might respond, “Skeptics want to trade indoor air pollution for the increased ambient air pollution that is likely to result from a push toward fossil fuels as the only energy source worth considering. Through their fight against any mechanism of decreasing CO2 emissions, they are showing their disregard for the health and well-being of those who can least afford actions to respond to climate change…and do so because they refuse to make any sacrifice whatever of their own.” Interesting that both “sides” think the other is selfish and greedy.
I’ve come to see things differently, and would not now say the above, being aware of the roots and rationale of skepticism, and of skeptics’ understanding of the role of fossil fuel-based development in bringing better lives to the developing world.
I think there is value to this idea. Nevertheless, I think it has challenges of its own. For example, development takes resources (esp. capital and expertise) – who will provide them? When and how will it happen, how long will it take, and who decides its nature? Are economic and political instability taken into account? Is it any more ethical to push the typical Western fossil fuel-based developmental paradigm on a sovereign nation than to push for “sustainable development”? Are skeptics assuming an affordable grid-capacity energy storage system is not viable, or won’t be commercially available within the next several years, or does this simply not matter? Are they taking into account that some countries will always have to import FF, and that prices and availability in the future are unknown? What about those villages who have benefited from solar or wind long before they are likely to be connected to the grid – are they taking the wrong path? Do skeptics take into account the health impacts of ambient air pollution that often accompany high fossil fuel use in urban areas?
What kind of message do you think is sent by America’s refusal to participate in the Paris agreement? Is it one of caring about the welfare of other less fortunate nations?
Saying anyone simply “doesn’t care” about the lives of others is a pretty bold accusation. You may believe that there won’t be net negative long-term impacts of climate change for people in developing countries, but that doesn’t mean others don’t care just because they don’t agree.
Do you suppose it is only conservative/skeptic philanthropists who fund research into more efficient, low-emission stoves, or pay for their production and distribution?
It’s far easier to think poorly of others than to understand them – something I know from experience! I want to take a harder path, even though I stumble along the way.
(General note to all: before you start insulting me, consider that I have not clarified my position toward development, and that I’m not always speaking for myself here. I hope to be able to converse civilly.)


That is the culprit right here. High caliber researchers are capable of break-through discoveries or inventions, like golden rice. The lesser ones are complaining about climate change.


Digging down a little deeper than panic mode, it makes complete sense that, with more CO2, plants can make more material from CO2 and water, using less nutrients and even less water. You end up with more calories relative to nutrients, so just eat more rice. Duh.
How about giving the people more rice, makes sense to me because, with increased CO2, the yields will go up, and thus, giving people the appropriate nutrition means giving them more rice. Wow, that was hard to solve, not!


Absolutely my thoughts when reading the article.

Kristi Silber

If only life were as simple as you make it!
“…just eat more rice. Duh.” It’s this a little like saying, White flour has few nutrients, so people should eat more of it? Your idea might work if people had as much rice as they wanted, and if eating more rice were a good nutritional alternative overall, and if it weren’t for the fact that other research has shown “Increases in rice yield at elevated [CO2] were constrained by limited N supply. The detrimental effect of rising temperature on spikelet fertility and harvest index were not be fully counteracted by elevated [CO2] effects. Together, the results of this meta-analysis suggest that rising [CO2] and warming accompanied by low N supply are unlikely to stimulate rice production, especially with the current trajectory of emissions scenarios.” (
Turns out that N is a common limitation to CO2 response in many plant taxa, and changes in N content is seen in many taxa in response to increased CO2 (N is necessary for protein synthesis; changes could have far-reaching ecosystem effects). Some farmers can just buy fertilizer. Others can’t.

1. I wonder if there is a correlation between people who worry about the decline in nutritional quality of rice and those who would object to consuming genetically-modified varieties that can more-than-compensate for nutritional deficiencies (e.g., golden rice) .
2. One of the farmer’s job is to improve traits of their crops. I figure they have 50-100 years to fix this problem.

It seems that with Grants seeking a specific outcome, any study can find fault or negative with just about anything.


I would really like to know actual percentage reduction of each nutrient.
Most of the nutrition (including fiber, vitamins, and minerals) is absent from white rice by removing the husk, bran, and germ of brown rice
It is very cheap to fortify white rice and is often done.
White rice is really just treated as a source of energy to which other high nutrient foods are added for a healthy diet.


…like adding black beans and Tabasco


Yes, I don’t think anyone eats a white rice only meal..

Bryan A

I do almost…I add condensed Tomato Soup
Sometimes just a little butter.


This “study” is hogwash. It is weeping and wailing and gnashing of teeth over nothing.
Red beans and brown rice make a complete protein, however crude it may be. Use red beans canned in chili sauce (tomatoes!) and add some chorizo sausage for flavor, plus smoked sausage for texture and beef broth for the liquid required to cook the rice.
I don’t think I’ve read anything that is as bluntly void of nutritional information as that so-called study, WRT what I did read of it. It is hogwash and another hand-out-fill-my-purse money grab.

Richard of NZ

One problem with your otherwise very sensible solution is in your additional nutrients. Beef broth is not acceptable to Hindus and Sikhs while sausage, because it is made from pork, is not acceptable to Moslems. That is 2/3rds of the peoples affected by chronic malnutrition. Much of these peoples dietry needs are forbidden to them.

