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Biofuels Are Not a Green Alternative to Fossil Fuels

This blog post was originally published in The Guardian on January 29, 2015.

Powering cars with corn and burning wood to make electricity might seem like a way to lessen dependence on fossil fuels and help solve the climate crisis. But although some forms of bioenergy can play a helpful role, dedicating land specifically for generating bioenergy is unwise. It uses land needed for food production and carbon storage, it requires large areas to generate just a small amount of fuel, and it won’t typically cut greenhouse gas emissions.

First, dedicating areas to bioenergy production increases competition for land.

Roughly three-quarters of the world’s vegetated land is already being used to meet people’s need for food and forest products, and that demand is expected to rise by 70 percent or more by 2050. Much of the rest contains natural ecosystems that keep climate-warming carbon out of the atmosphere, protect freshwater supplies, and preserve biodiversity.

Because land and the plants growing on it are already generating these benefits, diverting land—even degraded, under-utilised areas—to bioenergy means sacrificing much-needed food, timber, and carbon storage.

Second, bioenergy production is an inefficient use of land.

While photosynthesis may do a great job of converting the sun’s rays into food, it is an inefficient way to turn solar radiation into non-food energy that people can use. Thus, it takes a lot of land (and water) to yield a small amount of fuel from plants. In a new working paper, WRI calculates that providing just 10 percent of the world’s liquid transportation fuel in the year 2050 would require nearly 30 percent of all the energy in a year’s worth of crops the world produces today.

The push for bioenergy extends beyond transportation fuels to the harvest of trees and other sources of biomass for electricity and heat generation. Some research suggests that bioenergy could meet 20 percent of the world’s total annual energy demand by 2050. Yet doing so would require an amount of plants equal to all the world’s current crop harvests, plant residues, timber, and grass consumed by livestock–a true non-starter.

Third, bioenergy that makes dedicated use of land does not generally cut greenhouse gas emissions.

Burning biomass, whether directly as wood or in the form of ethanol or biodiesel, emits carbon dioxide just like burning fossil fuels. In fact, burning biomass directly emits a bit more carbon dioxide than fossil fuels for the same amount of generated energy. But most calculations claiming that bioenergy reduces greenhouse gas emissions relative to burning fossil fuels do not include the carbon dioxide released when biomass is burned. They exclude it based on the assumption that this release of carbon dioxide is matched and implicitly offset by the carbon dioxide absorbed by the plants growing the biomass.

Yet if those plants were going to grow anyway, simply diverting them to bioenergy does not remove any additional carbon from the atmosphere and therefore does not offset the emissions from burning that biomass. Furthermore, when natural forests are felled to generate bioenergy or to replace the farm fields that were diverted to growing biofuels, greenhouse gas emissions go up.

That said, some forms of bioenergy do not increase competition with food or land, and using them instead of fossil fuels could reduce greenhouse gas emissions. One example is biomass grown in excess of what would have grown without the demand for bioenergy, such as winter cover crops for energy. Others include timber processing wastes, urban waste wood, landfill methane, and modest amounts of agriculture residues.

Using so-called second-generation technologies to convert material such as crop residues into bioenergy has a role to play and avoids competition for land. A challenge will be to do this at scale, since most of these residues are already used for animal feed or needed for soil fertility, and others are expensive to harvest.

There are good alternatives to bioenergy made from dedicated land. For example, solar photovoltaic (PV) cells convert sunlight directly into energy that people can use, much like bioenergy, but with greater efficiency and less water use. On three-quarters of the world’s land, solar PV systems today can generate more than 100 times the usable energy per hectare as bioenergy. Because electric motors can be two to three times more efficient than internal combustion engines, solar PV can result in 200 to 300 times as much usable energy per hectare for vehicle transport compared to bioenergy.

One of the great challenges of our generation is how the world can sustainably feed a population expected to reach 9.6 billion by 2050. Using crops or land for biofuels competes with food production, making this goal even more difficult.

