The Steaks are High for Greenhouse Gases

Last week we wrote about the enormous detriment of the agriculture (and specifically beef) industry on the environment.  The effects are primarily due to the sheer size of the cattle population and the amount of resources they consume:

  • 2,500 gallons of water per pound of beef
  • 1,000 gallons of water per gallon of milk
  • 2-5 acres of grazing land per cow
  • 1.5 billion cows

Cattle take up a lot of space, they eat a lot of feed,  they consume an enormous amount of water.  The one thing missing from this eating, drinking, sleeping machine?  Poop.  That's a topic society shies away from, but the animals we farm create massive amounts of waste.  Every day, dairy cows produce 112 pounds of waste, and cattle produce an additional 63 pounds.  Humans have extensive infrastructure for dealing with waste, but cows don't.  There aren't any treatment plants that deal with the waste from a billion and a half cows.

So what - it just gets washed away, right? No.  Sure some waste is washed away, but this doesn't help the situation.  And what about those calls of nature that do not?  Let's find out more.

Solid Waste

Outside of the modern era (meaning the past 70 years or so), the sheer extent of cow excrement produced is unprecedented.  And it has had some truly horrific consequences.  As the solid waste is washed away, it ends up in streams that lead to rivers that lead to larger bodies of water.  Think about the amount of land that surrounds all the tributaries flowing to the Mississippi River (known as a watershed) - or just check out the map below.

Mississippi Watershed (Source: United States Geological Survey)

Mississippi Watershed (Source: United States Geological Survey)


Solid waste from cows in that area is flushed down through the Mississippi River and into the Gulf of Mexico.  An endless stream of waste-laden and nitrogen-rich water, creating a huge dead zone around the Louisiana Coast.  The ecological process that causes a dead zone is a bit complex, but put simply:

  • Warm fresh water is separated from the cold salt water.  This creates a barrier to oxygen diffusion in waters unexposed to the surface.  No oxygen = no life.
  • The waste-water is high in nutrients, promoting mass expansion of algal populations.  There's good algae that feed aquatic life; however, waste-intensive water can produce harmful algae blooms that have been known to generate a wide array of neurotoxins, liver toxins, and skin toxins.  Not the sort of thing you want flavoring that cup of water.
  • When algae die, they sink to the bottom where they are subsequently decomposed by bacteria.  This decomposition uses oxygen, further depleting oxygen levels in the lower depths.  Low oxygen levels force mobile organisms (e.g. fish) to leave the area, while non-mobile organisms (e.g. mussels) die.

The number of these dead zones have increased to 550 globally over the past few decades.  Pollution from animal waste and agriculture fertilizers are primary contributors.

Gulf of Mexico Dead Zone - (Source: Nancy N Rabalais, LUMCON, and R. Eugene Turner, LSU)

Gulf of Mexico Dead Zone - (Source: Nancy N Rabalais, LUMCON, and R. Eugene Turner, LSU)

Gaseous Waste

Not only are cows prolific producers of solid waste, they also release substantial amounts of methane and carbon dioxide by passing gas and through respiration, respectively.  In fact, livestock and their byproducts  account for 51% of all greenhouse gas emissions (WorldWatch).  

51% of all greenhouse gas emissions!

  • Cows produce 150 billion gallons of methane per day (International Business Times)  - a gas with global warming potential 86x that of carbon dioxide (Science)
  • Livestock are responsible for 65% of all human-related emissions of nitrous oxide - a gas with global warming potential 296x that of carbon dioxide (FAO)

Cow farts are quite literally killing the world.

What does this all mean?

It means that driving cars and powering homes is not the only factor leading to climate change.  It means that there are more effective ways that each individual can reduce their impact on climate change than turning the lights off, carpooling, or buying energy-efficient appliances.  Now, we're not advocating against those things.  If everyone participated in these practices, we would see a great response.  What we are saying is that there's more to this climate saving equation than what is classically portrayed.

It also means that agriculture - livestock, and cattle in particular - do impact local, regional, and global environments far more than most people know.  The industry is responsible for HUGE amounts of forest destruction, pollution, destruction of marine habitats, and MORE THAN HALF of greenhouse gases.  Even if we transitioned to 100% renewable energy tomorrow, the world would still be in trouble because of the agriculture industry.

Final Word: If you truly want to make a difference, eat less beef.  Drink less milk. Skip beef (or better yet, all meat) once a week.  Even once a week will make a dramatic difference.  Spread the word.



Happy Earth