Ric Haldane

Jeff, Many people in the Philippines are lucky to get one bowl of rice per day. The rate of childhood blindness is high. Adults develop other problems form lack of vitamin A. Most people in the US have no idea what poverty is. Greenpeace has been doing its best to keep golden rice out of the country.


Richard of NZ – that’s my recipe for red beans and rice. It’s a filling, very nutritious dish that needs only cut veggies on the side as a complement.
While I did not mean to slight the Hindu or Sikhs, the same dish can be made without any meat at all, by using vegetable broth in place of beef broth, and no sausage is required at all. My bad that I did not mention this. The chili sauce is strictly canned tomatoes with chili seasonings, no meat involved. Muslims can use beef or chicken sausage.
The sausage I use is made of beef, because pork does not agree with me. There is always a solution.
The real issue is that the study is baloney, written up by people on a money-grab, not much else.


Without a single shred of quantitative data, on what % change of these nutrients were measured, given in the abstract, it’s a safe bet that this is merely activist pseudoscience.

Previous studies on the same subject have indicated a loss of about six to seven percent.

Kristi Silber

Abstracts often don’t go into numbers. That doesn’t make it pseudoscience. If you want to know numbers, read the article. It’s open-access.

Kristi Silber

“I would really like to know actual percentage reduction of each nutrient.”
You could always read the article.
Here’s a start:
“When grown under field conditions at these anticipated [CO2] a significant reduction (an average of −10.3%) in protein relative to current [CO2] was observed for all rice cultivars “


There is no loss of protein. The percentage goes down because the CO2-richer atmosphere permits so much more sugar to be produced, with less water loss.

Tom Halla

I do wonder what the yield improvement was for the high CO2 fields, and if it was a matter of lack of soil nutrients causing the decline in quality of the rice.

Malcolm Carter

I wonder whether the change in nutrient was measured relative to dry mass of the rice or if the rices had different moisture content or variable fibre content. Good healthy rice may have more fibre or moisture and appear to have less nutrition per gram. It is better to determine nutrient ratio to dietary caloric content.


And if they really wanted to conduct a scientific study, they would determine the bioavailability of these nutrients from CO2 enriched rice vs rice grown in today’s atmosphere.

Dennis Sandberg

Exactly, could it be anything else? Doubtful. Bigger plants would require more water, fertilizer and soil nutrients.


Scientists exposed the crop to CO2, and the yield grew a lot. How do you spin it?
“When scientists exposed the crop to higher levels of carbon dioxide vitamin levels fell significantly.”
No further questions, Your Honor!


In methods, they tell they assessed the yield. in results, they don’t report it. I wonder why.
Another thing is they reported the fertilized to “maximize yield”. How did they know they actually used the optimum, given tubes had different CO2?
I’d say the report looks very suspicious.


*they* fertilized


I’m curious what the effect of CO2 enrichment on rice yield was. Paper seems to mostly concentrate on nutrient content. Would expect an increase in yield with increasing CO2.


Or what Tom said…

NW sage

That goes along with my line of thought. Just how MUCH are the nutrient values decreased (if statistically significant at all) and are other varieties normally available which contain MORE of the ‘lost nutrients’ and thus make up the difference?


I’m starting to get an idea of what all these dumb claims are for…if the climate begins or continues to cool they can STILL demonize CO2, not for warming but for all the bad other things they claim it can do. Where is the study that shows that adding CO2 increases crop yields, and that in greenhouses, they pump CO2 up to around 1000 ppm to increase yields, quickly. Oh, yes, not alarming…

Kristi Silber

I don’t have access. How did they estimate the amount of change in yield with rising CO2?
This is a computer model based on climate in a variety of areas in eastern India.


Just as one would expect, increased plant food in the air increases yield of rice, a C3 plant:
Growth and yield responses of rice to carbon dioxide concentration
Rice plants (Oryza saliva L., cv. IR30) were grown in paddy culture in outdoor, naturally sunlit, controlled-environment, plant growth chambers at Gainesville, Florida, USA, in 1987. The rice plants were exposed throughout the season to subambient (160 and 250), ambient (330) or superambient (500, 660, 900 μmol CO2/mol air) CO2 concentrations. Total shoot biomass, root biomass, tillering, and final grain yield increased with increasing CO2 concentration, thegreatest increase occurring between the 160 and 500 μmol CO2/mol air treatments. Early in the growing season, root:shoot biomass ratio increased with increasing CO2 concentration; although the ratio decreased during the growing season, net assimilation rate increased with increasingCO2 concentration and decreased during the growing season. Differences in biomass and lamina area among CO2 treatments were largely due to corresponding differences in tillering response. The number of panicles/plant was almost entirely responsible for differences in final grain yield among CO2 treatments. Doubling the CO2 concentration from 330 to 660 μmol CO2/mol air resulted in a 32 % increase in grain yield. These results suggest that important changes in the growth and yield of rice may be expected in the future as the CO2 concentration of the earth’s atmosphere continues to rise.
A study from last year:

Silvia Rodriguez

John, greenhouses pump 1000pm in the air and soil in greenouses is not depleted. Open farms are very different. This was answered on quora:

Joshua Smith

This Guardian story seems to follow up on a fascinating story in Politico, the Great Nutrient Collapse, that showed how challenging it was to do research:


I found a list of problems global warming is supposedly going to/is causing. Don’t think this one is on it but it only has 100 on the list. There must be many more to worry about.

