A bushel of new studies suggest that production of corn ethanol not only makes global warming worse but contributes heavily to water pollution. One reason is the heavy doses of nitrogen fertilizer that American farmers dump on corn fields.
A study by Paul J. Crutzen, a Nobel Prize-winning chemist, argues that some biofuels release more greenhouse gases than they save because nitrogen fertilizer produces nitrous oxide, a greenhouse gas that is 300 times more potent than carbon dioxide as an atmospheric insulator.
The study estimates that corn ethanol produces between .9 and 1.5 times the global warming effect of conventional gasoline.
Crutzen suggests that to get an environmental benefit from ethanol, it must be refined from crops that use little fertilizer and can be harvested without using large amounts of energy. Both of those criteria rule out corn or rapeseed, the primary feeder crop for biofuel in Europe.
This study is hardly the first knock on corn ethanol. Various others have concluded that it takes more energy from oil to grow and harvest corn and refine ethanol (a substitute for gasoline) than the ethanol itself produces. At best, it's a push.
So ethanol is a boon to American agribusiness, but not the environment. That's the real reason why farm states and Congress are in love with ethanol subsidies. Unfortunately, the farm bill being debated now in the Senate will only make matters worse.
Besides, diverting corn from feeding humans to feeding cars is driving up the cost of eating around the world.
Biofuels subsidized by billions of tax dollars will push food prices 20-40 percent higher by 2020, according to the Food Policy Research Institute. Rising corn prices already are contributing to malnutrition in developing countries.
On top of all this, the National Research Council warns that projected increases in production of corn for ethanol will harm both water quality and supplies.
To be blunt about it, unless you're Monsanto or Archer Daniels Midland, making fuel from corn is a spectacularly dumb idea.