Biofuels: Can They Save the Airlines from the Seneca Collapse?

Painting planes green is much easier than making them run on biofuels.

"Can the airlines be run on biofuels?" As it often happens, this simple question doesn't have a simple answer. First of all, it is a question that makes sense only in terms of a "sustainable" plane, that is one that doesn't run on fossil fuels. That's a major technological problem. Whereas cars can be made to run on battery-powered electric motors, the power/weight ratio of the combination is simply unacceptable for a passenger plane that could provide a performance comparable to that of current jet planes. Hydrogen planes have been proposed, but they are a nightmare for several reasons and it is unlikely that they could become practical in the short and medium term future.

That would leave only biofuels as a "sustainable" fuel that could power the current fleet of jet planes. Indeed, a small number of tests have been carried out showing that it is possible to fly planes using biofuels. But can it be done on the large scale needed to get rid of fossil fuels?

The first problem is whether biofuels are truly carbon-free. Most likely, the current fuels made from crops are not; in the sense that they involve extensive use of fossil fuels for their manufacturing. In many cases, however, even the current generation ("1st generation") of biofuels can provide a significant saving in the use of fossil fuels for the same amount of energy produced. This is the case, in particular, for ethanol produced from sugarcane in Brazil. But there is a more fundamental question is: what would be the consequences of ramping up biofuel production to the levels needed to power the current airline fleet?

In a recent paper on Nature, Rulli et al. discuss the effect of the large scale cultivation of 1st generation biofuels on various parameters of the world's economy, including the global food supply. They don't specifically examine the needs of airlines, but we can use their results for analyzing this sector. First of all, the total amount of jet fuel consumed in the world is reported to be 6,000,000 barrels per day. It corresponds to about 7% of the total world combustible liquids production. We may consider this value as approximately the fraction of transportation energy used by airlines since crude oil represents 93% of the total energy used in transportation.

Rulli et al. estimate that if we were to arrive at a 10% reliance on biofuels for the world's transport, that would leave food for no more than 6.7 billion people and, since the current world population is about 7.6 billion people, almost one billion people would starve. Now, since the airlines consume about 7% of the world's transport energy, feeding the airlines with biofuels would move us dangerously close to the threshold that would lead to killing a large number of people for the purpose of keeping planes flying.

Of course, these data are for first-generation biofuels. There is much enthusiasm for second and third generation biofuels from cellulosic plant tissues or algae which, theoretically don't impact on the food supply. Sure, but today the production of these fuels is non-existent or at best negligible. How long will it take to ramp up their production to the levels we are discussing here? And are we sure that they will work as promised?

The problem, here, is not just a technological one. We are dealing with a complex system, the world's economy coupled with the planetary ecosystem. In these systems, you can't change just one thing and leave all the rest unchanged. Once we start to produce biofuels on a very large scale, it becomes extremely difficult to stop at a certain threshold. If we have a product and a market for it, both tend to expand and it is nearly impossible to stop the expansion of something that generates a profit.

That would bring big problems, to say the least. Rulli et al. estimate that arriving to supply 1st generation biofuels in an amount corresponding to 20% of the transport energy would leave no more than 4.4 billion people alive in the world. That is, it would kill some 3 billion people. Or, if dealing with 2nd or 3rd generation biofuels, it would lead to whatever disaster generated by the appropriation for humankind an even larger fraction of the planetary photosynthetic activity than it is done today. The ecosystem has limits, after all.

Unfortunately, it is unlikely that ethical considerations would affect decisions in this field. The system is made in such a way that if producing fuels for the rich is more profitable than producing food for the poor, the system will produce fuels, even though that implies killing billions of people. So, we can only hope that biofuels will turn out to be too expensive even for the rich; but that may not be the case. With so much research and development ongoing, production costs might be lowered enough to turn biofuel into an effective weapon of mass destruction (and I wouldn't be surprised to discover that this is one of the reasons why biofuels are promoted so aggressively in some quarters).

Or, more simply, we may hope that the Seneca Collapse of the world's economy will take care of the "airline problem" once and for all. As I said many times, the Seneca Cliff is not a problem, it is an opportunity. In this case, it could lead us to develop better transportation technologies; more efficient and more benign for the ecosystem - although probably slower. But that's not a problem, either. It is an opportunity to travel only when you need to, and to enjoy the trip, too!




 Some further data on the extent of land needed for the cultivation of biofuels for airlines. 

First of all, the total amount of jet fuel consumed in the world is reported to be 6,000,000 barrels per day . It corresponds to about 7% of the total world combustible liquids production. Now, we need to compare the values measured in barrels with the needs of the airlines, measured in liters. A barrel contains 159 liters, so 159*6=1000 makes about 1 billion liters/day, or 3.6x10^11 liters/year. Let's now consider the most efficient biofuel production: ethanol from Brazil's sugarcane. It can produce 6000 liters/ha per year  http://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/1754-6834-1-6  Note that ethanol is not as energy dense as jet fuel. It has only about 70% of the energy density of gasoline http://www.afdc.energy.gov/fuels/fuel_comparison_chart.pdf. Which means that the airlines would consume 3.6*10^11/0.7 = ca. 500 billion liters of ethanol/year. 

So, assuming that the whole production of Brazilian ethanol is dedicated to airplanes, we would need more than 80*10^6 hectares (eighty million hectares). The total arable land in Brazil is reported to be: 75 Million ha. http://www.tradingeconomics.com/brazil/arable-land-hectares-wb-data.html It means that the whole agriculture of Brazil should be dedicated only to produce fuel for the airlines. 