This author has given up on counting.


We can safely say “Climate Change” causes any and all calamities available, may be excluding Solar eruptions.


What alarmists seem incapable of grasping is that, since rice is a C3 plant, more CO2 in the air improves its yield dramatically and reduces its water need.
The “less protein” canard arises because more CO2 means that plants can make more carbohydrate, ie sugars. If more nitrogen isn’t provided, then the percentage of protein will fall, not because there is less protein, but because there is more carbohydrate. If more N become available, then higher CO2 allows more protein to be formed as well.
Proteins are made out of amino acids, which, as their name indicates, are organic compounds containing amine (-NH2) and carboxyl (-COOH) functional groups, plus a side chain (R group) specific to each:comment image
Same goes with the B vitamins, which also contain nitrogen. Rice doesn’t make fewer vitamins under increased CO2. It makes the same amount, but produces more carbohydrates, hence the share of vitamins declines relative to the increased total nutritional value of the crop. Vitamins E and K should be helped by having access to more carbon.


That’s just what I suspected. The non-carbohydrate nutrients decrease by volume if growing time is decreased or volume is increased for same amount of time. Maybe feeding the plant more of those materials would help.

Bryan A

Supplemental B Complex negates the issue


100%…thanks Felix

J Mac

Thanks for that clear explanation. I was surmising that some other nutrient(s) must be limiting the protein and vitamin production. You ‘filled in the blank’ for me!

Thanks felix for that clear explanation. Other previous studies did the same thing: plants grew larger but with lower vitamin concentrations as a % of mass.


Felix Thanks from me too.


So….farmers will supplement the increased CO2 with nitrates aka fertilizer, just as they have done….for centuries?

Kristi Silber

“What alarmists seem incapable of grasping is that, since rice is a C3 plant, more CO2 in the air improves its yield dramatically and reduces its water need.”
Who do you mean by alarmists? It seems like most people who think about this at all know that CO2 fertilization exists. (However, I’d point out that even with increased water use efficiency, water availability can put constraints on yield.)
“The ‘less protein’ canard arises because more CO2 means that plants can make more carbohydrate, ie sugars. If more nitrogen isn’t provided, then the percentage of protein will fall, not because there is less protein, but because there is more carbohydrate. If more N become available, then higher CO2 allows more protein to be formed as well.”
How is this a “canard”? The physiology behind it doesn’t matter if a given quantity of rice will have lower protein when grown at higher CO2 levels. The researchers fertilized to “maximize yield;” presumably they took into account that CO2 enrichment enhances growth and didn’t want N to be a limiting factor.
In other experiments, “Increases in rice yield at elevated [CO2] were constrained by limited N supply.” (
So is there a point at which low soil N shows up in rice nutritional value without decreasing yields? This seems to be your argument.
But the real reason your argument doesn’t show this a “canard” is that many people can’t afford to buy a bunch of fertilizer to offset nutrient loss even if they knew about it, and given the dependence of some people on rice as a staple of their diet it could have health impacts.
Am I misunderstanding you? Or is my reasoning faulty?


You are misunderstanding me and elementary science.
There is no loss of protein. It stays the same, as long as N remains the same. What is gained is more carbohydrate. The fact that more CO2 in the air means more sugar in the rice is a good thing. Only the percentage of protein falls, without more N added.
Why is this hard to understand?
There is no downside to more plant food in the air. If you add more N, you also get more protein, ie amino acids.


It’s a canard because there is not less protein. Only the percentage goes down, thanks to higher yield of carbohydrate.

Kristi Silber

Judging by your remarks, I understand you fine. Higher photosynthesis leads to higher carbs for the same amount of N (protein). I’m talking about the nutritional value of the rice: nutrients per unit carbohydrate, if you like. It’s not the answer to eat more rice to get the amount of nutrients one used to get in a normal serving. Some people get 70% of their carbs from rice because they can’t afford food with higher nutritional value, and (so goes the argument) the loss of nutritional value per unit of rice is not a good thing…especially if the same applies to other plant-based foods. One can have a full belly every day and still be malnourished.
Just adding more soil N is not always an option – and whether that would change nutritional value anyway has not been demonstrated. With greater water use efficiency there is less water uptake per unit biomass – but that also means it’s possible proportionally less N (and other nutrients) is being absorbed. That is, “If you add more N, you also get more protein, ie amino acids” isn’t necessarily true. There is no reason to believe N was limited in this experiment.
“As evidenced by over a hundred individual studies and several meta-analyses, projected increases in atmospheric [CO2] can result in an ionomic imbalance for most plant species whereby carbon increases disproportionally to soil-based nutrients (9–11). This imbalance, in turn, may have significant consequences for human nutrition (12, 13) including protein and micronutrients. ”
(Of course, looking at this from the perspective of whether this will be important 50 or 100 years from now is a whole nuther ball game, but that is not my point.)