The world’s land is a finite resource. As Earth becomes more crowded, fertile land and the plants it supports become ever more valuable for food, timber and carbon storage—things for which we don’t have an alternative source.


Agreed, only wastes should be converted to fuels, and there are plenty of wastes to backup solar and wind, provide long haul transport fuels and chemical feed stocks.

Do agree, technology should give a hand in converting waste into energy more efficiently, it also applies for solar and wind.

There are several problems with this article. The first the headline. It should read "Not all biofuels ..." but that of course would get less coverage. Lumping all biofuels / bioenergy into a single group is just simply wrong. Considering the business and ecology of biofuels from a single vantage point, i.e. a western 'developed' nation perspective is also simply wrong.

Lets look at your statements one by one.

First - 'dedicating areas to bioenergy production increases competition for land'. Surprise surprise, dedicating areas to urban development does the same, to HEP, to paper and pulp? So there is a competition for land, this is not unique to any human activity. And I agree that using good agricultural soils for biofuel production makes no sense.

The 'land and the plants growing on it are already generating these benefits, diverting land—even degraded, under-utilised areas—to bioenergy means sacrificing much-needed food, timber, and carbon storage.' Right here you need to get out of the office more and get some real world experience. Here is one from Chingola, Kabwe, Nampundwe and several other towns in Zambia. Having been mined, overburden heaps and pits remain unvegetated. For over 40 years in some instances. So they are producing nothing useful, just dust, flooding, albedo - a whole list of negatives. Why have they not been revegetated with natural timber trees ? Simple because there is a surplus of the forest products you refer to and timber doesn't cut the mustard in terms of revenues even when the trees can grow under the harsh conditions. So clearly revegetation with a biofuel tree like Pongamia makes sense here. Located in peri-urban areas, vital jobs, domestic energy, useful by-products, reduction of FOREX. To hell with the detailed LCA carbon emissions. After all this part of the world still has 60% of its natural forests and is not responsible for climate change.

Second - bioenergy production is an inefficient use of land. Well see above. If it isn't and ca't be used for anything else then...what is the alternative ?

The authors would suggest a solar power plant. Really. How is this going to benefit the average Zambian youth, in terms of jobs for example ? With panels made in China ? A few labouring jobs during construction, while foreign contractors and technical teams do all the highly paid jobs ? Then what ? Washing panels to get all the dust from the pit and the mine overburden ?

Contrast this with a N-fixing, carbon sequestering, soil rehabilitating (to reduce flooding and water retention), tree. Plantation establishment jobs, plantation maintenance jobs, product processing jobs, by-product processing jobs, value adding jobs (for health and biopesticide products). Inefficient ? Really?

Third - "bioenergy that makes dedicated use of land does not generally cut greenhouse gas emissions."Again, see point 1. What do you mean by bioenergy? You cannot simply lump them together. Again, weak understanding of what is driving land use change and what the end point of this change is.

Let's take another look at reality, and lift our eyes beyond the model, the spreadsheet. Forest is being lost in Zambia to charcoal production and subsequently converted to low input low output agriculture. Meanwhile, all diesel, all petroleum is imported. I do not have the total FOREX cost numbers at hand but it is large. Meanwhile, most people use and prefer to use charcoal.

So the forest lost to charcoal is not being replaced with forest. The carbon is not being re-sequestered. Much of the land that is being deforested is not suitable for agriculture. It may work for a few years, but will degrade and cause off-site problems as a result of erosion, loss of water infiltration capacity and the like. So replanting with a highly productive biofuel generating tree that provides these basic ecosystem functions AND generates wealth, offsets fossil fuel production does make sense.

Then let's consider how this could then interact with the existing small scale farming to raise yields. Well if the tree produces organic fertiliser from waste seedcake with significant N, P, K and micro-nutrients, also providing much needed Soil Organic Matter then this is a win win. Much better than inorganic fertilisers which are made from fossil fuels (natural gas - which by the way is imported).

