Irrigating more U.S. crops by mid-century will be worth it, researchers say
phys.org
phys.org
Can anyone link me to resources that go into more detail about this? I feel like I keep coming across conflicting projections: 1) That a warmer climate is a wetter climate, but 2) There will be more droughts.
I'm not trying to argue with either of these, I just want to understand what I'm missing — to try to fill in the gaps of understanding.
> higher temperatures drives increased evaporation which leads to increased droughts
Certain types of vegetation work better in higher temperatures. Remove vegetation altogether, and the combination of higher temperatures, wind, and rain will transform the land into deserts. Preserve old-growth forests, and they will remain lush, green, and wet regardless of temperature variations.
> the evaporated water in the atmosphere has to come back down again, which it will tend to do in a great big splash
Atmospheric rivers are interesting.
https://en.wikipedia.org/wiki/Atmospheric_river
> don’t really penetrate deep enough into the soil to alleviate the increased evaporation (too much too fast)
That depends again largely on the type of vegetation growing there. Forests and wetlands can capture the rain and allow it to seep, while pastures and corn fields will retain very little, which can lead to soil erosion and droughts / water shortages.
https://archive.ipcc.ch/news_and_events/docs/SBSTA-44/Sbsta_...
We cut down a tree, and not much changes (except for the sound, maybe :). We cut down a forest, and things still seem okay. We replace many forests with pastures, and everything appears fine. We prevent forests from regrowing, and everything continues to function as expected.
However, if we continue this pattern for a long time, eventually the forests reach a breaking point. They lose their ability to retain water and generate new rain, causing them to dry out and cease sending moisture further inland. With even less rainfall in those areas, the forests dry up and die out, worsening the problem.
https://phys.org/news/2022-08-global-forest-area-capita-decr...
Over the past 60 years, the global forest area has declined by 81.7 million hectares, a loss that contributed to the more than 60% decline in global forest area per capita.
https://www.ucsusa.org/resources/whats-driving-deforestation
Just four commodities—beef, soy (for animal feed), palm oil, and wood products—drive the majority of tropical deforestation.
So we can expect some areas to be much wetter and some areas to be much drier and that areas will have a higher temperature variance (colder in winter as winds from Arctic north are stronger to blow colder air deeper south etc.)
Here in Colorado we've had two summers of historically high humidity. Last year humidity rolled in, the prairie greened, and then later the rains came. This year, the prairie has been green all summer thanks to rain and humidity. We've never had humidity like this so I never realized how important humidity was for plant growth. I had always given rain more weight than it deserved.
Zaitchik, B.F., Rodell, M., Biasutti, M. and Seneviratne, S.I., 2023. Wetting and drying trends under climate change. Nature Water, pp.1-12.
Climate change is expected to alter global water regimes significantly, although there is disagreement on regional specifics and uncertainty in precipitation models (Trenberth et al., 2014). Precipitation and runoff modeling is complicated by incomplete historical field measurements, an inability to reproduce existing regional drying patterns, sensitivity to the choice of initial conditions for sea surface temperature, and poor aerosol forcing accuracy among other challenges (Dai, 2013).
While these and other uncertainties, such as the net effects of vegetation feedback and CO2 levels on soil moisture are acknowledged by the authors, the most recent climate model ensemble, CMIP6, forecasts further whole year drying in western North America, Central America, Europe and the Mediterranean, the Amazon, Southern Africa, Southeast Asia and Australia (Cook et al., 2020). This general aridification forecast is not universally supported, and other researchers believe that since the paleoclimate record demonstrates that warmer paleoclimates are also wetter, it is more likely that the vegetation response modeling in CMIP6 is decisively incorrect, and that it is more likely that overall precipitation will increase while intra-year seasonal variability also increases under climate change (Zaitchik et al., 2023).
The combination of increased temperatures, more variable soil moisture and higher CO2 levels make forecasting future crop yield responses under climate change challenging and response results from experimental simulation and statistical modeling vary widely (Jones et al., 2014). For example, in a well-controlled growth chamber study of wheat response under RCP8.5 temperature and CO2 levels, crop lifecycle shorted appreciably but yields were not affected and one of the study’s cultivars had approximately 25% higher yield under simulated climate change (Sabella et al. 2020). Conversely, a meta-analysis of 91 statistical studies of crop response showed a mildly negative response for most crops/climate combinations to climate, but the variance of results across the included studies was extremely high (Challinor et al. 2014).