You’re all very welcome. I’m glad my explanation was helpful to you.
I’m a fifth generation PNW wheat rancher, with relatives who are 7th generation. Not counting fellow soft white wheat farmer relatives from Oz, with thunder from down under. Not to mention chunder from too much barley mash.


I’ve noticed most of the ammunition that skeptics have used tend to be diminished or dismissed later on by ‘science’ studies.
Case in point was the melting ice cap on Mars. A ‘science’ study was later commissioned that ‘found’ out that the change in surface albedo was the reason.
It is amazing what the elites are going thru in order to push us into mega-cities and live a meager ‘sustainable’ life. I’m seeing the same thing kind of push happening with the unprecedented attacks on Trump (who I did not vote for) to get rid of him.

It’s not so much the elites, but ideologues who use emotional arguments to sway others when the facts are not on their side. They can’t accept a truth that goes against what they want to believe, and this is the result. Often, this is concurrent with conflating two unrelated things for the purpose of transferring the emotional trigger.
For example, in the immigration debate, where the rights and privileges of legal immigrants are conflated with those of people who illegally circumvented the immigration process. Another is the gun control debate where the rights and privileges of legal gun owners are conflated with the criminally insane who may use them in the commission of a deadly crime. In both cases, the emotional arguments should be obvious.
Look at just about any polarizing issue and the side on the wrong end of the facts will use emotion, transference and psychological projection to sway public opinion. The way to tell which side is wrong is by noticing which side is using these kinds of tactics. Unfortunately, the public is easily swayed by fake news and fake facts, especially when the fakeness is supported by strong emotional arguments that presume the fakeness in the first place.


I think the WEF is an elitist group:
From the pace of climate action to saving our oceans, world leaders had plenty to say about the environment during the World Economic Forum’s Annual Meeting 2018 in Davos.
Here’s a quick recap of some (but by no means all) of the key moments from this week’s sessions.
The greatest threat to civilization
As leader of the fastest growing major economy in the world – as well as the world’s largest democracy – Indian Prime Minister Narendra Modi started the week by telling the Davos audience that climate change is the greatest threat to civilization.

My questions are:
Is this supposed reduction in nutrients caused by an increased amount of CO2 or by a limiting supply of other nutrients in the environment where the crop is grown?
If the yield can increase, then are enough other nutrients in the ground available to give the plant a chance to produce a proportionately greater quantity of nutrition, along with that yield, or does the size of the yield “dilute” the supply of growth nutrients that would support the greater amount of nutrients forming in the plant?
Is it just a matter of adding more nutrients to the soil?


Trials at Horsham’s Australian Grains Free Air CO2 Enrichment (AGFACE) program has in the past found with the wheat trials, increased yields can be accompanied by lower protein levels.
However, and not much attention is paid to this by the detractors, the lower protein when combined with the higher yields means that the amount of protein produced per planted area is actually greater.
This is nothing new, wheat protein levels can be higher in drier years when yields are lower, and lower in wet years when yields can be higher.


So is it better to eat less nutritious rice than none at all?


No, it is better to eat more of the rice (of which there is more available) and to get the same total amount of protein, vitamins and minerals with some extra carbs.

R. Shearer

There is more protein and B vitamins in 1 egg (50 g) than in 3 times the same mass of rice.

David LM2

CO2 will produce more rice, so if it’s less nutritious the simple answer is to eat the extra that was grown.

Richard of NZ

Or use the excess to grow Saccharomyces. Yeast is a very rich source of B group vitamins and a good source of protein. Any saki coincidentally produced is a bonus.

michael hart

If you increase any one beneficial nutrient, then the others must necessarily decrease, relatively speaking.
If the pig I eat has more protein, then The Guardian would say that the fat content has gone down.
Total dishonesty or stupidity. Or, more likely, both.


The Guardian despises numbers, since maths and arithmetic are only used by evil White Males.

And remember, the incredible shrinking Guardian has recently gone full tabloid.

The more nitrogen in the nutrient the greater deficit they found.
They also grew the plants in a field with identical environments (except for CO2)
I think it is reasonable to guess that the fast growing, higher yielding CO2 plants would need extra nitrogen based fertiliser to achieve equal nutrient content.


They don’t give actual numbers. From other studies that I have seen the decrease in nutrients is less than the increase in mass.


I also don’t see numbers for CO2 – they claim it is measured but don’t give data about what levels produce the effects they claim. Given the priests of AGW penchant for fiddling data they might be showing us effects not achieved at less than (say) 800ppm.
(80 years x 3ppm per year = 240 +410 = 650ppm – allowing for their confidence that rates will keep rising to doom us all, it’s reasonable to wonder if they took things to 800ppm.)


No co2 numbers- like the co2 in the the test tube experiment that was probably 500,000-1,000,000ppm compared to around 350ppm. Talk about gaming the system – they never give the figure.


What I didn’t see in the paper is any testing of the circles themselves. At 90m in size it is feasible the differences could as easily be due to different soil mixing with the water. I think they should have done it 3 times, varying each circle each growing season to exclude location differences.

