September 13, 2007

Lancet: Eat less meat to combat global warming

The Lancet has released a report calling for a 10% cut in global meat consumption by 2050, a goal that would decrease greenhouse-gas emissions from agriculture and improve health for both rich and poor nations.

According to the report, as much as 22% of greenhouse emissions are from agriculture -- a figure similar to that of industry and, quite surprisingly, more than that of transport. Livestock production, which includes transport of livestock and feed, accounts for nearly 80% of these emissions.

Put into perspective, a kilo (2.2 pounds) of beef generates the equivalent of 36.4 kilos (80.08 pounds) of carbon dioxide, more than the equivalent of driving for three hours while leaving all the lights on back home.

Some quotes from the paper:

"Assuming a 40-percent increase in global population by 2050 and no advance in livestock-related greenhouse-gas reduction practices, global meat consumption would have to fall to an average of 90 grammes per day just to stabilise emissions in this sector."

"A substantial contract in meat consumption in high-income countries should benefit health, mainly by reducing the risk of ... heart disease... obesity, colorectal cancer and, perhaps some other cancers. An increase in the consumption of animal products in low-intake populations, towards the proposed global mean figure, should also benefit health."

More can be found here.

13 comments:

Anonymous said...

Put into perspective, a kilo (2.2 pounds) of beef generates the equivalent of 36.4 kilos (80.08 pounds) of carbon dioxide, more than the equivalent of driving for three hours while leaving all the lights on back home.

The direct emissions coefficient for beef is 7.7 lbs of CO2 per pound of meat. The "Livestock's Long Shadow" (LLS) factor for converting direct emissions into systemic emissions is 3.5. So direct emissions from a kilo of beef are 17 pounds, and under the systemic emissions model of the LLS report, it would come to 60 pounds.

The average fuel economy of a personal vehicle in the US is 19.5 mpg and the emissions coefficient of gasoline is 19.5 pounds per gallon.

Three hours of driving at 60 mph at that fuel economy will produce 180 pounds of CO2. These are direct, not systemic, emissions. At 30 mph (avg US driving speed), that comes to 90 pounds of direct emissions.

The average US household consumes a steady 1.36 kilowatts. The emissions coefficient of US electricity is 1.37 pounds CO2 per kWh. Three hours of electricity use will produce 5.6 pounds of direct (not systemic) CO2 emissions.

So, depending on driving speed, that comes to 96-186 pound of direct CO2 eq emissions, versus 17 pounds of direct or 60 pounds of systemic emissions.

If one eats chicken instead of beef, those numbers drop to 0.4 and 1.3 pounds.

Keep in mind that systemic emissions from transportation will be far higher than the direct emissions -- extraction, refining, other transport inputs, embedded energy in the vehicles and roadways, even the entire car-centric design of society.

Either way, the transportation and home energy emissions in this scenario are considerably higher than that of beef and not even in the ballpark with chicken.

That might have something to do with their modest proposal to cut consumption by 10% in 40+ years. Meat has a climate impact, but it's not nearly as great as some wish it were. Nor is all meat created equal.

To wit, from "Livestock's Long Shadow":
"Although industrial poultry production is entirely based on feed grains and other high value feed material, it is the most efficient form of production of food of animal origin (with the exception of some forms of aquaculture), and has the lowest land requirements per unit of output. Poultry manure is of high nutrient content, relatively easy to manage and widely used as fertilizer and sometimes as feed. Other than for feedcrop production, the environmental damage, though perhaps locally important, is of a much lower scale than for the other species."

Keep in mind, too, that global averages for livestock and agriculture relative to transportation are vastly different than in developed countries. That aspect is covered in LLS as well. The "more than transportation" statistic is pulled from that report without paying proper respect to the totality of the report.

Anonymous said...

Minor correction:
"The direct emissions coefficient for beef is 7.7 lbs of CO2 equivalent per pound of meat."

Obviously there are no direct CO2 emissions from cattle, only CH4 from enteric fermentation and CH4 and N2O from manure management.

n8o said...

That's it? Hell, I'm arleady there.

Moving right along...

Anonymous said...

That's it? Hell, I'm arleady there.

For an American, it would mean going from 270 pounds of meat per year to 240 pounds.

I don't think I've eaten 240 pounds of meat in 10 years, let alone 1.

George said...

I hear what you guys are saying. The 10% reduction seems extraordinarily limited.

Mike said...