While future water regimes are uncertain, there is high certainty about how current water regimes compare to historical averages. With some regional exceptions, the last hundred and fifty years has been a well-watered period compared to the millennial average. From 951CE to 1500CE, the North American continent experienced four major multi-decadal droughts, and the early 19th century was a period of recurring severe drought in the America West (Cook et al., 2007). During the last millennium, Europe experienced two exceptional periods of multi-decadal dryness, from 1400 to 1480CE and from 1770 to 1840CE (the Sporer and Dalton minima respectively) (Ionita et al., 2021).
More recently, Europe experienced significant agricultural drought in 2003, 2015 and 2018 and recent tree-ring research indicates that drought severity in 2015-2018 is anomalous compared to a baseline of 1600CE to present (Freund et al., 2023). Globally, drought frequency has increased in China and India; and recent droughts in the African Sahel are historically unprecedented in duration and frequency (Mishra and Singh, 2010). However, to date, the overall magnitude of the increase in drought severity, as measured by the Palmer Drought Severity Index (PDSI: range -10 to +10), has been small. In North America, for example, there has been a mean -0.3 decrease in the PDSI vs. a 1950-1970 baseline, compared to the historical overall range of approximately -4 to +4 (Trenberth et al., 2014).
https://www.amazon.co.uk/Drought-Interdisciplinary-Perspecti...
There are alternatives that are shown to both provide enough calories, sequester more carbon than created, and steward land to mimic the natures natural cycles.
https://whiteoakpastures.com/pages/environmental-sustainabil... https://www.goodreads.com/book/show/50249804-sacred-cow
There's so much more in play than calories when it comes to our relationship to food and the natural world.
You seem to have frame it as “land destroying plant only farming” vs “animal and land friendly mixed use” which seems like a false dichotomy. What’s wrong with plant based + rotating crops and sustainable use?
(I eat meat, fwiw)
Plant -> Person
Plant -> Farm Animal -> Human
Edit: My goal is to explain the basics of the argument that the parent comment was unfamiliar with, not to advocate.
You’re saying animals are extra steps and I’m saying both plant alone or mixed use could be sustainable?
There are worrying signs. Maybe the largest is the amount of deforestation happening to support the growing beef industry and feedstock for animal agriculture [0].
[0] https://www.worldwildlife.org/magazine/issues/summer-2018/ar...
The effect of this on your diagrams is in diagram 2, with the intermediate farm animal, there are many situations in that scenario where the calories from those plants would be entirely lost, not simply rerouted losslessly to human consumption.
It seems to me that there are many grassy hills that cannot be farmed using tractors and to farm them using hand tools is too labor-intensive.
My knowledge comes from exposure to the agricultural industry. You might be able to find some animals grazing on a grassy hill, but that doesn't scale. In addition, most NA climates don't support year long grazing.
This fundamentally ignores a bunch of realities around land quality, thermodynamics, and nutrition bio-availability.
Generally what's wrong with (everything in the nutrtition and fitness space) that the terms are overloaded to mean whatever it is the person speaking it deems at the time. Example: Paul Saladino (carnivoreMD) touts an animal based diet. Then when you dig into what he really recommends for eating is animal products + fruits and plants that have limited defense chemicals that can cause (for some people) disruptions in their life.
The position i advocate for is regenerative agriculture where we sequester more carbon by using the animals to mimic the natural grazing cycles and provide fertilizer for plants. This is incredibly important because in order to produce crop yields like we do, we require massive amounts of fertilizer, which requires petroleum inputs to create which gets us back to thermodynamics. To do crop rotation appropriately in a sustainable way, you need ruminant animals.
It's a complex topic that I invite everyone to spend some time taking a look at because there's really big money in meat production as well as artificial meat production that have a vested interest in winning you over.