Joe Adams

There was a big double page article on this study in China Daily, 2 years back. All the figures use the system of lying by using the truth. They give ONLY the PERCENTAGE of less protein and nutrients and NEVER mention the increase in yield. The grains, no doubt, have the same or more nutrients but contain a lot more starch. Bigger grains. Bigger yields. Cheaper. People eat as much as they can afford, so not an Earth shattering problem.
An analyst of the study added that, even if CO2 is not warming the planet, here is a reason to combat it.
When these shysters start talking percentages on climate and sustainables, dig in and ask, ” Percentage of what?”


Yes I was looking for increase in yield figure, and could find nothing.
Surely that is highly relevant and easily determined.


You’ll find a global supply and utilization table in pdf format at this USDA site:

Yes. And this also applies to anomalies. Anomalies of what?

Kristi Silber

The study is about the effect of increased CO2 on nutritional value in rice. Why is yield highly relevant? How would it change the results? For the connection to be made, the researchers would have to go into economic analyses or eating habits, both of which are beyond the scope of the research.

Tom Halla

Kristi, it is mostly that rice is not anywhere near a complete diet, but more a source of calories. Neither is maize, thus the Mexican farming trinity of corn, beans, and squash.
Further, the objections assume desperately poor people, basing their diet on one staple. Anyone with a bit of economic space would grow additional crops, or feed some of the grain to chickens or pigs, so the dietary outcomes are a mostly imaginary worst case.


I tried to post yield increase data, but WordPress censored me. Again.
The yield increase from more CO2 is huge. Rice is a C3 plant, so gains significantly from more vital plant food in the air.

Kristi Silber

Joe, couldn’t have been the same article, as this was just published.


So in their controlled experiments, with its controlled amount of soil and nutrients…. They forgot that the increased plant growth would tax the limited nutrients in the soil and exhaust them before the plant matured….The plants lacked enough Nitrogen to produce Protein, so the plants replaced the deficit with increased starch… That’s my take on what happened. It’s more to do with poor soil, not excess CO2.
But whatever… It’s all about the government Funding anyway.

Kristi Silber

J.H. The plants were fertilized for maximum yields. Your take on what happened is assumption, as is your statement about government funding. But hey, you’re free to think what you want.


It makes no difference.
The majority of people who eat rice,and for whom rice forms a major part of their diet, eat white rice…that is brown rice with the husk and germ removed.
And the husk and germ is where the majority of the vitamins and micronutrients are.
Brown rice takes much longer to cook than white rice and is not suitable for sweet dishes and many cooking styles. Locally available green vegetables, such as sweet potato leaves, provide many of the required vitamins.
And protein ? No one relies on rice for protein.
People get that from additions to rice … chicken, fish, even insects.
So the fact that higher CO2 levels may lead to a drop in micronutrient and protein levels in some rice varieties is inconsequential. People don’t eat the bits of rice that contain the micronutrients and they get their protein from other sources.
An academic beatup


Some Vietnamese I know told me that it was also a cultural thing. Only poor people ate colored rice. The rich and middle class all eat white rice so that is what the poor want to emulate. Brown or yellow just won’t cut it with that level of cultural conditioning.


White rice also keeps much longer than brown because the oil in the bran layer can go rancid.
Also some say that anti-nutrients found in brown rice like phytates, bind to nutrients preventing them from being absorbed.

Kristi Silber

I think you mean bran rather than husk, which is inedible and removed on brown rice, too.

Tsk Tsk

Greenpeace and their fellow travelers at the Grauniad and other “environmentalists” have aided and abetted the deaths of millions of undernourished children in their insane opposition to Golden Rice. That action alone has resulted in lowering the potential nutritional value of rice more than any increase in the overall caloric value of CO2-fertilized rice “dilutes” the protein & mineral content of said rice.
These people (and I’m being generous calling them that) have no redeeming qualities at all. They want to force the whole planet to join their death cult.


Rice and most grains have only one saving grace and that is they can be stored without refrigeration. They have a high glycemic load and a low nutritional density which is totally opposite what you want from food.

Ed Zuiderwijk



“high glycemic load” translates to a fast increase in blood glucose levels:
“low nutrient density” is self-explanatory.

Tim Beatty

Here’s reality: Total calories produced goes up. People can eat for nutrition and they will get more calories. The increased yield means more food. If the poorest rice nations aren’t limited by calories, they aren’t poor. More CO2 puts more food on the table for constant nutritional value. It ends hunger. Only rich nations with excess calories and obesity would be affected negatively but not to the point where nutrition is affected.

Alan Tomalty

Well it is legitimate to assume that farmers would not go to extra expense of adding nitrogen to the soil when CO2 levels double; HOWEVER in the study they only used 17 varieties out of a total of 40000 different varieties of rice on the planet. AND in the case of zinc 4 varieties showed more AND in the case of iron 2 varieties showed more. For protein the highest drop was 19% with 1 variety -6% and another one -5% and another one -10% (error factor of +/-10%). For B5 3 varieties were < 5% decline while for B9 1 variety declined only 10% For B2 2 varieties declined < 10% and for B1 1 variety had only 12% decline. As the article said all these can be boosted with genetic engineering . So far this is the only negative I have ever encountered with increasing CO2 levels in the air and it is a very slight negative at that.

