does beef contribute to climate change? a lot of you messaged saying you were frustrated and
confused with a video from a channel called "what i've learned" suggesting that beef is not
that polluting, it's basically no big deal. so let's take a look at the controversy and see if we can
make sense of this. raising animals to eat causes greenhouse gas emissions. a big part of the problem
is growing all of their food, which creates more emissions. that's not contested, everybody knows it
and the video acknowledges it. of course livestock have an environmental impact. the question is the
magnitude. is this a big problem or is it minor? the video interviews a scientist who says eliminating
all animal agriculture in the US would make a small difference. it would only reduce greenhouse
gas emissions by 2.6% and if only some people cut back then it would be a tiny effect,
basically meaningless. the video cites this study to back that up. it's published in a respected
journal, i've published several studies in that journal so i obviously don't have a problem with it,
it, so let's look at what the study actually did. they ran a simulation where we stop raising
animals to eat but we keep growing all of their food. we keep growing tons and tons of corn even
though all the cows and pigs and chickens are gone. in fact, the free space left by the animals,
we use it to grow more crops, but at the current proportions we use right now, with all the billions
of animals. so a lot more corn. and because we don't have the manure anymore, we have to synthesize
fertilizer industrially to grow all of those crops, creating more emissions. so the conditions
they chose to simulate in the study are that we are condemned to produce fertilizer industrially
to grow tons and tons of corn we don't need to feed billions of animals that don't exist anymore
so what do we do with all those tons of corn that are left? well, according to the conditions
they chose for their simulation, we would eat it. so in their simulation our diet would be 80%
grains and mostly corn. and not a normal amount of food, a huge amount, an excess of dietary energy
because we have all this leftover corn and no cows to eat it. and not surprisingly, they found
that this diet was not nutritionally ideal, that it led to some potential deficiencies. and even
in this outlandish scenario where we just keep producing tons and tons of crops we don't need,
they still found it was better for the environment, they saw a statistically significant reduction in
emissions compared to the current system with all the animals. but they conclude the magnitude of the
difference wasn't that impressive if we do it like that. yeah, if we keep producing all of the animal
food even though all the animals are gone yeah, the emissions are not going to come down as much
but no one is suggesting that as a solution. now, maybe this sounds a bit too weird to be true, maybe
i'm presenting the study unfairly. how do you know you can trust me? well, you don't need to. several
teams of scientists from different countries wrote to the editors of the journal expressing their
concern about the study and the journal published those letters. here's one from european scientists
titled "causing confusion in the debate about the transition toward a more plant-based diet". it
explains that "in the study, nutrient deficiencies may have arisen from the unbalanced diet assumed
in the plant-based scenario, with grains being 80% of daily consumption". here's another
letter, from the US. titled "without animals, farmers would reduce feed crop production". yeah,
farmers would stop growing food for cows if there weren't any cows around. the titles of the
letters almost tell the whole story. "the authors of the study unrealistically assume that without
livestock, americans would continue to grow animal feed and just incorporate it into human diets"
"feed crops take up 75% of US crop land. without livestock, all that land could be used to grow
vegetables, biofuel crops, food for export and provide critical habitat for native wildlife
by eliminating the need for animal feed, farmers could transition to a wider variety of grasses,
grains, pulses, vegetables and fruits that would be healthier for humans and the environment
here's another letter by scientists from harvard and oxford, called "feedlot diet for americans" and
then they added "resulting from a misspecified optimization algorithm". because that's what we
nerds sound like when we throw shade... "the way the authors did the study is particularly nonsensical
as exemplified by their plant-based scenario, an energy intake twice that of an average adult at
almost 5,000 calories a day, with about 3,000 calories a day coming from corn" that's
24 ears of corn every day, per person. aaand a half. "and out of the 5,000 calories of food, over 4,000
calories from grains". every day. "more diverse diets, including vegetables, fruits, nuts and seeds, legumes
would be possible. however, unfortunately all the results in the study were based on
implausible scenarios and therefore cannot represent realistic examples". now, the authors
replied and they don't dispute the basic facts of the study, all those numbers, they basically said
this is the scenario they wanted to test. if farmers did not change their crops and kept
putting out corn and that's all that people had, what would happen. that was their focus
they conclude "our study's approach differs drastically from others in this field". so yes,
if we eliminate the animals but keep producing all of their food, and synthesize fertilizers to
grow that food, and start eating 5,000 calories a day, over half of which from corn, then yeah,
the reduction in emissions is not going to be huge and health-wise that's not going to be great