As someone who seems to have a wide grasp on the future possibilities of nanotech, biotech, etc, I don't understand why you buy into this longterm forecasting of our effect on climate change. Right now if we were to employ ocean mineralization we could reverse warming right now, albeit to the detriment of the oceans. Wait 15-25 years (or 50 if we are extremely unlucky) and with a moderate control of nanotechnology we will be able to scrub massive amounts of c02 relatively cheaply. So my question is, do you believe that global warming actually poses a threat to the human species. Now I've heard Al Gore and others speak about how it will increase infectious diseases such as malaria. But in terms of monetary value we could treat 30,000 people suffering from malaria now, for the price of preventing one in the future due to global warming (by which time we will probably have an outright cure for malaria). But I am all for eating less meat though.

Anonymous said...

But in terms of monetary value we could treat 30,000 people suffering from malaria now, for the price of preventing one in the future due to global warming

Someone's been listening to Lomborg.

casey said...

I'd call it a start, if it had any possibility of taking hold among biped carnivores.

CO2 scrubbing, cloud seeding... I'm disinclined to bank on unproven technologies to offset climate change as a "quick fix" option. If they come at a later date, fine. Let's just hope it's not too late.

But there's plenty every global citizen (and government) can do to try and reduce the impact of warming, right here and now. Unfortunately, it may involve more of a personal commitment than driving a hybrid to Live Earth II.

Even if nano or other technologies (how 'bout we put a giant mirror over the Sahara to make up for the reflectivity lost from melting polar ice?) pose a solution, it still doesn't change the fact that factory farmed meat production is dangerous, unethical and frankly repellant.

Damien said...

"the fact that factory farmed meat production is dangerous, unethical and frankly repellant."

Let's keep the hyperbolic scare tactics and personal ethics out of the metaconversation... shall we?

Anonymous said...

Mike: Wait 15-25 years (or 50 if we are extremely unlucky) and with a moderate control of nanotechnology we will be able to scrub massive amounts of c02 relatively cheaply. So my question is, do you believe that global warming actually poses a threat to the human species.

Even if we could rely with certainty on future technologies being able to reduce CO2 (which would be very unwise, IMHO), the problem is that there is a severe lag between a change in temperature and its effects. So even if we were to start repairing the damage effectively in 25 years (let alone 50), things would still continue to get worse (sea level continuing to rise, etc) for a long time before they started to get better again. Carrying on with 'business as usual' now will inevitably cause significant problems for us, regardless of any future developments.

Nic Shakeshaft

Anonymous said...

This comment thread is a sad reflection of the general attitude of negativity, misanthropy and obsessive self-denial which has permeated our culture.

Eat less meat?! I like meat! Use less electricity? Using electricity lets me do all kinds of fun things! Drive less?! I want to go places. I want to live and thrive.

As a matter of *fact* there are technologies around today which would allow us to do all of the things we enjoy doing without taking serious risks regarding climate change, but I don't want to focus on that - because facts are not what motivate people. Emotions are what motivate people, and the emotion here is a big, fat guilt-trip.

According to the puritanical environmentalist movement, when the supply of something gets short, the solution is to make yourself feel really bad and stop using it, not to fix the problem and carry on enjoying life. Why do people buy this nonsense? It is a perplexing question, but I think it's all about a mass-guilt effect. Modern environmentalism persuades people by making them feel guilty, exactly the same way religion does. It creates a widespread feeling that everyone is s sinner just for being alive. "Did you know that every year you emit x tonnes of CO2!" - said in a fire-and-brimstone tone. It's almost as if your personal CO2 emissions are a physical manifestation of your sin. Once you're feeling suicidally guilty - as if you have personally killed Bambi's mother - you are offered the hessian undershirt of environmentalism. An people take it! They flay themselves day-in, day-out; recycle this, switch that off, etc, etc.

Humanity has got to where it is today by continually USING MORE. Continually expanding, growing in power and knowledge, and using the resources of this world for its own purposes. It is this fundamental lust for life - along with our intelligence - which makes us the most successful species on the planet. If we lose that will to live and thrive - surprise surprise - we will die out.

My advice to anyone who is considering eating less meat to save CO2 emissions as follows: climb into a compost bin, slit your wrists, and die. You will save an enormous amount of CO2 emissions that way, and you will create an excellent habitat for some worms.

Anonymous said...

As a matter of *fact* there are technologies around today which would allow us to do all of the things we enjoy doing without taking serious risks regarding climate change

And are you using any of them? Or are you evading the perceived "guilt trip" so successfully that you're content to do nothing at all?

Yep, thought so.

Anonymous said...

Anon @ 7:35 -- animal rights lunacy is not environmentalism, it is excessive sentimentality for chickens and fish. Please don't confound them.

Thanks for listening.