Alan Tomalty

I guess the extra crop yields outweighs the negatives anyway because if you are too poor to get your nutrients in any other way than rice then you probably wouldnt be stuffing your stomach with the poorer nutrient rice in the year 2084 to the point that you couldnt eat extra of it to make up the difference. I assume that the extra crop yields would bring the price down in 2084 so that the individual family in Bangladesh would be able to buy more of it and eat more of it to make up the difference in nutrients. Perhaps an information campaign in the year 2050 as a head start to inform the worlds poor to eat more rice if they have it on their menu. Somehow I dont think this will be a problem that will surface at that time. If it is a problem by 2050 im sure that the UN can handle the information campaign By diismantling the IPCC there would be more than enough money to handle the information campaign.

Mark - Helsinki

So they take a balanced plant life cycle and increase one factor significantly, that would otherwise adapt over several generations of plant for the next 70 years at around 2ppm a year.
hmm, reminds me of dropping corals into acid, to represent 70 years of predicted slow changes in pH.

Geoff Sherrington

The logic is wrong.
People will find enough food to eat, or die.
If there is more weight of food from CO2, they will find more weight of food, hence compensatory low-concentration nutrients.
They will eat until their nutrient needs are supplied, or die. The chemical analysis of their mainstay food is immaterial. Geoff


Yes, I believe your logic is wrong! Taken from Livestock data: Feeding animals too much poor quality food ( roughage) only serves to fill their Bellies making for satisfaction – and then starvation because the Energy release is insufficient to maintain Heat and life. Equally a diet low in Minerals causes problems and then can go on to state likewise with Vitamin content.. I certainly don’t gobble loadsa food to get more Vits n Mins. WE knew all this in the 70’s. …….

Geoff Sherrington

You have introduced a straw man by moving from discussion of a normal diet to a ‘poor quality food(roughage)’.
My argument is about such a small change in food composition that it would scarce be noted.
The shift from normal, to that with reduced levels of some vitamins and minerals on a per weight basis caused by CO2 enrichment, is so small that it is ludicrous to start talkin about roughage comparisons.
It is also misleading to gather together a clutch of vitamins and minerals that you claim are decreased by CO2 enrichment, then suggest that there will be a nutritional problem. First you have to establish that the original levels of one or more of these were marginal, so that any decrease would lead to a deficiency. It would be extremely unlikely that all in the clutch would be found deficient. The argument is meaningless unless and until a particular nutrient or vitamin is identified as marginal normally, so that its further reductions could cause a problem. The old bucket with holes analogy says that the one to watch is the lowest one; patch it, then wait until the water rises to find the next one to patch. You need not patch all of the holes in the bucket to get use out of it.
It would also help, critically, to give numbers to support the generality of the argument as presented at the start here, an argument of hand waving grandeur but little fact. Geoff

Kristi Silber

To be fair, Geoff, your analysis was not exactly heavy on facts. Although I must admit that the logic of “People will find enough food to eat, or die.” is hard to challenge.


So? Eat mair tatties ! ( for the linguistically challenged = Broaden your dietary habits and eat more potatoes )


RAH: Government Money Makes Many “Scientists” Turn Into Babbling Idiots.

Moderately Cross of East Anglia

I wonder if the people who are running the Guardian into the ground ever really think about the reasons why it is being abandoned by what was a technically numerate readership in droves, leaving only a sad collection of Maoists, enviro-imperialists and well meaning students buying into its poorly prepared alarmism.

Yes. My own research reveals that increase in atmospheric CO2 markedly reduces the intelligence of the Gardian’s output.

Guardian losses fell this year.
I don’t know whether that is from creative accounting or from political advertising payments from TeamHillary and remain.


“About two billion people rely on rice as a primary food source and among those that are the poorest..”
Well yes, but that won’t be the case in 70 years time!
This research takes CO2 levels a the end of the century and then uses today’s poverty figures – insanely stupid.
Extreme poverty has halved in the last few decades, as has poverty in places highly dependent on rice, such as India and China. There is no reason why it should not continue to fall. This is just beyond stupid.


The people who put out this “study” are the same ones who have been doing everything in their power to increase poverty.

Ed Zuiderwijk

This was totally predictable. The warmistas know they are losing the argument that CO2 causes the planet to boil. So they are now softening up the politicians by claiming that, ok CO2 doesn’t cook us, but, hey, look what other ‘harm’ it does. Anything, any lie, any absurdity will do to keep the green levers on our energy supply, to control us.


It’s not a good food anyway. It’s fine for the starving and needy, but Ideally we want plants grown without chemicals in soils with quality minerals.

