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Hi I’m Wendy Zukerman… You’re listening to Science Vs from Gimlet Media… this is the show that pits facts against froth. On today’s mini episode: MilksLast week, we looked at veganism….  And it got us thinking about all the different kinds of vegan milks out thereI mean, it’s become an ordeal just trying to order a coffee…. If you’re not going for dairy… there’s soy, almond, rice, oat, macadamia, cashews…hemp milk.

These milks claim to be better for the environment… than good old fashioned dairy milk. And they’re really catching on…  sales of these alternative milks have more than doubled in the last decade[1]

In fact… this alternative milk craze has grown so much that the FDA[2] recently stepped in to question whether we should call them milks at all… afterall: almonds don’t lactate[3] …That’s udderly ridiculous. Rather than curds and weigh in on that debate: we’re going to call all these alternative milks shmilks.

And today we’re going to tackle their claim that they’re great for for the environment. [4] [5] [6] [7] [8] [9]...

We found the perfect scientist… to help us answer this question…and we shmilked him for all he’s worth. .

JP My name is Joseph Poore… P-O-O-R-E

WZ Is that related to the fact that you study milk? Cause you pour milk?

JP No,  haha..I think there are too many puns

Moooooooo-ving on . If you just listened to our episode on Veganism… you’ll remember Joseph, he’s a researcher at the University of Oxford[10]. And his team created a huge database filled with info on how different milk farms affect the environment. He’s just published a paper[11] that looked at dairy and soy milk. And then we asked him to pull the numbers from his database on three other popular shmilks oat, rice and almond. And by the way his database has a lot of farms.

JP there’s about  7800 who produce rice 150 oat farmers, and about 200 farmers who produce nuts

All together, the data you’re about to hear is from about 10,000 farms from around the world[12]. This is the biggest study we could find on this topic. So when it comes to the environment…If you look at dairy milk, almond, soy, oat and rice ... who's doing the most harm here?

WZ which is the worst?

JP the worst on every indicator is dairy milk. 

<Mooo sfx>

Yep while different farms do different things… on average shmilks -- all the smilks - … beat dairy.[13] This shouldn’t come as a shock because last week we mentioned eating meat and animal products is typically worse for the environment than going vegan… but what we didn’t say is that milk is a big part of the reason why[14] [15] . So for example, making dairy products, like milk, it uses a tonne of land.[16] [17]

 JP Globally, cows graze 830 M hectares of land, an area the size of Brazil.

WZ Oh my Gosh

JP Yeah it's shocking isn't it, just a huge amount of land just to provide milk and milk products.

Joseph found that globally, it takes, on average. 9 times more land to make a glass of dairy milk than any of the other schmilks.[18] ….  

But if you dig deeper into the shmilk world, it becomes clear pretty quickly that these shmilks have their own environmental problems.  So we’re going to take a look at almond, rice, soy and oat milk, one by one, to figure out how environmentally friendly they really are.

And we’ll start with almond milk. You might have heard that making it uses a ton of water -- and Joseph found that this is actually true.

Almonds[19]. you have to irrigate them. And given that almost all of america’s almonds are produced in california[20],[21],[22]  where there’s tremendous pressure on water resources, almond probably does rank worst.[23]  [24] [25] [26] [27]

Another worldwide study found that almonds take at least 4 times more water to grow than rice, oats, or soy beans[28].

So now we know almond milk’s achilles heel: water.

Next up Rice. It uses a lot of water too… but where it flopped was greenhouse gases.… In Joseph’s study producing rice milk emitted the most greenhouse gases… although not by much[29] And that’s because of this really surprising thing that happens when you grow rice in paddys.

JP so to grow rice you typically need to flood it and in the flood water, the bacteria create methane

That’s right. Innocent looking rice has a dirty little secret. Bacteria and other micro - organisms… that burp out methane live in the soil where rice is grown. [30] And when the fields are flooded, these bacteria go crazy and end up pumping out more and more methane[31].  All that flooding leads to another big issue for rice.

JP Fertilizer that’s applied to crops can run off land and enter water bodies

When the water runs off the paddy it takes fertilizer with it… spreading it into the environment… . [32] This has happened in one of China’s largest lakes[33] … and it wreaked havoc on the natural ecosystem. And while lots of crops have this runoff problem, Joseph found that making rice milk creates about three times[34]  more fertilizer runoff than our other shmilks.

Ok. That leaves soy and oat. What’s their vice? Turns out, it’s land.  Joseph found that to make a glass of these shmilks… on average you need more land than almond or rice.[35] And some soy is grown in the Amazon… which mean we could be cutting down rainforest to get our milk [36] [37]...

