The short version, if I remember it correctly: Plants open and close their pores ("stomata") to balance the need to get CO_2 from the air with the need to conserve water, which easily evaporates away and then needs to be replenished through the roots. If we give plants lots of CO_2, they will close their pores to prevent water loss (because who knows when it'll next rain, right?). But the micronutrients, including the N required to make proteins, come from the ground – so the plants' own mechanism to minimize having to rely on water from the ground results in the plant accumulating fewer micronutrients.
I think it's great that we have people researching this. However, what worries me are not the results but how we are going to deal with them. As a species we have to cope with the fact that the climate is changing, we won't reverse that so easily. This is a fact. I'd rather talk about how to overcome the obstacles exposed by this study not only the mere fact that our food is changing "for the worse". Finally, I believe for many parts of the world I suppose it isn't as bad as portrait to have a higher carbohydrate share in their meals.
>Finally, I believe for many parts of the world I suppose it isn't as bad as portrait to have a higher carbohydrate share in their meals.
Actually this is a big problem eg in South Africa, which has very high obesity rates. For most poor people a meal is refined maize porridge, often with a coco-cola, or bread and a coke. It’s imperative that people get access to cheap, quality protein, it could be something like lentils, beans ...
I would expect any effect of atmospheric CO2 concentration on a person's carbohydrate intake to be totally dominated by food preference / availability / choice and by selective breeding of plants used for food.
That's my main gripe with the article, too. It's really interesting biologically, but it doesn't really talk about the effect size. The influence of selective breeding is even mentioned in the article, but without explaining the relative influences.
> The data we have, which look at how plants would respond to the kind of CO2 concentrations we may see in our lifetimes, show these important minerals drop by 8 percent, on average. The same conditions have been shown to drive down the protein content of C3 crops, in some cases significantly, with wheat and rice dropping 6 percent and 8 percent, respectively.
I had the same gripe. 6%-8% change doesn't quite seem insignificant, but this is under CO2 concentrations that "we may see in our lifetime". So how much more CO2 were these plants exposed to than the controls, and how strong is that "may"?
As far as I understand the article it states that the share of carbs is increasing. That food is lacking other nutrients seems to man made as well but the underlying reason is not climate change but agricultural methods that have changed
It's worth noting that there's an opposite force in play - as poor countries get richer (or, for the first world, got richer a century or two ago) the typical worker's meal goes from almost entirely staple crops (wheat, corn, rice, etc) to having these crops as a side dish to a relatively protein-heavy animal product (meat, eggs, dairy).
If you e.g. potatoes+bread based diet with meat once a week transforms into meat at every meal, then the total diet has more protein even if the potatoes and wheat don't have as much protein as they used to.
GMO, would people like it or not, will be a solution.
Stuff like Soylent might also be a solution. I've heard people say that the lack of taste in food might make their meal much less appreciable, but let's be honest, if it's a matter or health, enjoying a meal might become a luxury.
FWIW, I consider the present state of such powders to be highly deficient, but I do believe that in time and in theory they could serve as a permanent replacement for food. At minimum, the current deficiencies have to do with phytonutrients and various fibers.
Yeah, and by the year 2000, we'll all be eating meals in capsule form. Oh wait, what's this? It's your 1950's techno-utopia calling. It said it's never coming. Something, something, more like mad max.
The article mentions a connection to obesity. "To what degree would a shift in the food system contribute to that? We can't really say.” I really wonder if this already a part of the worldwide obesity crisis.
More carbs/nutrition in the food leads to more calories/nutrition. So, on average, you would have to consume more calories to get all required macro and micro nutritions. The effect doesn't have to be big. Just a few more percent in calories consumed can lead to a large weight gain, compounded over many years.
I'm likely missing some important pieces on nutrition science but it's interesting to play with the numbers. The article says that the amount of 'important minerals' might drop by 8% in the future. Let's say it has already dropped by 5%. In order to get the same amount of minerals today, you have to eat about 5% more of the same food leading to about 5% more consumed calories. Let's say you would keep your current weight at 2500 kcal/day, but now you consume an extra 150 kcal/day. Assuming a weight gain of 1 kg/7700 kcal, this would lead to a weight gain of 150 kcal/day x 1 kg/7700 kcal x 365 days/year = 7 kg/year. Hence, a 1.65 m tall person starting with a weight of 60 kg (BMI = 22, normal weight) would be considered obese within a mere 3 years (81 kg, BMI = 30).
Of course, the increase in CO2 and subsequent drop in nutritions with a magnitude of 5% takes place over a longer time span than 3 years. But I still find it interesting, that apparently this effect could explain an enormous amount of the obesity puzzle. If, hypothetically, humans wouldn't have changed the composition of their diet or calorie expenditure at all, but their bodies are tuned to maintain a fixed amount of nutritions, the small drop in nutrition content alone could apparently explain a worldwide increase in obesity.
