Biofuels and land use conversion I

Food vs fuel issues, and agriculture and use of agricultural products generally, are so complicated that they have emergent properties. We can think about them most easily by intentionally oversimplifying. So here goes.

Before the recent increase in expectations for biofuels as a solution for energy/global climate change problems, human appropriation of net primary productivity (HANPP) had reached a kind of equilibrium. (HANPP is the amount of biosphere bounty humans skim off the top, before flora and fauna get to dine.) Agricultural production has increased roughly in synch with population growth, mostly through improved plant breeding and agronomic practices. This has meant that large increases of farmland area haven’t been as necessary as they might have been without yield increases. Population growth is slowing, and most concern is about the consumption of material goods by people, not the number of people per se.

The difference now, post-biofuels, is that each gallon of biofuel consumption is equivalent to additional increases in population. A gallon of ethanol (the ethanol itself, not including production) contains about 90 MJ (21,500 kcal) of energy, enough energy for 10 days of a 2000 Calorie/day diet. For a gallon of biodiesel, then numbers are more like 140 MJ or 33,000 kcal — enough for over 2 weeks of human power.

I haven’t examined new reports from Europe about biofuels and indirect land use conversion, but increasing use of biofuels without decreasing overall energy use unavoidably leads to increasing land area in agriculture. New land is not being formed, so land use change is inevitable. This only makes intuitive sense. Of course there will be improvements — a recent news story suggested that limited replacement of corn with miscanthus (a hybrid grass) would have a variety of benefits, including increased ethanol production. However, there is a hard theoretical limit to possible increases.

By the way, use of non-food crops and materials for biofuels isn’t an improvement, from a biosphere/HANPP perspective. The problem is energy consumption, not biofuel production.

I think the real question is, what are the implications of apparently changing attitudes toward biodiesel for our regional biodiesel economy? How will we respond if and when European-style indirect land-use conversion concerns are raised here? See the next post for a map showing global HANPP for food and non-food crops — it will suggest why Europeans may be more sensitive to land use conversion issues than those of us in the US Northwest.

In the old days, I hoped that conceptual linkage between biofuels and food would cause people to examine their own energy consumption, rather than blame biofuels. Unfortunately, that doesn’t seem to be happening.

About Steve

Steve Verhey, Ph.D., is Executive Director of the Cascadia Carbon Institute (CCI). CCI is a nonprofit think tank dedicated to educating policymakers, agriculturalists, industry, and the public about sustainability, agriculture, renewable energy, and global climate change. Dr. Verhey has been involved in sustainable agriculture and energy issues for over 20 years. Trained as an agricultural scientist, he received his Ph.D in plant molecular biology and biochemistry from Oregon State University and his M.S. in Botany from the University of Washington. He recieved his B.A. in Biology from Reed College. He has served as a consultant for a variety of national and international renewable energy projects for companies such as Boston Consulting Group, HSBC, Portland General Electric, Algenol, Harvest Partners, Biofields SAPI de CV, Guggenheim Partners, Viking Global Investors, and Bank of America-Merrill Lynch. He is co-founder and Chief Managing Manager of Central Washington Biodiesel LLC, a rationally sized biodiesel startup, and served as Chief Science Officer for Bioalgene, an algae-to-fuel startup.
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One Response to Biofuels and land use conversion I

  1. John Ousterhout says:

    Biofuels that are derived from human or animal feed as co-products may not represent an unavoidable increase in agricultural land. For example, converting the undigestible carbohydrates in corn to ethanol prior to feeding it to cattle does not reduce it’s food value, but does increase it’s profitability to the producer and farmer. The material in the feed corn that could have been made into fuel passes through the cow, to end up as manure. This breaks down into nutrients the plants can use, which is a utility. If ethanol were made as a co-product, the CO from combustion would be absorbed by the plants, providing a different but comparable utility. The comllex carbohydrates can either be recycled through the soil, or through the atmosphere. One path provides fuel, the other doesn’t.
    Somewhat similarly, Canola grown “for biodiesel” also results in high-protein, highly digestible cattle feed, once the oil has been extracted. If so much of our agricultural energy is devoted to feeding cattle, and if a co-product of cattle feed can be used for transportation fuel, then there is no additional land necessary. Without extracting the fuel co-product portion of cattle feed, we use other sources for an equivalent amount of fuel. Those sources are already having undesirable effects, which should be compared to the “food or fuel” debate.
    A point missing from virtually every food debate is the question of how many people we ought to be feeding, rather than how to feed any arbitrary number of people using only finite resources that are showing indications of unsustainable overproduction.