Skip to content

Myth busting – Part 10

Wow, we made it to Myth busting – Part 10! Let’s quickly look back over this mini-series so far and recap what we have covered.

In the previous nine instalments of this mini-series, we have read that:


Phew! It’s been a lot of fun writing this series – and I hope you are enjoying reading it!

But…you might have one last question, and this is now going to open up a whole can of worms. If we are supposed to be eating meat and fish instead of grains, and all those big juicy sweet pieces of fruit and veg are actually a relatively new ‘man-bred’ novelty.
Then, well…

Myth: It’s animal agriculture that is destroying the environment isn’t it? Haven’t you seen that film ‘Cowspiracy’? It’s all those burping and farting cows that are causing global warming. If we encourage people to eat less grain and more meat and fish there will be an environmental catastrophe, and besides there is not enough land to keep all those abused and mistreated farm animals fed and watered.


Truth: With respect to the good intentions of the makers of the film, in my personal opinion, that movie Cowspiracy is totally biased and wildly inaccurate, made purposefully to appeal to one particular paradigm, or one specific set way of thinking, namely veganism. Far from ‘exposing the truth’ these kind of mock-umentaries (known as a ‘mock-doc’ or a ‘docu-drama’) often do more harm than good by spreading misinformation, and they are nothing short of  propaganda made to promote the vegan cause, not to present a balanced view of reality.

I respect anyone who makes the choice to be vegan because they abhor cruelty to animals, I do too. But that is not what this is about.

There is so much misunderstanding in this area. Since Cowspiracy came out, it’s now ‘the latest trendy thing’ to talk about how animal agriculture is ‘the biggest cause of environmental destruction and greenhouse gases’ on Earth and so ‘everyone should just stop eating meat’ but this is just fundamentally wrong. Cowspiracy has certainly taken this issue (agriculture’s contribution to global warming) to a broader audience, but the so-called science in the movie is completely flawed, it uses data points cherry picked to provide a one-sided view, and it ignores loads of facts that don’t fit with the main goals of the presentation.

Let’s actually look at some reality.

Global warming and greenhouse gas emissions

Worldwide, the science is actually still split on whether this is even an issue or not. For years we’ve been told that we really are causing global warming, through human activity burning fossil fuels, but now other scientists say it’s just natural fluctuations in the Earth’s temperature, and there is almost as much science to argue that we are not causing ‘the greenhouse effect’ as there is science to prove that we are.

Just to add some perspective to the whole story, the most prevalent greenhouse gas in the atmosphere, accounting for well over half of all greenhouse gases, is actually water vapour and clouds. The amount of water vapour in the atmosphere varies over time and place, but on average we can think of it as making up around 65% of all greenhouse gas. You might, quite rightly, think that water vapour and clouds are actually completely natural – yes they are! Water vapour has been circulating in the atmosphere for a couple of billion years, and clouds are surely about as natural as it gets! We will circle back to this point later.

As an aside, if you study the last few million years, we are now at the end of a particularly warm period in recent history (known as an interglacial or interstadial period) within an overall quite cold period, and we are due an ice age ‘at any time’ now. Ice ages tend to crop up on a regular basis, we are sort of overdue one really, and it would actually be very good for the planet, and long-term for humans too. An ice age would lock up trillions of tons of sea water around the poles, dropping sea levels all over the planet by maybe 30 to 100 meters, this would expose far more land than we currently have, maybe for 5,000 or 10,000 or 15,000 years. We may lose most of Europe and North America, but there would be a lot more Asia and Oceania for us all to go live in! Something interesting to think about!

But whether the ‘greenhouse effect’ is real or not, and personally, I do think it is real, and I think that human activity has damaged the atmosphere (in terms of contributing carbon dioxide and other gases to the atmosphere; and also holes in the ozone layer; and breathing diesel particulates; and smog over cities, among other things), we really should stop burning fossil fuels now rather than waiting til they run out. We, all nations, as a global society, should be pushing to solar, wave, wind and tidal power much faster…much faster.

I think the truth is that atmospheric pollution and global warming is being caused by a lot of complex issues, some of which are covered below, and it’s not just one thing. It’s about more than just ‘burning oil and coal’ in cars and power plants, and it’s certainly about a lot more than just a bunch of cows farting and burping.

