Sunday, November 16, 2008

Why math matters...

My largest complaint with the agrarian movement, now closely linked with the Food Movement personified by Michale Pollan, is they weave brilliant logical scenarios but don't (or can't, I suspect) do the math to support their positions.

A classic example has to be the Rise and Fall of Food Miles.  Once again, operating on a seemingly unassailable logic that food grown closer is better because it appears to require less energy to transport and produce, proponents seduced the innumerate masses in the US and around the world.

While scientists around the world have been pointing out that there is no basis for this charming idea in reality, a cascade of studies may help to finally unwind this food myth.

One of the best summaries is by Ron Bailey at Reason:
In the United States, a 2007 analysis found that transporting food from producers to retailers accounted for only 4 percent of greenhouse emissions related to food. According to a 2000 study, agriculture was responsible for 7.7 percent of total U.S. greenhouse gas emissions. In that study, food transport accounted for 14 percent of the greenhouse gas emissions associated with agriculture, which means that food transport is responsible for about 1 percent of total U.S. greenhouse gas emissions.

Food miles advocates fail to grasp the simple idea that food should be grown where it is most economically advantageous to do so. Relevant advantages consist of various combinations of soil, climate, labor, capital, and other factors. It is possible to grow bananas in Iceland, but Costa Rica really has the better climate for that activity. Transporting food is just one relatively small cost of providing modern consumers with their daily bread, meat, cheese, and veggies. Desrochers and Shimizu argue that concentrating agricultural production in the most favorable regions is the best way to minimize human impacts on the environment.

Local food production does not always produce fewer greenhouse gas emissions. For example, the 2005 DEFRA study found that British tomato growers emit 2.4 metric tons of carbon dioxide for each ton of tomatoes grown compared to 0.6 tons of carbon dioxide for each ton of Spanish tomatoes. The difference is British tomatoes are produced in heated greenhouses. Another study found that cold storage of British apples produced more carbon dioxide than shipping New Zealand apples by sea to London. In addition, U.K. dairy farmers use twice as much energy to produce a metric ton of milk solids than do New Zealand farmers. Other researchers have determined that Kenyan cut rose growers emit 6 metric tons of carbon dioxide per 12,000 roses compared to the 35 tons of carbon dioxide emitted by their Dutch competitors. Kenyan roses grow in sunny fields whereas Dutch roses grow in heated greenhouses.  [More]

What this argument has suggested to me is we really don't understand our energy usage at all. Few of us really comprehend how energy dense coal and oil are compared to any other source, for example. Led astray by the vision of wind turbines capturing "free" energy, we gloss over the output compared to one stinky ol' coal plant. (Good rule of thumb: each 2 GWatt coal plant =  1000 wind turbines)

BTW, this same energy density problem is why I remain super-skeptical of cellulosic energy.

But lest we industrial farmers get smug about our hard-nosed approach to worldly energy decisions consider Bailey's closing graf:
Desrochers and Shimizu demonstrate that the debate over food miles is a distraction from the real issues that confront global food production. For instance, rich country subsidies amounting to more than $300 billion per year are severely distorting global agricultural production and trade. If the subsidies were removed, far more agricultural goods would be produced in and imported from developing countries, helping lift millions of people out of poverty. They warn that the food miles campaign is "providing a new set of rhetorical tools to bolster protectionist interests that are fundamentally detrimental to most of humankind." Ultimately, Desrochers and Shimizu's analysis shows that "the concept of food miles is...a profoundly flawed sustainability indicator."
I'm not so sure our farm policy is safe from the economic turmoil as we currently believe.  Too many other needs are now in the handout line, and liberals can change their minds.


Ol James said...

A funny thing...I haven't heard from the "CO2 Squad" The amount of CO2 that the plants take in...wonder why??? Oh yeah, I forgot...they can't make a buck off of it.
If the President Elect and his cronnies want to talk bad about Farmers and those in the AG sector I say quit feeding them. Don't think they would want to confront a hungry mob, one way or another.....
Whadda ya think???

Anonymous said...

I think the "Local-vores" movement is more about knowing where your food came from and its quality, as opposed to the amount of energy required to get it to you.