Also lets not pretend that 900 million cattle [1] is a boon to biodiversity. In Point Reyes, Tule Elk are being edged out by cattle farmers, for example [2]:
Now she learned that a free-roaming herd of elk had been wandering onto park ranchlands, upsetting cattle ranchers who run cows on leases that cover a third of the seashore’s acreage. The ranchers wanted the elk fenced away from their cows. Oppenheim went home that night and plunged down an internet rabbit hole, reading warnings from environmental groups that the National Park Service (NPS), which manages Point Reyes National Seashore, might shoot the offending animals.
[1] https://www.statista.com/statistics/263979/global-cattle-pop...
[2] https://www.hcn.org/articles/wildlife-the-battle-over-point-...
Small numbers of tule elk in Point Reyes have tested positive for Mycobacterium avium subspecies paratuberculosis or "MAP", a wasting disease known as Johne's Disease. The bacteria was apparently transmitted by dairy cattle or spraying of cattle manure on pasturelands. In 2016 more tule elk tested positive after being euthanized so that their gut tissue could be analyzed. Cattle transmitted the disease to the Tomales Point elk herd shortly after they were first established there in 1978.
https://en.wikipedia.org/wiki/Tule_elk#Historic_range_and_cu...
It's quite clear that you can live a healthy life with most calories from plants in some capacity. It's also quite clear that you can do the same with animals. Where it gets dicey is when we get into the specifics about farming methodologies, sustainability, and ethics.
This is why i linked to white-oak pastures to give an example of regenerative agriculture practices that are proven to work. What's important is that when we talk about animal consumption that there's a ton of sins by the cattle industry specifically that need to be corrected. Moving to a regenerative agriculture method will lower their profits quite a bit, and they often find it helps their message to misdirect towards the "plant-based" (overloaded term) crowd..
The current battle in Montana between Bison restoration and ranchers versus the cattle industry is a great example [1][2] of how cattle industry behaves. Bison restoration and Bison ranching has taken off in Montana and Idaho. There is abig push to try and restore the natural grasslands and grass species that the Bison grazed on to improve the ecology of the area as a whole. Cattle are not compatible with that plan (imo) in Montana. However, bison are ruminant animals which are the linchpins for keeping the soil healthy enough to grow crop without large petroleum inputs (fertilizer). So 900 million cattle may not be a boon on their own, but if we put environment appropriate ruminants (goats, sheep etc) in the same places we can still perform regenerative agriculture.
This topic leans towards heavy nerd snipes because there's so many rabbit holes to go down. For example:
of the land that is used for grazing animals, how much of that is suitable for farming the big three (wheat, corn, soy)?
Assume that every human is capable of getting enough calories to survive: Are they getting enough bio-available nutrition to meet the minimum needs? What about to perform closer to an optimum of mental and physical capacity?
What does it really mean to be nutrient dense? Are we actually able to extract all the nutrients? What about if we started consuming organs again instead of just ribeyes?
[1]https://apnews.com/article/health-environment-and-nature-bus... [2]http://america.aljazeera.com/articles/2014/2/19/yellowstone-...
Sure, but we're totally ignoring water rights here. If your state has Appropriative rights, you can't just start watering fields without the government getting involved. In that case, you can't actually get new rights anymore, which has created a new market. I had to purchase mine from a winery nearly a decade ago and I STILL don't officially have rights yet.
> Last month, record low water levels in the Mississippi River backed up nearly 3,000 barges — the equivalent of 210,000 container trucks — on America’s most important inland waterway. Despite frantic dredging, farmers could move only half the corn they’d shipped the same time last year. Deliveries of fuel, coal, industrial chemicals and building materials were similarly delayed throughout the nation’s heartland.
> This critical river and its tributaries — responsible for transporting more than $17 billion worth of farm products and 60 percent of all U.S. corn and soybean exports annually — has been stricken by drought since September, amid a time of global grain shortage and soaring food prices. While water levels will recover modestly this week, thanks to some upstream rain and snow, the long-term forecast remains dry.
Your quote does nothing to suggest that expanded irrigation would make a dent in the river level, be it high or low.
Define drought for me.