The movie Cowspiracy is guilty of incomplete thinking, preaching one-sided propaganda, and classic reductionist thinking. The movie suggests that it’s all very simple – lots of cow farts and burps (methane) plus lots of crop growing and water usage (carbon from irrigation pumps, tractors, etc.), makes for high GHG (greenhouse gas) emissions. Stop eating meat and drinking milk, and no more ‘enslaved and poorly treated’ livestock, means we solve the environmental disaster and animal cruelty all in one go.

It’s a nice idea, but it’s completely and utterly wrong.

In reality the amount of greenhouse gases (GHGs) released by cattle farting and burping, or the growing of cattle feed, in the grand scheme of things, is considerable, but while these emissions are significant, Mother Nature could be sucking up (sequestering) a lot of this carbon dioxide and methane if we let her do it her way. Before we dig into how that works, we need to establish some facts.

A few facts

I could go through the movie Cowspiracy with my finger on the pause button and stop it like every minute and pick holes in the data quoted. But honestly, I have no axe to grind, not with that movie, its makers, or the larger vegan community. I don’t really have any desire to ‘attack’ that movie in any way, I’m sure the people behind it have good intentions, and I just don’t have the inclination to go at it point-by-point like that. It would be a negative and somewhat soul-destroying exercise, and I’m not that kind of person.

But what we do need to do here is look at some straight facts and figures. We need to understand what this greenhouse gas problem is really all about.

The most prevalent GHG (greenhouse gas) is water vapour, as noted above. The next most prevalent GHG is carbon dioxide, then comes methane. After that comes all the smaller contributors such as nitrous oxide, CFCs and then a number of other nasty man-made compounds.

These different gases have different effects in the atmosphere, some are stronger than others, some last longer than others. So for instance, methane (such as cows fart and burp – the grown up word for “burping and farting cows” is ‘enteric fermentation’) can be up to 30 times ‘stronger’ than carbon dioxide in terms of its potency as a cause of the greenhouse effect, but it has a relatively short lifespan. After around 7 years, methane has degraded in the atmosphere to be no more harm than carbon dioxide, and it then quickly continues to degrade, become weaker all the time. After around 12 years, it’s all gone. By contrast, carbon dioxide can take up to 95 years to degrade to the same point.

When you see shock facts like ‘methane is 30 times stronger than carbon dioxide’ they tend to neglect to add ‘but it’s gone in a tenth of the time’. That’s what we call ‘cherry picking the data’ for your shock-umentary.

Nitrous oxide only contributes a few percent, perhaps around 5% to 6% of total global GHG emissions, but it is extremely potent, around 300 times stronger than carbon dioxide. Take a compound like the CFCs that used to be in refrigerators and aerosols, and that stuff is as much as 11,000 times stronger than carbon dioxide, and has a lifespan of around 100 years in the atmosphere. Manufacturers may have stopped using the stuff, but it’s still around, up there in the atmosphere, and it will be around for the next century. (By contrast, water vapour is only in the atmosphere for a week or two.)

These differing ‘strengths’ or potencies in the different greenhouse gases are generally taken into consideration when proper scientists quote data. Gases are measured in ‘carbon equivalents’ for comparative purposes. So if the data shows that 20% of all GHG emissions are carbon dioxide and 6% are methane, this is measuring the methane in ‘carbon equivalents’, meaning that the methane contributes 6% of the total greenhouse effect, and carbon contributes 20% of the total greenhouse effect, averaged out over time and geographical location.


Cowspiracy is a US made movie. The movie opens by stating data that agriculture is the biggest source of GHG emissions on Earth. This just is not true.

According to the US EPA (Environmental Protection Agency), which seems to me as good a source as any to quote, US GHG emissions in 2014 break out as shown in this screen-grab image here, just 9% from agriculture.

US EPA GHG Emissions 2016

If we screw down a level further, into the EPA data, and analyse that 9%, of all agricultural emissions, methane from livestock accounts for something between 18% and 23% of all GHG emissions from agriculture. Therefore, in reality, in the US, farting and burping cows (enteric fermentation) actually only produce a little under 2% of total GHG emissions.

US EPA Agricultural GHG emissions 2014

Additionally, here is comparable data for the 1990-2005 period, again sourced from US EPA, showing that the current situation has been consistent over the last two or three decades.

US EPA data 1990-2005

Charts source: Iowa State University

What we do see in this data, in the data from 1990-2005 and in the 2014 data, is that the overwhelming majority of greenhouse gas emissions from the US agriculture sector come from ‘agricultural soil management’ – not burping cows, not cow manure. Soil management. Please remember that, we have a lot to get through on this topic, so try to remember the US Environmental Protection Agency clearly states, and has done for the last 20 years, that agricultural SOIL MANAGEMENT is the thing that really produces greenhouse gases – about 5% of total US GHG emissions.