So with all these things to consider… almond milk guzzling water… rice milk burping out greenhouse gases soy and oat milk eating up land … so which is the best shmilk if you want to save the environment?

WZ so who's the winner -01


Yeah, that's the sound of Joseph really not wanting to choose, because he says...

I think you're pulling at straws,

 they’re all so low impact compared to dairy milk, if we chose to change to any of them it would be beneficial. I can’t give it to you I can’t give you a clear winner.

Ok so Joseph doesn't want to pick one schmilk to rule them all ... because even though they have their environmental vices… dairy he says is just so much worse. … It produces more greenhouse gas emissions[38] [39] , uses more water... and land than the shmilks[40] …

And Joseph says these problems with dairy ... they can really add up. To make his point he gave us a kind of extreme example and crunched the numbers on what would happen if everyone in the world switched from dairy to soy…  he said It would save half a billion hectares of land[41],  almost a billion tonnes of greenhouse gases[42]… and just heaps of water…  

It would save 250 kilometers cubed of irrigation water per year…

it would save the same amount of water as if everybody in the world stopped having showers or baths for a year[43] -01

WZ oh my gosh- WZ:  it's funny cause in NY it almost feels like this silly thing, like I don't know which milk to pick. And then when you hear those numbers. I don’t know. -This is actually serious

JP it's really serious they are very surprising numbers Switching to plant based milk does seem to be a positive thing for the planet.

So, when it comes to the environment, it’s not udderly ridiculous to reach for these shmilks.

That’s Science Vs Milks … Shmilks


This episode was produced by Meryl Horn with help from me, Wendy Zukerman, along with Rose Rimler and Odelia Rubin. Our senior producer is Kaitlyn Sawrey. We’re edited by Blythe Terrell. Fact checking by Michelle Harris. Mix and sound design by Emma Munger. Music by Emma Munger and Bobby Lord. For this episode we also spoke to Adrian Williams, Niels Jungbluth, Frank Mitloehner, and Adam Drewnowski. Thank you so much for your input!

Next week we’re tackling Gentrification: Is it really that bad?

Everytime i move to a neighbourhood gentrification seems to find it and I get kicked out. 

I’m Wendy Zukerman -- fact you next time...

[1] 2009 and 2015 


[3] Food and Drug Administration Commissioner Scott Gottlieb said “An almond doesn’t lactate, I will confess.” in defense of questioning whether vegan “milks” can call themselves milks

[4] And consuming more plants can be easier on the earth, too. That looks like progress to us.

[5] We are committed to sourcing quality ingredients and we work with farmers who share our sense of environmental stewardship.

[6] Our goal is to always deliver products that have maximum nutritional value and minimal environmental impact.


[8] Moreover, many of the nasty pesticides that are used on oats in the rest of Europe are totally forbidden in Sweden.

[9] Producing one carton of Silk uses 80% less water than producing one carton of typical dairy milk.


[11] Published June 2018

[12] 1,800 (dairy)+ 354 (soy) 150 (oat) + 7800 (rice) + 200 (nut) =  10,304 total

[13] The environmental impact of vegan drinks compared to whole milk- this is the only other analysis we could find comparing these milks, and they also found dairy is much worse

[14] table 9- diary is more than soy or almond

[15] From j.p. Analysis: on average, 3.2 kg CO2 (equivalent) per L milk. Soy, oat, rice, almond are all 1.2 kg CO2 or less.

[16] 830 million hectares of pasture are grazed to produce raw milk (size of Brazil) today. [570Mha = milk we drink; 260Mha = cheese]. [email from J.P.] 

Brazil land area:  8,358,140 sq km [ 1 square km = 100 hecatres] = 835,814,000

[17] table 1. Liquid milk is “The most consumed, processed and marketed dairy product.”

[18] From j.p. Analysis: on average, 8.9 m^2 on average per L milk. Soy, oat, rice, almond are all under 1 m^2

[19]  Almond skins are peeled off after the kernels are bathed in 85ºC–100°C water for 2–5 minutes. 

[20] In 2016 Australia produced 82,000 tonnes of kernel and the USA produced 1,000,000 tonnes of kernels.

[21] , the USA being the world’s largest producer of this crop, with some 80% of the global market (FAOSTAT 2016). USA with 350,000 ha of almond crop produces more than 800,000 t,

[22] As for the importance of irrigation, the United States spans many agroecological regions, which include large areas that depend only on rain-fed agriculture, others that depend on rain and irrigation waters (both surface and ground, but largely local water resources), and then California, which depends on a unique, extensive, energy intensive system to store and deliver water from water-rich regions to arid regions. Dependency on this system means that some agricultural regions in California depend on extremely energy-intense water resources for irrigation...