I feel like you are playing dumb here. No amount of agriculture will meaningfully lower the river level. That's the point in question. That's what I'm saying.
> The Lower Mississippi River Basin (LMRB) is an internationally-important region of intensive agricultural crop production that relies heavily on the underlying Mississippi River Valley Alluvial Aquifer (MRVAA) for irrigation. Extensive irrigation coupled with the region’s geology have led to significant aquifer decline.
https://www.fs.usda.gov/research/news/highlights/mitigating-...
> Groundwater depletion is a serious concern in Mississippi and worldwide. Agricultural crop production in the Mississippi Delta requires irrigation, and that water use has led to severe groundwater depletion. Converting crop land to forests through afforestation can conserve water resources, improve water quality, and mitigate river floods.
Aquifer != river. The overuse of aquifers is common knowledge. The commenter is making a narrow point about the river. I would like to see a response directly speaking to their concern, not something that is adjacent and common knowledge.
> Since major groundwater pumping began in the late 1940s, overdraft from the High Plains Aquifer has amounted to 332,000,000 acre-feet (410 km3), 85% of the volume of Lake Erie. [1]
> The Mississippi River passes more than 240 million acre-feet annually at the proposed point of diversion, 30 miles south of Cairo, Ill. During the current flooding, more than 4 million acre-feet per day are flowing at that spot… [2]
The water in the Mississippi river could each year replace all 80 years of overpumping of the aquifer. So with 1-2% water diversion (like I said, not exhausting the river), you could easily substitute that volumetrically. For 5% you could massively irrigate the midwest.
These are truly massive rivers. People in the west don't understand how enormous they are compared to the Colorado and other western rivers.
[1] https://en.wikipedia.org/wiki/Ogallala_Aquifer#:~:text=Since.... [2] https://coyotegulch.blog/2011/05/19/pipeline-from-the-missis...
> Our results suggest that there is relatively little overlap between where there is enough water to fully irrigate crops without placing additional stress on water resources and where farmers can expect the investment in irrigation to pay for itself over the long term
What won't we do for those 18% of calories.
If we preferred to reforest and rewild those pastures instead, we could stop the droughts and allow biodiversity to rebound.
We already get 82% calories and 63% proteins from plants, but animal agriculture takes 80-90% of all agriculture lands, and is a leading driver of deforestation, biodiversity loss and droughts.
https://talkveganto.me/en/facts/suitable-for-all/
We don't need to eat animal products for sustenance or health.
https://ourworldindata.org/land-use-diets
Animals are really inefficient in converting plants into calories.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5899434/
"Plant-based replacements for each of the major animal categories in the United States (beef, pork, dairy, poultry, and eggs) can produce twofold to 20-fold more nutritionally similar food per unit cropland. Replacing all animal-based items with plant-based replacement diets can add enough food to feed 350 million additional people, more than the expected benefits of eliminating all supply chain food loss."
https://www.wri.org/data/animal-based-foods-are-more-resourc...
Animal-based Foods are More Resource-Intensive than Plant-Based Foods
https://www.eurekalert.org/news-releases/917471
Feeding 10 billion people by 2050 within planetary limits may be achievable
A global shift towards healthy and more plant-based diets, halving food loss and waste, and improving farming practices and technologies are required to feed 10 billion people sustainably by 2050, a new study finds.
And we don't really need an optimal mix of amino acids as long as we get enough amino acids. Fretting about precisely balancing the mix is unnecessary.
Seriously, listen to the interview I linked above and then read the referenced journal articles. That will clear up some of your misconceptions.
I do agree that we should shift away from monocrop agriculture to produce fodder for cattle feedlots and toward regenerative agriculture. Some farms are now doing that with productivity comparable to factory farming so it will be interesting to see if that model can be scaled up enough to cheaply feed a huge population.
That's not true.
25% of your plate should be proteins (lentils, beans, tofu, tempeh, seitan, peas ...), 25% whole grains (brown rice, quinoa, whole wheat bread, whole grain pasta), 30% vegetables (variety of colors to get different nutrients), 10-15% fruit (apple, banana, berries), 5-10% fats (avocados, nuts, seeds, or a drizzle of olive oil).