that's what the study tested. so this is the study they cite in the video to make this key point that
it's not worth moderating animal agriculture, don't even bother because the effect is too small. what
the study didn't test is what everyone advocates for: moderate animal agriculture, especially beef,
moderate the tons of corn in monoculture, that frees up land and water and uses less fertilizer
and generates less emissions and we grow some more fruits and vegetables and legumes
is that doable? that's an important discussion we should be having as a society but this study
didn't test that. now, it's okay to cite the study, it's not trash science, we don't just dismiss it,
it's interesting data in a way, it's good to know what happens in that specific scenario, i guess
but if we're going to bring this up we have to understand what the study actually did and
be clear about it, not just throw out numbers like soundbites without understanding them,
that just confuses people and sets us all back. okay, so what happens in more realistic conditions
where we don't just keep growing the cow food for no reason? is it worth it to moderate animal
production? has that been tested? it's been tested many times, by different teams of scientists, in
different institutions, from different countries. here's one study, out of oxford: "moving from current
diets to a diet that excludes animal products has transformative potential, reducing food's greenhouse
gas emissions by almost 50%". and they point out something important: "the US meat consumption
is three times the global average, so for us westerners, dietary change has potential for far
greater effect, reducing food emissions by 60 to 70%". that makes total sense. since we eat
a lot more beef, if we in the west change our diet that's going to affect the whole globe a lot more
than if Namibians change their diet. that scenario without animal products would mean a 28%
reduction in global greenhouse gas emissions, so emissions from food cut in half or more and global
emissions, total, down by 28%, almost a third. not 2.6%, the number they found when we just keep growing
all the cow food. okay, but completely eliminating animal products is not realistic, what if we just
moderate it? a 50% reduction in animal products could mean 20% less total emissions
especially if we avoid the products with the largest impact. these researchers explain: "animal
products generate the majority of food related emissions, over 70% of agricultural emissions, and
changes in meat consumption dominate the impacts on emissions". they compared the impact of
moderating animal foods to other strategies like wasting less food or technological improvements
here are the results: drastically reducing food waste cuts food emissions by 9%. new
technology, slightly more, and changing our diet, moderating animal foods, 56% less emissions
from food. and all three strategies combined, a bit over 60% reduction. and they're not talking about
something drastic like everybody going vegan tomorrow, they're looking at a flexitarian diet
that moderates meat and favors fruit, vegetables, nuts and legumes. so kind of a mediterranean
pattern. same recommendations as for health, we've covered that here in like 100 videos, takes care
of health, takes care of the planet. if doing that to save the planet is extreme and radical then
i don't know what to tell you. okay, what's the actual impact of this in the grand scheme? is it
worth it? that's what we want to know. they explain: "greenhouse gas emissions cannot be sufficiently
mitigated without dietary changes towards more plant-based diets". that's a far cry from "oh don't
bother, the effect is too small, don't even do anything". different study, different scientists:
"consuming less animal products, particularly beef, is an effective way of reducing dietary emissions"
different one: "eliminating animal agriculture would negate 56% of emissions". okay, what
if we just moderate them? "substantial reductions in land and emissions could be achieved by switching
from cattle to pigs and chicken. they would still have substantially greater impact than plants
but less impactful than red meat". why do they all keep harping on the red meat? do all environmental
scientists just hate beef? no, it's because when you look at the environmental impact, it's completely
disproportionate. here's the emissions for plant foods, the further to the right of the line
the bigger the emissions. here's eggs, dairy, fish, chicken, pork, and then ruminants like beef
it's on a different league even from the other animal products. "ruminant meat like beef or lamb
has environmental impacts 20 to 100 times those of plants, the other animal products are 2 to 25
times higher than plants. this trend holds whether foods are matched by protein content, by serving
or by mass". that's in large part because beef requires a lot more feed. for example, producing
one pound of milk or eggs requires two to three pounds of plants, for poultry is two to five,
pork three to nine, but for beef it's 24 to 49. so less cows means a lot less crops we gotta grow
so yeah, if your simulation just keeps growing all the cow feed anyway, that's gonna make a
difference. okay, what if we just feed cows grass? that's better, right? for the animal, probably
unfortunately, for the environment it doesn't seem to solve the problem. this study found
that grass-fed beef requires more water, more land, more fossil fuels and a bigger carbon footprint
than conventionally raised. that's in part because they grow slower, it's a more natural process
so the emissions they cause extend over time and the total ends up being a little higher