[23] From J.P. email for total water needed to make 1L shmilk: soy 28, oat 48, rice 270, almond 371.

[24] Research has shown that trees are able to survive on as little as 7.6 inches of water (Shackel et al 2011), but they produce maximally with 54 to 58 inches in many areas of California Sanden 2007.)

[25] Pg 41: Years ago, many CA almonds were grown without irrigation, using only soil-stored rainfall as water storage. As production pressures intensified, almond orchards received applied irrigation water to improve their yield and quality. … allowing an almond tree to become stressed by inadequate water early in the season will reduce yields by slowing hull, shell, and kernel enlargement. 

[26] “Do not scrimp on post-harvest and September irrigation of almonds.”

[27] Almond orchards grown in the traditional system, as previously described [NOT the system used in California], produce low yields and show strong tendencies towards alternate bearing. P . 720


Amounts of crop needed to make shmilks are roughly the same: (from JP email): soy 90g, oat 100g oats, rice 120g rice. Almond 60g almonds. Even when you take into account that you need less almonds per liter, almond milk still takes more water to make. Looking at Table 4 in the source, and using the figure for shelled almonds (16095) I get figures from 1673 (rice, paddy) and 3736 (soy milk) that's like 4-10 x

[29] JP emailed analysis: From j.p. Analysis: on average, for 1 L product, you produce (units = kg CO2 (equivalent): Soy 1.0, oat 0.9, rice 1.2 , almond  0.7


[31] After flooding, oxygen is rapidly depleted in the bulk soil. Anaerobic microorganisms, such as fermentative bacteria and methanogenic archaea, predominate within the microbial community, and thus methane is the final product of anaerobic degradation of organic matter.

[32] [from JP email] The main issue with rice paddies is runoff/drainage water:

  • The rice are grown in a few inches of water, then that water is drained (you flood and then drain rice to drive growth and prevent weeds).
  • That water often contains quite high levels of dissolved N and P (when rice is fertilized, which almost all rice is)
  • The drainage water tends to go into rivers / streams / and eventually lakes and oceans

The other route is leaching (i.e. where fertilizer passes through the soil and eventually into underground water bodies and eventually into streams/rivers). But leaching is actually very low in rice paddies because of the hard layer of soil below the topsoil. If you didn’t have this hard layer of soil, the flood water would just drain out the bottom of the field….

So to be clear: its drainage of flood water that causes eutrophication in nearby rivers/streams, and then lakes/oceans.

[33] The amount of N (nitrogen) and P (phosphorus) inputs in this region has significantly increased in the past two decades, in parallel to acceleration of eutrophication of Taihu Lake, which is the third largest freshwater lake in China. Pollution from the rice production system is considered to be one of the most important contributors to environmental deterioration.

[34] From J.P.’s analysis: average eutrophication (kg PO43 eq): soy milk 1.1, oat milk 1.6, rice milk 4.7, almond milk 1.5

[35] Land use (m^2) soy .7, oat .8, rice .3, almond .5 (from j.p. analysis)

[36]  Brazil’s soy beverages market was worth USD 315.14 million in 2017 and is estimated to reach a value of USD 420 million by 2023, at a CAGR of 5.49%.

[37] For example, properties greater than 2000 ha in size, which tend to be cattle ranches or soy farms, constitute only 1% of all agricultural establishments in the nine Amazonian states but control 46.8% of all land converted from forest or cerrado to agriculture

[38] table 9- diary is more than soy or almond

[39] From j.p. Analysis: on average, 3.2 kg CO2 (equivalent) per L milk. Soy, oat, rice, almond are all 1.2 kg CO2 or less.

[40] From j.p. Analysis: on average, 8.9 m^2 on average per L milk. Soy, oat, rice, almond are all under 1 m^2

[41] THESE STATS ARE FOR DRINKABLE MILK ONLY (NOT CHEESE, etc).  Use 630 million hectares less farmland, an area the size of the European Union and India combined. [We use 85Mha of arable 570Mha of pasture to produce milk. To produce the same amount of soymilk will take just 30Mha of arable land. 570+85-30 = ~630Mha less land]

[42] The stats I gave you at the end were JUST for milk. I.e. switch from milk to soymilk. [it would] Reduce greenhouse gas emissions by almost a billion tonnes a year. Same as Germany’s total emissions.

[43] Save 250 kilometres cubed of irrigation water a year. Same as if everyone in the world stopped having showers or baths.