Truth in Fuel Labeling?

Most people know that our personal health is affected by what we eat – i.e., how we fuel our bodies. And now there's growing awareness that our planet's health is affected by how we fuel our cars.   The main culprit is carbon dioxide emissions, and in that respect some fuels are unhealthier than others.

In the case of food, we understand that the type of food - chicken, lamb, corn, spinach(!), etc. - doesn’t fully determine how healthy it is.  That depends on a full “ground-to-stomach” accounting – how the food is grown, processed, and distributed. Did that chicken grow up eating processed nutrients, chemicals, and hormones in a dark, crowded chicken factory, or strutting around in a sunlit barnyard eating natural, pesticide-free food? It makes a difference.

Likewise for automotive fuel. One can easily get the impression that carbon emissions (and therefore planetary health) are determined simply by the type of fuel – gasoline, diesel, electricity, ethanol, hydrogen, etc. – but it’s not that simple. Valid comparisons require a full ground-to-tank accounting, i.e., including the emissions from fuel production, distribution, and use.  Such comparisons are not easy; to get a sense for the complexity, look here, and here. 

Whether an electric vehicle is good for the environment depends on how the electricity is produced – from renewable energy sources like solar and wind, good; from burning coal, not so good. Likewise, whether ethanol is healthier than gasoline depends on how the ethanol is made. With today's methods, sugar-based and switchgrass-based ("cellulosic") ethanol are healthier (less carbon-intensive) than corn-based ethanol, and healthier than gasoline.  Meanwhile, it's not clear that corn-based ethanol is healthier than gasoline, although improved methods of production may yield corn-based ethanol that's clearly less carbon-intensive. 

So what’s a consumer to do? In the case of food, those who care are informed by such truth-in-labeling, ground-to-stomach designations such as “certified organic” (far from perfect, but better than nothing). What about fuel? For those who care, could fuel be labeled to indicate ground-to-tank carbon emissions?

There are obvious practical problems in doing so, but in principle it's possible. For example, all fuel could be encoded with information about carbon emissions – chemical markers in liquid fuel, specialized modulation in electricity, etc. And fuel-dispensers could display carbon information just as they display changing prices. Could a practical system be developed, perhaps involving regional, manual labeling? Would anybody care?

Perhaps some consumers would pay more for healthier fuel. You are what you eat.  We are what we burn.