"But I still find it interesting, that apparently this effect could explain an enormous amount of the obesity puzzle. If, hypothetically, humans wouldn't have changed the composition of their diet or calorie expenditure at all, but their bodies are tuned to maintain a fixed amount of nutritions, the small drop in nutrition content alone could apparently explain a worldwide increase in obesity."
This effect is easily explained by the "food pyramid" theory of nutrition, which emphasizes carbs as the major food source. It seems very clear that this is wrong, and the healthiest diet includes substantially more fat and protein. The other increasingly missing ingredient for a leaner population is called "exercise".
A viewpoint I argued for a decade or more ago, without any result - agribusiness has also been busy reducing nutrient content and increasing growth; but they don't want much attention to the possible results.
Most, if not all, of these micronutrients are very common materials - zinc, iron and so on. This research does imply that supplements are becoming more important, and we should do more research into making supplements more effective and inexpensive.
It's also probably worthwhile to research if additional fertilization can offset this effect.
For the wealthy, indoor organic vegetables grown in a 280 PPM CO2 environment might become a new luxury item. There have been some interesting developments in high-density indoor farming using LED lighting.
The problem ought to affect all life, not just humans, I would expect. The article barely touched on other animals.
Have people looked at how the changes affect other animals -- wild or domesticated? Does it affect us through animals we eat? If so, does the effect compound?
Considering how much we supplement our nutrient intake through eating processed foods (e.g. enriched flour) I doubt a human study would even be possible.
Pollan's point is that there's more to nutrition than carbs and protein. It was already established that the green revolution (which ultimately was about turning fossil fuels into food) resulted in food with more carbs and less everything else. Global warming apparently is doing the same.
An 8% decline is not a "collapse." Also, this could be considered a feature, not a bug, that crops can be produced with less fertilizer, that zinc and iron is still in the soil for the following years. Nutritionists always say that eating a balanced diet provides people with far more of the essential minerals and vitamins than we actually need.
So an alternative headline: "Climate change allows crops to be produced more abundantly and with less fertilizer and added micronutrients, while retaining more than 90% of their nutrients"
It may not be a collapse for people who get to choose what they eat, how much they eat, when they eat and how often they eat. But this certainly has a huge impact on the overall human population, where the poorer classes stand at a huge disadvantage with an 8% drop in nutritive value and cannot get supplements and other aids. The existing research and initiatives to fortify staple foods will have to intensify and become more widespread. That's easier said than done.
If you are a wealthy (compared to the average world) western person, they this is not a big issue as you can compensate. If you depend entirely on locally grown plants (most of the world) with barely enough to eat less nutrition is a big problem.
Very interesting issue although I would say as it relates to humans, our diets are already so poor and artificial that changing eating habits and what we put in our food could likely balance out some of this nutrient loss in the actual plants.
This is an interesting theoretical idea. All Science is great.
But today, today we have massive issues with the 3rd world poor with micro-nutrient deficiencies.
This makes no difference, wow 200 million people goes to 240 million people sometime in the far future if we do nothing.
How about we solve the real issue, micro-nutrients in the 3rd world poor instead.
It's not sexy like, big scary global warming. And it has simple boring solutions.
But today we can save lives cheaply and it creates long term solutions (lacking micro-nutrients in children reduces IQ, stopping this happening help pulls people out of poverty permanently)
Frankly if you are worried about this, then your priorities/morals are shot.
We can solve this issue today at cost Y. Or we can pay 10*Y to reduce 1/10 of the issue in 50-70 years time.
This thesis,'if true' is a small part of the nutrient problem, it won't even touch the poorest of the poor in the western world for instance. Because once you pull people a little above poverty nutrients in foods are meaningless.
Micronutrient deficiencies are solvable today at 'low' cost (~zero cost compared to the global warming issue)
They are considered perhaps the leading problem in the world today.
Whilst it's not true that the world can only progress on one issue at a time, I think that there's a fair point to make about prioritization. You as an individual can only focus or fund so many issues and we do have to make choices on what to focus, eg. first world identity politics vs wealth inequality.
The short version, if I remember it correctly: Plants open and close their pores ("stomata") to balance the need to get CO_2 from the air with the need to conserve water, which easily evaporates away and then needs to be replenished through the roots. If we give plants lots of CO_2, they will close their pores to prevent water loss (because who knows when it'll next rain, right?). But the micronutrients, including the N required to make proteins, come from the ground – so the plants' own mechanism to minimize having to rely on water from the ground results in the plant accumulating fewer micronutrients.