Biofuels and Butterflies

Perspective teaches us that life is about tradeoffs.  Here is one that is not so obvious.

Any Master Gardener (or third grader) can tell you that pollinators are vital to our food supply. So when I hear people fuss about monarch butterflies, I always wonder if it’s because they are superior pollinators. It turns out they probably are not.  The National Wildlife Foundation tells us:  “Bees are well-known pollinators, but over 100,000 invertebrates—including butterflies, moths, wasps, flies, and beetles—and over 1,000 mammals, birds, reptiles and amphibians, act as pollinators.”  All pollinators are struggling, but why the emphasis on monarchs?

This website describes monarch butterflies as charismatic mini-fauna, small animals that stir positive feelings in us when we see them. They are pretty and easily identifiable, so we feel a special bond with these butterflies, hence the fascination with them and the handwringing over their gradual disappearance.

Reasons for their decline include logging in the Mexican overwintering zone and the uses of broad-spectrum insecticides on farms and in personal gardens. Inability to adapt to some factors of climate change may also contribute.  But that particular site puts the bulk of the blame on the disappearance of their breeding habitat. “The caterpillars eat only one plant: Milkweed. And milkweed has been vanishing from the landscape.”

Especially corn farmers are tilling every last inch of soil available, thereby eliminating milkweed that once grew around the edges of their fields.  The site links this to our demand for the cheapest food possible, which they say leads farmers to “keep their fields weed free, kill milkweed, and – by extension – kill monarchs.”

But that’s not exactly correct. Farmers do not grow more corn because we insist on low food prices any more than Saudi Arabia pumps more oil because we like low gasoline prices.  The problem is not on the supply side; it’s the high demand for corn brought about by rules requiring that ethanol be mixed with gasoline to reduce our dependence on foreign oil.

Some argue that the ethanol rules are also designed to reduce the amount of carbon dioxide released into the atmosphere.  Burning ethanol or other biofuels is “cleaner” than burning gasoline on a gallon-for-gallon basis, but they are not as efficient. Burning a gallon of gasoline provides more energy than a gallon of ethanol, so when everything is accounted for the mpg-to-mpg difference is insignificant in terms of CO₂ emissions. Foreign oil is the primary reason.

Now we get to the trade off.  Most think: monarchs are good, and biofuels are good, but drilling for more oil off shore or in Alaska is bad. But doing so could eliminate our dependence on foreign oil resulting in less pressure on the farmers to till every available square foot leaving more milkweeds as a breeding habitat for monarch butterflies.

Perspective reminds us that we can’t have everything exactly the way we want it – butterflies and biofuels.  Compromises are sometimes necessary.

Note:  Near where I live (that evil) Monsanto promotes planting milkweed in highway medians.