'Serious and Dangerous Deficiencies' in IPCC Biofuel Recommendations

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By far the weakest of this year’s reports from the Intergovernmental Panel on Climate Change is the report on Mitigation. The latest challenge comes in a letter from five leading climate scientists to the IPCC chair that identifies “serious and dangerous deficiencies” in its discussion of biofuels, and asks that parts of it be withdrawn.The main body of the letter, without the authors’ extensive footnotes, is below. The full text can be read HERE, and the IPCC’s Mitigation report is online HERE. Thanks to Jim Roland of Grain for making this available.

30 October 2007To Dr Rajendra Pachauri Chairman, IPCC

Dear Dr Pachauri,

Concerns over notes on biofuels in IPCC AR4 Mitigation report and SPM

First of all, we note that climate change and the human contribution to it are most pressing issues that require the greatest attention.

We note further the important role the IPCC has played in demonstrating the strength of scientific agreement on various aspects of, and matters surrounding, climate change.

We also welcome, this year, the on-line pre-publication of the full draft AR4 Mitigation report plus corrections.

However, we consider that there are serious and dangerous deficiencies in the notes on biofuels both in the AR4 Mitigation SPM and Transport chapter in their present form; and further that inquiries as to the basis of a key claim made have not been responded to.

With accumulating evidence of multiple adverse consequences for emissions, humanity and biodiversity from unbridled biofuel expansion, we have grave concerns that the respective parts of IPCC publications will become used to justify further adverse developments, and delays in rescinding already erroneous decisions.

The following are our key concerns. Where recent published work has been referenced, the issues raised are not new to science.

1. Chapter 5 (Transport), p325 mentions that alternative fossil fuels will tend to lead to increased emissions. It should have been made clearer on this page that replacing petroleum fuels with electricity, hydrogen and biofuels all also carry risks of being environmentally counter-productive.

2. Chapter 5, p325 states that mitigation potential of biomass fuel is uncertain as it may be limited by its sustainability in “massive scale”. On p344 it is elaborated that the “biofuel potential…is limited by the amount of available agricultural land” not required for other uses, and that “the production of biofuels on a massive scale may require deforestation and the release of soil carbon”.

Although this may be strictly true in literal terms, the notes omit to state that in practice, even at a small scale, cultivation of biofuels often will take fertile land away from agricultural use, and thus lead to land-use change emissions, as the market-place encourages the world farming frontier to expand into forests and other often carbon-rich ecosystems to accommodate. This is currently leading variously to major damage to biodiversity, irregularities in land acquisition and other human rights abuses, water pollution and stress on water resources in addition to the land disturbance emissions.

For example, in Europe the use of rapeseed oil for biodiesel in Europe has led to increased palm oil imports to compensate, a principle recognized by palm oil producers. The growing world bioenergy-related market for palm oil is a major part of the speculative incentive for deforestation for new plantations around the tropics, with major attendant land-use change emissions from soils and often from vegetation, as well as human displacement, the slaughter of orang-utans and other losses of very considerable biodiversity.

The emissions associated with palm oil plantations on thick tropical peat are particularly colossal. A major recent study estimated that producing 1 tonne of palm oil on peatland emitted between 10 and 30 tonnes of CO2 from drainage decomposition, excluding fires associated with land clearance, which in South-East Asia’s peatlands were currently emitting more than twice as much CO2 as that from drainage decomposition. Peat swamp forests are the only major land area not yet populated in SE Asia. Increased demand for palm oil will accelerate the conversion of peat swamp forests into plantations and thus will accelerate the release of greenhouse gases and the destruction of biodiversity hotspots.

In the United States, increased maize plantings and their use for ethanol have contributed to price rises for many food commodities, forcing up the incentive for deforestation to grow soya and other commodities in South America and elsewhere . Poignantly, 2007 has seen exceptionally severe fires in the soya-growing areas of South America. US maize plantings are also displacing virgin prairie with attendant carbon releases.