Geoff Sherrington

Why on Earth do you promote “plants grown without chemicals in soils with quality minerals”?
You are taking the pi$$, are you not?
“Quality minerals” ARE “chemicals”. One and the same thing.
Each time you pull a carrot out of the ground and take it home to eat, you are taking away from your garden soil a number of minerals such as those providing Fe, Cu, Co, Mo, Se to name a few, the so-called nutritional trace elements. The soil has some ability to provide more of these from its reservoir, to grow the next crop. However, with much farming today, you are taking these away faster than the soil can regenerate the. If you do not truck in and add to the reserves from time to time, your yields will drop each harvest and in a few years it will not be worth the effort to plant each year.
Not just trace elements – phosphorus and potassium are two major nutrients than can exhaust enough to materially reduce year on year harvests. The most efficient way to replenish these is by mining phosphate rock and potash rock and this is what is done on a grand scale. You can make small replenishments by adding organic material like dung or compost, but in the overall equation these will also diminish over seasons unless you add the mined product.
But, there is no way you can make your carrot grow year after year if you do not follow the wealth of farming knowledge that has led us to the ‘chemical’ addition of potassium, phosphorus (and nitrogen, if other pathways are not adequate).
The current fuzzy trendy of ‘organic farming’ is a disaster waiting to happen if it ever grows important enough to global affect farm economics. It is a dreadful mishmash of science-avoiding, chemical-avoiding excuses dressed up as vital to virtue signallers. Like your air-head comment that started this reply. Geoff.


Just remember that the use of Night soil is a form of organic farming.


Organic farming: feeding dozens from land which could feed thousands.


Why are you so afraid of chemicals?


Not if you are hungry. Wisely used chemicals increase yields. And you need to use the soil you have, so some will need to add minerals.
Idealism, eh?

old construction worker

Was this another computer model study?


From the study, at
Although these data indicate that [CO2] affects nutrient composition, the impact of these qualitative changes on health will vary as a function of rice consumed relative to the total caloric intake. Previous calculations of the impact of rising CO2 on human nutrition relied on Food and Agriculture Organization (FAO) food balance sheets combined with Monte Carlo simulations run on the range of projected declines of zinc, protein, and iron.


As long as it still snaps crackles and pops I’m good.


The US grows and exports a heck of a lot of rice. I see the fields and processing elevators in S. Missouri, Arkansas, and Texas frequently. Significant export for the US. I suspect that next some moron will start complaining about the fact they burn the stubble off once the crop is harvested.


Glancing through the full paper and methods description, it appears (unless I’ve missed something) that all the analyses were performed on uncooked rice. What impact does cooking rice have on its nutritional content?

Peta of Newark

1. Rice is nutrient free mush. Only desperate folks on the verge of total starvation eat it
2. Even miniscule amounts of cow, sheep, pig or Bambi will get you all your mineral needs – IF you don’t throw the best bits away, as is current practice. (Blood, offal and fat)
3. Growing rice in paddy fields (how many folks here think that that is an essential) is a massive waste of water AND yield potential. Dry rice production grows 3,4 or 5 times more stuff, uses easily 50% less water AND saves young women (typically) weeks and months of back breaking slog.
4. Give them folks a tractor and a steel plough. Use less water, grow more rice, save the women from premature old age AND enable the rice ‘straw’ to be incorporated into the soil – improving fertility, water retention AND, captures carbon. Paddy fielding is ONLY a method of weed control. Rice is an ordinary grass, it is not a ‘wetland’ plant – contrary to what you were told at primary school and have never questioned. ??
5. Cant recall where or when but read about a fairly self-contained tribe somewhere on this planet that fed themselves with rice. If they had a ‘good year’, they would actually force-feed themselves with the excess rice. This caused them to poo an awful lot (the desired result) and they knew that putting the humanure onto their rice fields caused ever more rice to grow. What do we imagine became of those folks? Did diabetes finish them, did they poison themselves either with bacteria or by acidifying their soil and hence mobilising metal toxins. Aluminium becomes mobile at pH 5.5 or lower – it is unpleasant stuff and a VERY common part of dirt.
5.1 The Romans knew all about manure and used it to improve their crops. Great speeches and pronouncements were made on the subject of Agriculture and its modern and improving practice. They turned Southern Europe and North Africa from fields, forests and gardens into desert.
6. Wheat, corn & potatoes are the same as rice – nutrient free mush. Of the 20 or so million folks in the UK who work and actually contribute (millions work in Government but they don’t count as contributors, opposite really) – those 20 million pay £5,000 per year to fund the National Health Service (NHS). Folks in the US pay 18% of their gross salaries. A report out today on the BBC News say that the NHS will need an extra £2,000 per year from those folks inside the next 15 years. Why? Is it because they are all fat lazy can’t-be-asred slobs who don’t go to a gym? Really? Is that what you, informed by doctors and media alike, actually think?
Question: Why do supposedly healthy people (never better apparently) walk into doctor’s office, surgeries, pharmacies and hospitals and spend so much money?

Geoff Sherrington

Why not read a good book about plant and animal nutrition in preference to bursting into print with rumour and wrong science?
The field is adequately understood and does not need a help along from layman conjecture. Geoff


I can’t imagine enjoying the General Tso’s chicken I had for dinner last night without it being over rice.
We humans adapt to the diets we have. Those in the far east adapted to get the most out of the staple rice. We in the west adapted to other grains the most common being wheat and most often served in the form of breads, to get the most out of them.
When westerners became POWs and slave laborers of the Japanese in WW II it was not just the lack of food, ill treatment, and lack of medical care that caused their debilitation, it was the type of food. On average US POWs of the Japanese that survived lived more than 10 years less than those that had been held by the Germans. There were several factors that contribute to that statistic but diet is part of it.