these scientists explain that "although ruminants convert grass, including on land unsuitable for
crops, into human edible protein, the environmental impact of this conversion is immense". so does that
mean that all beef is exactly the same? no, there's big variation, with some producers causing a lot
more emissions than others, so there is room for optimization. but even the cleanest beef was worse
than most other animal foods and much worse than plant sources of protein like beans, for example
so dietary change, changing the proportion of foods we eat, can deliver environmental benefits not
achievable by just tweaking the production process. so the solution probably will involve optimizing
the production of beef as well as moderating it at societal scale. okay, what about fossil fuels? isn't
that the real problem? can't we just cut back on fossil fuels and leave our food alone, because we
like it? can't we just do that? this study published last year looked at exactly that question. "reducing
emissions from fossil fuels is essential but even if fossil fuel emissions were immediately halted
current trends in food production would prevent the achievement of climate targets. thus, major
changes in how food is produced are needed". they explain that to meet climate goals we have to make
"substantial changes to our food system as well as other sectors". of course, this is all connected,
they show that if we completely eliminate fossil fuels over the next couple decades, not moderate
them but bring them to zero, then we'll have a bit more leeway on the food changes, we'll still have
to make some but maybe less drastic. realistically, in order to have a shot at solving the problem
we will have to make changes to transportation and energy but it's not enough. food production
is a big chunk of emissions so we need to moderate a little bit everywhere to have a shot at making
a meaningful change. we can't play this game of "just change those things over there and not the
thing i like", it's not going to work. there's lots of powerful interests and people who would like
fossil fuels to not be reduced, but we got to do it, we can't just keep pushing the blame over. now,
this does not mean that every single human is going to have to completely overhaul their diet,
some people are not going to be in a position to make huge changes, for health reasons or whatever
it may be, other people are just not going to do it, that's reality. hopefully the rest of us can do a
bit extra to cover for those who can't. so the goal is not to shame each other, it's not to browbeat,
it's to look at the evidence and have this crucial conversation and work together to beat
a common enemy without bending the facts in either direction. not exaggerate them for effect and not
minimize them for mental comfort either. i know it's tempting to say "let's not change anything,
it doesn't matter, don't worry about it, let's just keep doing what we're doing". i know that's a much
more pleasant message to hear and i know that what i'm saying is boring, unpopular, ruining the party.
i get all that. but stating the facts clearly is the only way forward. are animals, and beef
in particular, a significant source of emissions? yes. is moderating them going to help? yes. is it a
silver bullet, is it going to solve climate change by itself? no, we're going to need to make changes
to other sectors as well. now, with every video we put out our real goal is not to throw facts at
you or to fact check, it's to provide the tools so that you can go through this process yourself, so
that you can see through confusion, you don't need us to fact check every little thing that pops up
so when you look at a study, when you look at a set of data, you've got to make sure that you, number
one, pay attention to what they actually did, the experimental design. what was actually tested, not
just a headline or a flashy number. and number two, look at the context of the field, everything that's
been done on that topic, we call that totality of evidence, and see how that study fits into that
context. if we fail to do either of those two we risk getting really confused. now remarkably, here
they managed to make both of those mistakes at the same time, so the result, inevitably, was colossal
confusion. i mean it couldn't have gone any other way. the video even goes as far as saying that this
scientist researches ways to make animals less polluting, that's his job. "in fact, his job is to
research ways to reduce livestock's environmental impact". so, reducing their impact by tweaking the
production process, that's important, that's a career. but reducing their impact by raising a bit
less cows, that's not worth it because their impact is not that big to begin with so don't even bother
i mean, this is raising cognitive dissonance to an olympic sport
but i'm sure they mean well, i'm sure they believe what they say, so nothing personal, and the channel,
i really don't blame them, i'm not familiar with the channel to be honest with you but they did
a lot of things right. they had a scientist on for more expertise and more substance,
they had citations on screen, and they were peer-reviewed studies, so they really tried,
that's a lot more due diligence than your average youtube channel, we got to recognize the effort
and i really don't blame them, they got unlucky, the message of the video is the exact opposite
of the available evidence. it happens, not the end of the world. we learn, we adapt, we move
forward. they touched on a couple other ideas, water and land use, we can make more videos if
there's interest but i hope this helps clarify things a bit because this is a crucial issue,
possibly the number one issue of our time, so let me know your thoughts, take care, see you next time