Hemp – a good idea, but not a great one

I just read yet another article about how industrial hemp could be a replacement for crude oil.  If you read non-mainstream media enough you will run into such articles. The author touted hemp’s benefits as a replacement fiber for wood pulp, cotton, and petrochemical fibers. Fine. Our ancestors wrote on hemp paper and wore hemp clothes as they raised hemp sails with hemp ropes. The U.S. government promoted the domestic growth of hemp for rope fiber during WWII, when we lost our source of so-called Manila hemp in the Phillipines.

Then I read this paragraph:

"If all the diesel engines today were converted to use hemp biodiesel, you could wipe out world hunger while providing a natural balance to global warming" says Paul Stanford of the Hemp and Cannabis Foundation, which has worked to end marijuana prohibition and restore industrial hemp.”

This kind of hyperbole drives me nuts. Here’s the blanket statement from the Minor Heretic on biofuels. If it involves…

• Growing something
• Converting that something to a fuel
• Pouring that fuel into a fleet of 230 million vehicles
• Each vehicle weighs over a ton and carries an average of 1.2 passengers at highway speeds for an average of 13,000 miles a year

…then it is not going to work. There is just not enough land, water, or nutrients to do the job. That’s not hyperbole; it is an acknowledgment of the limitations of natural systems.

Let’s just do the math on biodiesel from hemp seed. I am going to wave my magic wand and turn all 230 million registered vehicles in the U.S. into 40 mpg diesels, all converted to run on straight vegetable oil. That is a big wave of the wand, but I don’t want anyone claiming that I didn’t give hemp oil biodiesel every chance. I am also going to assume, as was suggested by one comment on the article, that the best variety of hemp will produce 8,000 pounds of seed an acre, a stunning 13 times the productivity of standard industrial hemp. According to that miracle-hemp comment this would translate into 300 gallons of hemp oil per acre.

At an average of about 13,000 miles per year, our fleet racks up 2,990,000,000,000 miles annually. That’s almost 3 trillion. At 40 mpg, that would require 74,750,000,000 gallons of hemp oil. At 300 gallons an acre, that would require 249, 166,666 acres of arable land. Call it an even 250 million acres.

There are 400 million acres of land under cultivation in the U.S. right now. Even under this bizarrely optimistic, “magic” scenario we would have to transfer over half of that to hemp fuel production. Either that, or we would have to find 250 million new acres of arable land when we are already growing crops on heavily irrigated semi-desert. Also consider that this is unrelenting cultivation, without fallowing or rotation, year after year. When one does the basic math, the ridiculous nature of biofuel-as-panacea claims becomes obvious.

By all means, let’s legalize and promote industrial hemp. It could be a much more benign fiber crop than cotton. (I like the feel of the cloth. It has great “hand”, as the tailors say.) It could even displace some petrochemical use. Give it a few years and the “petro” in petrochemicals could be launching past $140 a barrel, so I’d welcome a few alternatives.

Let us not, however, jolly ourselves into thinking we can continue driving behemoths as usual, except with bio-whatever in the tanks. I myself drive a vehicle that is converted to run on both petro-diesel and used vegetable oil. Nevertheless, I don’t con myself into thinking that it is a solution for the mass of Americans. I don’t even see it as a long-term niche solution.

The answer that will be forced upon us by the hard dictates of geology and physics is a life of limited mobility. What long distance mobility we will have will be slower, more expensive, and much less convenient than what we have today. We’ll do a lot of walking, bicycling, and just plain staying home. We need to stop fantasizing about some green magic bullet and start the long and difficult transition to life without the private automobile.