Contrary to Peta’s ramble, carbohydrate IS a required nutrient.
Animal feeds are formulated taking energy into account (ie, ensuring they have sufficient) and most of that energy comes from carbohydrate. In fact, grains are considered/discussed as ‘energy’, and soybeans, pulses etc are considered/discussed as ‘protein’.
You are making the common mistake of viewin nutrition from the affluent western human viewpoint.


I’m a wheat rancher, but still like rice. It has two of the four essential amino acids, ie those of the 20 which humans can’t make on our own. Combined with legumes, it’s possible to make complete protein, as so many billions of people have done for so many thousands of years.
Rice also contains other vital nutrients such as vitamins.


Eat golden rice. enjoy


Just don’t eat yellow snow.

Dennis Bird
Original Mike M

This whole nonsense is easy to shut down with one question – “What is worse? Slightly less vitamins or slightly more war?”


Disgraceful science publication. There is NO MENTION of the total yields anywhere in that paper. This paper is nothing but a funding fishing exercise.
This is another example of disgraceful scientific reporting: Even if it is not the principle area of investigation there should be mention of the most important parameter in terms of nutrition in marginally food deficient societies.
Total yield is almost certainly increased, AND it also provides the most likely explanation for the decline in the nutrients they measured (the decline characterised as a complicated chemical mystery in their report) … the decline in the vitamins, minerals and protein is simply dilution with the extra carbohydrate produced.
In a hungry country, the grateful consumer simply needs to eat a bigger portion of the bigger crop to get his vitamins, and gets to digest them with the comfort of a full stomach.
This below shows how this should be reported:
Pingale et al. (2017) grew rice and maize for two growing seasons under ambient (395 ppm) and enriched (550 ppm) CO2 using Free-air CO2 Enrichment (FACE) technology at the Indian Agricultural Research Institute in New Delhi, India.
…. elevated CO2 positively influenced the growth and productivity of both crops. Plant growth and yield parameters such as leaf area, stem dry weight, panicle dry weight, cob dry weight and grain number per cob were all significantly increased under elevated CO2. And the end result of these several enhancements was a CO2-induced increase in both rice and maize grain yield. As shown in the figure below, for the 2011-12 and 2012-13 growing seasons, elevated CO2 stimulated rice grain yields by 14 and 16.2 percent and maize yields by 13.3 and 13.8, respectively, which increases were statistically significant.

The change in plant content is true for many environmental changes, such as… irrigations. It should be expected with irrigations that for the same plants mass to have less nutrients/vitamins and more water. Nothing surprising or unexpected, isn’t it? Nevertheless, they don’t advocate avoiding irrigations and using only deserts for plant growth, to avoid the dihydrogen monoxide poisonous pollutant…

Joel Snider

Seriously, why would the Guardian even care about nutrition – last article from them, they were siding with Thanos in the Infinity War – that whole ‘human existence is unsustainable’-thing.

Matt G

The biggest flaw in this study is not taking into account nutrients in the soil because each crop reduces them. The higher the crop yields the more nutrients from the soil it takes, so if they don’t replace the nutrients in the soil, the crop will contain less nutrients even with the same CO2 levels. This factor has nothing to do with CO2 except that larger yields take more nutrients out. Replace the nutrients in the soil so how does this effect crops with higher yields? It is why farmers use crop rotations and nitrates especially need replacing.

Gary Pearse

The Petri-dish worldview ^тм that 97% of biologists have makes them a cookie cutter educational product of their ideological schooling. Biological training is devoid of the skills needed to envision likely futures because of a lack of an awareness of human ingenuity that alters futures as required. Yet a prepondrance of scarey futures are produced by linear thinking biologists. It’s a calling. An engineer’s view by contrast is underpinned by a problem solving mindset.
“Sustainability”, “planetary carrying capacity”, “limits to growth” are all poppycock failed scienciogy and are the hallmark of this type of shallow, zero sum ‘thought’. And, like the screen play “Groundhog day” they are destined to repeat themselves ad nauseum. The end is nigh theme has been repeated over and over again since Malthus in the latter days of the 18th Century (we were to have been buried in horse dung up to the third floor in all the major cities a century into his scenario – I kid you not!).
Pearse’s Axiom: I have come to understand, on energy-at-our-command considerations alone, supported by the abysmal failures of predictions made to the effect, that an enduring planet wide harm from manmade global disaster is not possible! Period! All ‘harm’ done by humans to the planet is axiomatically local and temporary and hardly a miniscule proportion of what a moderate bolide collision has done. Even traces of a large one show it, too, to be disappointingly temporary.
Even assuming enough ill intent could be marshalled – no issue. It is safe to disregard all such prognostications of even modest harm until it is unequivocal some action is necessary. Then, like always, the doers will take care of it.
Is the “97% of biologists”, the “97% of climate worriers” and the “97% of sheep in the USSR” a match for the 3% of dissidents? I leave the answer for homework.

Gary Pearse

Please mods, the piece is benign and on point.8