Meanwhile…back to the methane…

Sources of methane worldwide

This story about ‘cows produce so much methane, they are the #1 cause of greenhouse gases’ is just out and out completely wrong. Firstly, methane only accounts for a total of between 5% and 10% of the world’s greenhouse gas emissions. Secondly, ruminants (in total, farmed and wild) only produce about 20% of global atmospheric methane released annually. The EPA data shown above suggests that methane from livestock accounts for around 1.5% of US greenhouse gas emissions. The world’s natural and farmed freshwater wetlands (marshes, swamps, lakes, tropical wetlands, and rice paddies) produce far more methane naturally than all the cattle on Earth put together, approximately twice as much in fact.

Methane production from wetlands is an entirely natural process, which we have added to with extensive rice cultivation. Rice is the 3rd or 4th most cultivated crop on Earth. Data sources vary wildly, but according to NASA, enteric fermentation creates 16% of global methane emissions, where rice cultivation is responsible for 12% and natural wetlands produce 22%.

By contrast, the ‘Global Methane Initiative’ suggests enteric fermentation is responsible for 29% of methane emissions, and rice cultivation is only responsible for 10%. A peer-reviewed study produced by a group of experts from University of California, Irvine, and University of Pennsylvania, Philadelphia, who declare no conflicts of interest, state that wetlands produce 23% of the world’s methane, enteric fermentation produces 17% and rice cultivation produces 10%. This last set of figures seems like a fair representation to me.

If this data can be trusted, then it seems that far from livestock being the #1 source of total greenhouse gas emissions worldwide, farting and belching cows isn’t even the #1 source of methane emissions worldwide. If we all stopped eating meat and ate more rice instead, we would simply swap one source of methane emissions for another! And wetlands, including rice paddies, are a ‘worsening’ source of methane emissions, because for every degree the atmosphere warms up, wetlands harbour greater microbial communities, and emissions increase exponentially. This does not happen with livestock. Cows won’t burp any more just because the atmosphere got 1 degree warmer.

What about wild animals?

All the farmed ruminants in the world produce around 2% of total greenhouse gas emissions annually. That’s hardly “the leading cause” of pollution. And if those ruminants are supposedly the cause of global warming, what about wild ruminants? They fart and burp too! A few thousand years ago, before man hunted most of the Earth’s megafauna (large animals) into extinction, there were billions of large ruminants such as bison and moose, and there are still many wild ruminants today – deer, caribou, wildebeest, camels, giraffes and so on. Horses are not technically ruminants, but they are fermenters (hindgut fermenters, as against cows which are foregut fermenters) and they still fart a lot of methane.

If ruminants are the cause of greenhouse gas emissions, how was nature coping with all this 60,000 years ago when there were billions more wild ruminants and billions fewer humans?

If this methane issue is such a big deal, should we get rid of all the horses and wild deer and hunt giraffes into extinction? Yes? Bring your horses up here folks, the vegans want to shoot them. I don’t think so…

The annual spring caribou migration in Alaska and Northern Canada (Yukon Territory) is the largest movement of animals on Earth, it’s not ‘man-made’, it’s a stunning natural cycle, animals and land and climate all doing what they do without man’s guidance. The caribou have been living up there in the hard cold North since Neanderthal man was still around over 30,000 years ago. Caribou are ruminants, should we dash up to Alaska and kill them all? Maybe nuke them, would that be quicker?

What does Cowspiracy have to say about all this? Not much. I am afraid that in my opinion, the ‘mock-umentary’ Cowspiracy is just propaganda for the vegan movement, which often seems to aggressively promote its agenda using misquoted facts and incomplete arguments.

Enough about methane.

What have we learned so far?

  • The biggest greenhouse gas is water vapour – accounting for around 65% of greenhouse gases present in the atmosphere
  • Globally, agriculture is only responsible for about 10% to 12% of greenhouse gas emissions in total
  • Methane from burping and farting cows makes for around 1% to 2% of total GHG emissions worldwide – rice paddies are not far behind, and wild ruminants, including caribou, camels, giraffes and horses, all burp and fart too

Let’s break here then come back in the next part to look more closely at carbon dioxide and carbon sequestration – that is ‘taking carbon out of the atmosphere’.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: