How can we feed 20 billion people

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In summary: Interesting, that we're only 11 years away from the 300th anniversary of the publication of A Modest Proposal [wiki].Still haven't read it.
  • #36
stefan r said:
It is quite clear that eating beef lowers your life expectancy.

Please give some specific references. My understanding is that studies in this area don't all show this result, plus they are almost all studies of eating meat from animals raised in the unhealthy ways I described earlier.

stefan r said:
It is highly unlikely that red meat was a primary dietary source for evolving humans.

If your definition of "red meat" is beef, then yes, of course this is true, since most of human evolution took place before cattle were domesticated and raised for meat.

However, there is plenty of evidence that humans hunted big game and that the meat from that game was a significant food source for most of human evolution. See, for example, here:

https://www.nature.com/scitable/knowledge/library/evidence-for-meat-eating-by-early-humans-103874273

stefan r said:
There is no way you can have 10 billion people on Earth consuming free range beef as a major component of their diets.

This is probably true (and gets us back on the thread topic, which is good). Free range beef isn't a major component of the diet of most of Earth's people now.
 
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  • #37
I find this website to be an excellent source of actual data on food production. I've pulled out one of the more interesting graphs below. Since 1961, we can produce the same amount of food on one third as much land. It's hard to look at these charts and conclude that we will have difficulty feeding the world in 2050.
ourworldindata_land-per-crop-pin-750x525.png
 

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  • #38
phyzguy said:
I find this website to be an excellent source of actual data on food production. I've pulled out one of the more interesting graphs below. Since 1961, we can produce the same amount of food on one third as much land. It's hard to look at these charts and conclude that we will have difficulty feeding the world in 2050.
There have been substantial reductions in the percentage of grains that become seed.

The amount of petroleum used per calorie of food has the opposite slope:
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  • #39
stefan r said:
There have been substantial reductions in the percentage of grains that become seed.

The amount of petroleum used per calorie of food has the opposite slope:
View attachment 232232
Did you attach the wrong graph? I don't see anything about petroleum use. In either case, it is tough for me to see what your point is.
 
  • #40
russ_watters said:
Did you attach the wrong graph? I don't see anything about petroleum use. In either case, it is tough for me to see what your point is.
Sorry, nitrates are produced by petroleum.
I'm confident there are more engines burning it too. Potasium, topsoil, and water are all concerns.
 
  • #41
stefan r said:
Sorry, nitrates are produced by petroleum.
I'm confident there are more engines burning it too.
The nitrates graph is not per calorie (none of the graphs are).

Do you actually have per calorie graphs? I would actually be interested in seeing them. What I would expect is that when any new technology is incorporated it would have an initial period where its intensity rises until fully incorporated, then drops as efficiency improves. In the west we've seen this with basic energy usage intensity, which peaked in the '70s and has dropped since. The tough part is that since developed countries are still developing, their usage hasn't peaked yet. I suspect the same applies to energy and resources specifically used for farming.

10 years ago I was pretty concerned about the world's long term energy prospects, but I'm not anymore. We have the ability to provide most of the world's energy cleanly and cheaply; we just have to decide to do it. But until then, we have plenty of fossil fuel to make it through this century.
 
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  • #42
russ_watters said:
The nitrates graph is not per calorie (none of the graphs are).

Do you actually have per calorie graphs? ...

I can't find one, but I have had enough of agriculture reading for a least a few weeks.

I did find this from USDA, paragraph 2 of conclusion:
The majority of energy consumed in agriculture is in the indirect form used to manufacture fertilizer, followed by diesel, electricity, and natural gas.

A graph of primary energy consumed per unit of dietary energy consumed would be relatively flat. At least compared to either the graph of yield per acre or the graph of fertilizer consumption.
Should also include erosion of topsoil. The same acre may not continue providing the high yields.

The slope of the graph should change depending on which data you use. Do you include things like food thrown away (actually not sure if that is up or down in USA). Does composted food count as thrown away and/or does the energy get counted in the garden vegetable. Some food additives like Splenda give 0 dietary calories but clearly must consume more energy to produce than glucose. Is the energy consumed building and maintaining roads included in agriculture? You would usually count that as transportation but if trucks are transporting corn then it is part of the energy in food at the grocery store.

I'm certainly not recommending hoarding food or panicking. The food supply problems are easily solved by people becoming vegetarians. There is also little point in talking about forcing anyone to become vegetarian. We could just stop subsidizing meat/dairy production. Doing nothing as a country really does solve most of the problem in the USA. [by doing nothing I mean taking action on a bill that removes all federal and state subsidies] If people on the left cherish state food subsidies we could still solve the problem by subsidizing healthy vegetarian foods instead of poisoning people. There may be no need to tax people who consume beef the way cigarettes are taxed. A free market would cause a major shift in consumption.

Cricket protein is nearly an order of magnitude more efficient than beef. If you really do not want to go vegan there is that option. There is a lot of good vegan food so personally I have not found any reason to look for an alternative.
 
  • #43
stefan r said:
I can't find one, but I have had enough of agriculture reading for a least a few weeks.
Fair enough.
The food supply problems are easily solved by people becoming vegetarians.
Given that the consensus here seems to be that there is no food supply problem, this "solution" looks moot to me.
 
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  • #44
This thread is not about science or engineering problems, those solutions have been found a long time ago. This is about human stupidity and error propagation.
 
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  • #45
BillTre said:
A few years ago I tried about three different kinds of veggie hamburger.

None of them were very like hamburger IMHO.
Perhaps there are better now, if so what are some examples.

I have tried the "Impossible Burger," which uses heme produced recombinantly in yeast to make its plant-based patties taste more like meat, and found it to taste pretty good.

PeterDonis said:
Please give some specific references. My understanding is that studies in this area don't all show this result, plus they are almost all studies of eating meat from animals raised in the unhealthy ways I described earlier.

Many regulatory bodies classify consumption of red meat as a probable contributor to cancer (colorectal cancer specifically, though there is some evidence it could affect other cancers). The effect is somewhat small, so completely eliminating red meat from one's diet is probably not necessary, but most sources recommend limiting the consumption of red meats and processed meats:
https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(15)00444-1/fulltext
http://www.who.int/features/qa/cancer-red-meat/en/
https://www.wcrf.org/dietandcancer/exposures/meat-fish-dairy
https://www.cancer.org/healthy/eat-...sical-activity-cancer-prevention/summary.html

Of course, these conclusions are based off of observational studies, so nothing can be really be proven conclusively, especially considering the difficulty of performing a randomized controlled trial. Still, the recommendations reflect the preponderance of the best available scientific evidence. In light of these studies, I have certainly made an effort to reduce my consumption of red meats and processed meats.

Some hypothesize that cooking heme could potentially contribute to the carcinogenicity of red meat, so if that's true, the Impossible Burgers mentioned above may not offer as much of a health benefit (at least with regard to cancer risk) as other meat substitutes.
 
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  • #46
cronxeh said:
This thread is not about science or engineering problems, those solutions have been found a long time ago. This is about human stupidity and error propagation.

First chill out man - we are discovering new things all the time and engineering/technology is progressing at an incredible pace. I personally am not worried about many of the things you hear in the popular media along the lines of we are all doomed because while many problems are solved those solutions are getting even better - we just need to ensure the public understands science/engineering better. That's where I think this forum is very useful in people understanding the actual science and we must stick to the scientific method.

Thanks
Bill
 
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  • #47
Methinks this thread has run its course. Moderators?
 
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  • #48
phyzguy said:
Methinks this thread has run its course. Moderators?
Wegrees.

Thread locked.
 
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