That is, of course, absurd, but it is also true that the world's total arable land is = 1,407 x10^6 ha (https://en.wikipedia.org/wiki/Arable_land), about 20 times the area available in Brazil. So, the airlines would need only about 5% of the total which is, by the way, just slightly larger than the global arable area used for biofuel production today  (about 4%)  http://www.nature.com/articles/srep22521. But note also that not all the arable land has the same good productivity as the land used for sugarcane production in Brazil, so the real fraction needed would have to be considerably larger than 5%, probably still less than 10%. How many people would starve if we were to arrive to that, it is impossible to say. 

Why biofuels are not a good idea

If you have always been thinking that biofuels are not a good idea, this book by Mario Giampietro and Kozo Mayumi will tell you exactly why.

Last year, I was engaged in a public debate on energy with a high level senior official of the Italian government - a "technocrat" if you like to use this term. When I expressed strong doubts about biofuels as a source of energy, his reaction was aggressive. He attacked me personally, hinting that I was on the payroll of the oil industry, since it is obvious that they don't like biofuels. He added that this fact was proven by the statements against biofuels issued by the Saudi ministry of petroleum. Besides, he said, speaking against biofuels is a way to prevent the poor of Brazil from reaping the goods that globalization will bring to them as soon as the biofuel world market of ethanol will be liberalized.(*)

Debates are always a learning experience, this one was no exception. One of the things I learned is that technocrats are just politicians who don't have to worry too much about their constituency. As politicians, their instinct in the debate is to go immediately for the personal attack; it is a strategy honed to perfection through thousands of years of political debate. My opponent applied it without worrying too much about the contradiction implied in accusing me of being on the payroll of the oil industry - think that I have spent the past ten years preaching the arrival of peak oil!

Another thing that I learned from that debate is how, by now, the biofuel industry has become so big that it is already politically incorrect to speak in public against biofuels. If you do that, you are bound to take plenty of flak; which is what happened to me. If you want to survive this kind of attacks, you must be very well prepared on the subject. For this purpose, you may find a lot of help in the recent book "The Biofuel Delusion" by Mario Giampietro and Kozo Mayumi. If you are unsure about why exactly biofuels are the disaster that they are, this book will explain to you that on the basis of a rigorous analysis and plenty of data. It is unfortunate (actually, it is a scandal) that it is so expensive; almost 70 dollars for a copy. But if you are engaged in the energy debate, it is a good investment.

Biofuels are a complex matter and Giampietro and Mayumi use almost 300 pages to eviscerate it in all its aspects. The main point of their analysis is based on fundamental physics: the efficiency of photosynthesis is low and the result is that the areas needed for cultivation are large. If we are thinking of amounts of biofuels comparable to the present needs for transportation, the task is simply unthinkable: there would be no space left for food production. As the authors flatly state at page 128 of the book, "Full substitution of fossil energy with agro-biofuels is impossible."

The large area needed is only one of the problems with biofuels. More in general, agriculture is a good technology for producing food, but it is terribly expensive in terms of the resources it requires. It needs land, water, fertilizers, pesticides, mechanical work; all supplies that normally come from fossil fuels. Taking all that into account, the EROEI (energy return for energy invested) of biofuels is generally low; unless the invested energy is supplied by low cost human labor, as it is the case for Brazilian sugar cane. Apart from Brazil, the need of an energy subsidy in the form of fossil fuels makes biofuels unable to deliver their promise of being a "sustainable" technology. They can't help us in reducing our dependency on fossil fuels nor in reducing the emission of greenhouse gases in the atmosphere.

Of course, the biofuel story is more complex than that and Giampietro and Mayumi examine the whole spectrum of possibilities in their book. Are there better biofuels? Or, perhaps, ways of using the present form of biofuels in a more effective way? Yes, of course; there is the promise of "second generation" fuels (cellulosic ethanol) and the possibility of cultivating marginal areas, unsuitable for food production. But the physical factors of the problem don't change much and, right now, biofuels and conventional agriculture are already competing for land and resources. One of consequences may be the increase increase in food prices that we have been seen during the past few years.

In the end, what do we want to do, exactly, with biofuels? Do we really think that the way to solve our energy problems is to use an inefficient technology to support an already inefficient transportation system? The only explanation I can think of for so much emphasis on biofuels is that, once a bad idea is implemented, it starts to gain momentum and then it becomes nearly impossible to stop.

At this point, you may wonder how the debate with my technocratic opponent ended. Well, I was tempted to use his own tactics and accuse him to be on the payroll of the biofuel lobby. But I am not a politician and I didn't do that; also because I saw that it was not necessary. If you have some experience in speaking in public, you soon develop a sixth sense about what your audience thinks. In this case, it was clear to me: the audience was with me, not with my technocratic opponent. They just didn't buy the idea that biofuels can solve the world's fuel problem without starving anybody - to say nothing about the idea that globalization will make the Brazilian peasants rich. Did he sense that, too? I can't say. A few months later, he got an even higher level position in the new "technocratic" Monti government in Italy.



* By the way, the recent abolition of the government subsidies on corn ethanol in the US is probably a good thing, but it does not at all end the government support on biofuels, as you can read in this interesting article by Mike Sheldon on "The Oil Drum." Note, in particular, that the abolition of subsidies comes together with the abolition of the tariff on ethanol imports from Brazil and that could make ethanol cheaper than it was with subsidies! And it remains to be seen how that will affect the Brazilian peasants. 


See also: The Earthscan's page on "The Biofuel Delusion"
Mario Giampietro's page at the Universitat Autonoma de Barcelona