You seem to assume that once cleared the forest will regenerate. It wont it will be converted to small scale agriculture as there are no other jobs, not because the food is needed domestically. Provide alternative jobs from a land use activity that generates higher revenues in a forest based system that resequesters the carbon, and provides invaluable by-products to the remaining agricultural land is a no brainer.

Finally, the much touted food vs fuel debate. This is totally irrelevant to this part of the World (Zambia). It is entirely relevant to the US. We are entirely food independent and still have cleared land to spare, which is not as you may think regenerating largely because of fires. If a country like Zambia can produce domestically biofuels, charcoal substitute, organic fertilisers, biopesticides and high value health products from land that would otherwise degrade, is degrading and power communities to improve livelihoods then of course this is a good alternative to imported fossil fuels and indeed much touted solar. Can I intercrop with solar ? Will it fix nitrogen for me, provide organic fertiliser. Tell me, just when do you expect to see the first solar powered car or tractor making it's way here. For the transition period, for the next 35 to 60 years, selective use of land for high yielding N-fixing, local economy stimulating by-product producing bioenergy trees.

I started by stating that the problem is this article. Its full of journalistic generalisations, western 'developed' world perspective and sensational headlines which just do not cut the mustard in todays highly context dependent circumstances. Sadly it's the third time I've seen it pop up on facebook, so this misinformation is spreading.

I will now find the working paper to understand the assumptions that must underly this working paper. i'm sure most of these are very justifiable as WRI are experts in their field. The problem is you cannot do these types of calculations to make such bland general statements without getting into the finer social, environmental and economic detail of many many different locations across the world where the assumptions may not hold up. I expect to read a bit of a pointless study. Let's see.

Thanks for your well researched reply, and the info which relates to your country - good read. I think you will enjoy this link, have a look at the the flow chart. This gives you the best of both Worlds, shows what can be done. The only problem is that the NSW Government will not force the fuel companies to comply with it's 10% E10 fuel mandate. Manildra has trouble getting rid of this ethanol because of this. The waste starch was being disposed of, by flushing it into the waterways.
Brian Wells

In the US, 16 tons of corn/maize is produced per hectare, in Europe about 12, in Africa just over 1. A sustainable level for Africa would be around 10. Losses pre- and post-harvest amount to more than 1/3 of production.

Many debates around biofuels forget this, focusing on how there will be more mouths to feed and seemingly believing that advancements in agriculture will be small or none. That may be true if future investments are not forthcoming, but with biofuels (or other cash crops), the needed investments are potentially available. Also, biofuels (as opposed to for instance coffee, tobacco or golf courses, that all use more space than biofuel cultivation in Africa), help reduce oil dependency which creates huge holes in the budgets of most poor countries, which means the governments can't adequately support their citizens. FAO recently said that food vs fuel is over, we now need to find the best food AND fuel solutions. This is a quest that needs all available expertise, so get down from the fence!

Ethanol fuel programs -- whether from corn in the US or sugarcane in Brazil -- have invariably involved heavy subsidies (overt and, sometimes, at least in Brazil, hidden) from the general population to the vested interests involved on the production side. It is no coincidence that mid-western farming states punch above their weight in the Senate and in presidential primaries: as a result, biofuel subsidies are considered well nigh untouchable......

Well written and I appreciate your wonderful insights. You have come up with valuable and thoughtful arguments which every human being should think about it. Using crops or land for bio fuels is not at all an efficient step to feed our growing population. I seriously doubt about our sustainable future by 2050. This will put a bad impact on our global warming. Technology should be made more advanced to convert wastes into energy as it is the ultimate solution to save our lands.

While I agree with the author's opinion on our the current approach to biofuels, what are the possible disadvantages of turning to cyanobacteria (algae) for an energy alternative? The processes require a fascinatingly small amount of landmass and water. Facilities can occupy otherwise unusable land - requiring only water, CO2 and sunlight. The bacteria can even be programmed to produce specific chemicals including various fuels and prescription drugs.

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