That's it. Variety is the key. The only supplement you need is B12, which you can get from either pills or fortified milk, yogurt, cereals, and other sources.
It's sad how confidently wrong many HN users are whenever we have discussions about diet and nutrition. People read something somewhere that aligns with their preconceived biases and then they repeat it back without doing real validation.
If your want to see empirically what actually works then ignore the gurus and junk science you see online, and instead look at the diets of masters athletes who have been competing at high levels for decades (including recovering from injuries). The percentages on their plates are substantially different from your numbers, and the majority eat a significant amount of animal products.
> instead look at the diets of masters athletes who have been competing at high levels for decades (including recovering from injuries).
https://pha.berkeley.edu/2021/04/11/benefits-of-plant-based-...
Research studies have found that plant-based diets are effective in decreasing weight, creating leaner bodies through decreases in body fat percentage, and enhancing athletic endurance
https://www.runnersworld.com/news/a25797700/plant-based-diet...
New Research Shows a Plant-Based Diet Can Improve Recovery Time - It’s good for your cardiovascular health, too—especially if you usually run long distances
https://pubmed.ncbi.nlm.nih.gov/30634559/
Plant-based diets appear to reduce cardiovascular risk factors and offer potential performance advantages for endurance athletes by improving body composition, glycogen storage, vascular function, and reducing oxidative stress.
https://www.veganfoodandliving.com/features/vegan-athletes-p...
"This is a message to all those out there who think that you need animal products to be fit and strong. Almost two years after becoming vegan I am stronger than ever before and I am still improving day by day."
“Don’t listen to those self-proclaimed nutrition gurus and the supplement industry trying to tell you that you need meat, eggs and dairy to get enough protein."
“There are plenty of plant-based protein sources and your body is going to thank you for stopping feeding it with dead food. Go vegan and feel the power" - Patrik Bouboumian
> https://peterattiamd.com/donlayman/
"Don currently consults for many food industry companies including Kraft, Nestle, Hershey, the Dairy Council, the Egg Board, and the Beef Board"
I think that this Don who's cozying up with all the big players in the food industry must be a real beacon of impartiality and enlightenment. Who needs objectivity when you can have a buffet of conflicting interests?
You are a human being. We all know what your nutritional needs are. Since you are posting here, we now also know your preferences. But they don’t require spending 1000s of acres of agricultural land and carbon emissions to satisfy.
The real solution here is of course a carbon tax to capture the externalities of soy- and corn-based ranching. A “Pig”-ouvian tax, if you will. Alas sentiments like yours are why we can’t solve problems in an efficient way.
https://ourworldindata.org/land-use-diets
"The land use of livestock is so large because it takes around 100 times as much land to produce a kilocalorie of beef or lamb versus plant-based alternatives. The same is also true for protein – it takes almost 100 times as much land to produce a gram of protein from beef or lamb, versus peas or tofu."
"Beef has an energy efficiency of about 2%. This means that for every 100 kilocalories you feed a cow, you only get 2 kilocalories of beef back."
> Getting the optimal mix of essential amino acids is crucial for health
Animals have nothing that we couldn't obtain from plants.
It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes.
- American Dietetic Association
A vegetarian or vegan diet can be suitable for everyone, regardless of their age.
- NHS UK
It is possible to follow a well-planned, plant-based, vegan friendly diet that supports healthy living in people of all ages, and during pregnancy and breastfeeding.
- British Dietetic Association
For adults, protein from two or more plant groups daily is like to be adequate.
- World Health Organisation
Killing off the animal husbandry is a short sighted solution.
Vegan's are measurably weaker.
Children raised on a vegan diet have worse heart health, weaker bone structure and a shorter stature.
There is an evolutionary reason we're omnivores.
Veganism is a religious belief and rightly has no place in these conversations.
I'd think that with warming and water wars, it would be adapting from above crop irrigation to soaker hose style irrigation.
This line has been moving east, if I recall correctly, and if we don't irrigate more we're losing land from the breadbasket.
As you say, though, the line seems to be moving east at least a bit. Maybe wind patterns coming north out of the Gulf of Mexico are shifting?