Last week I was in the State of Iowa for a ten-day intensive class on agriculture. Iowa is quite the agricultural powerhouse -- around 20 percent of the country's corn and 30 percent of our hogs (pork) come from this one state. One of our major topics of discussion was the extremely high amount of energy inputs that are needed to grow the crops here. Petroleum-based fertilizer is the driving force behind large-scale agriculture; the past century of farming has stripped the soil of nutrients required to grow crops, and synthetic fertilizers must be used to replace these nutrients each year. A farmer loses about one-third of his earnings to these fertilizers. Looking at these agricultural petroleum inputs has reminded me about how incredible fossil fuels are.

 

An interesting way to look at it: The huge majority of our energy, and all of our energy reserves (such as oil and coal), are from the stored energy of Earth's once-living organisms. A researcher at Stanford University named Jeffrey Dukes calculated how much stored energy from plants it took to produce the fossil fuels we use for most of our energy today. According to his assessment, the amount of fossil fuels used in 1997 alone is equivalent to Earth's complete production of biomass, or "Net Primary Production" for 400 years. Of course, burying plants under the earth for hundreds of thousands of years is not the most efficient way to make fuels, so it is probably a good idea to look at how much biomass it would take us to supply current demand. Dukes also did that calculation; he estimated that it would take a 50 percent increase in the amount of Net Primary Production that we use currently for food and fuel to replace oil and coal. Everybody grow corn in their backyard?

 

Oil and coal are the most concentrated, portable and easily harvested forms of energy we have discovered, and they certainly aren't being replaced very quickly (Dukes says it takes about 89 metric tons of plant matter/gallon). Our massive consumption of fossil fuels has brought on the destabilization of our climate and fueled the destruction of our ecosystems, but it is worth it to step back every once in a while and appreciate just how amazing petroleum really is. From it we can create practically anything -- from plastics to fertilizers that grow our food. Since the invention of the steam engine, we have doubled the amount of people who live on planet Earth; the world has experienced growth that is not comparable to anything else in human history. Energy has never been and probably will never be as cheap as it has been for the past two centuries; we've certainly got a challenge to figure out what comes next.