Forest displacement is reinforced when pastoralists and smallholders who have lost land to advancing monocultures move to forest edges to continue in such livelihoods.

3. Chapter 5 cites an estimate of the expected savings from biofuel substitution: p326: “The use of current and advanced biofuels would give an additional reduction potential of another 600– 1500 MtCO2-eq in 2030 at costs <25 US$/tCO2 (low agreement, limited evidence).” This is derived further in, pp. 365-366, based on the IEA report Energy Technology Perspectives 2006 and an overall estimate of a 25% CO2-eq emissions saving from biofuel substitution.

Yet such an estimate does not make allowance for land-use change emissions, whether direct or indirect, from such an expansion of biofuels, which in many instances could take decades or centuries to recoup, as for example the Concawe study and this year’s UN report on bioenergy have correctly noted.

The danger, then of a major outlay of emissions and cumulative radiative forcing effects far exceeding the hypothetical mitigation from biofuels by 2030, should be noted by the IPCC, and highlighted prominently beside any projection of hypothetical gains.

It should further be mentioned that even if deforestation could somehow be halted, there is a major likelihood that the combined effects of the rising world dietary footprint (from diversifying diets and rising population) and more widespread crop failures and droughts associated with climate change will cause the scope to produce biomass or biofuel crops to fall by 2030, if not very much sooner.

4. Ch 5, pp343-344 admits that one reason for uncertainty in well-to-wheels emissions balance calculations is “how to handle the effects of alternative uses of land” and states “Typical examples are shown in Figure 5.10.” Yet the examples in Figure 5.10 make no allowance for land-use change effects.

5. There is no mention of the key principle that for a given quantity of land, usually several times more emission mitigation (CO2-eq) per hectare can be achieved by either (a) growing solid biomass crops (tall grasses or short rotation coppice), or using agricultural surpluses or waste cut biomass, to replace coal, or (b) simply reafforesting the same land, than biofuels for transport. These non-transport land-uses are likely to remain superior for mitigation for many years to come.

For example, the Concawe Well-to-Wheels study reports that typical EU-based biofuel crops for transport will only yield 1/10 -1/5 the emissions savings per hectare of biomass crops for stationary applications (compared with wood used for coal replacement). Second generation ethanol (also based on wood) returned only 1/5 the emissions mitigation yield of using wood as a standard.

This point should be prominently made to policy-makers, who in announcing targets for biofuels for transport have prioritized that land-use OVER the above far greater emissions mitigation potentials, in addition to other issues (e.g. world food supply, water resources, conserving natural forests, grasslands and wetlands).

It is insufficient merely to mention, as Ch 5 does (p344) that biomass for stationary applications tends to deliver emissions savings at a lower price than biofuels for transport.

6. Ch 5, p344, notes that “The biofuel potential is limited by…The amount of available agricultural land (and in case of competing uses for that land) for traditional and dedicated energy crops;” followed by a reference to release of soil carbon.

This statement does not warn clearly enough of the seriousness of the danger of expanding the agricultural frontier, as stated in the Concawe Well-to-Wheels report: “We deliberately did not consider the expansion of arable area onto other land, notably pasture and forest. Apart from the societal resistance, such change in land use would be likely to release large amounts of carbon from the soil, negating any benefit of the energy crops for decades to come.”

7. Ch 5, p342 notes “Cellulosic crops… may be grown in areas unsuitable for grains and other food/feed crops and thus do not compete with food.” This is incorrect (whether or not the word “do” was intended), since such land is often used as pasture for livestock and is currently under stress in many locations,

It continues: “the energy use is far less, resulting in much greater GHG reductions than with corn and most food crops”. This is inaccurate since cellulosic ethanol involves more fermentation than conventional ethanol, and distillation as before, although cellulosic ethanol may outperform conventional ethanol in some scenarios.

In contrast, for example, the use of inefficient solar cells to recharge inefficient batteries in hybrid cars is at least 100 times more energy-efficient than any current land-use system for producing ethanol, and solar cells can be sited in desert.

8. Ch 5, p379, 5.5.5 notes that “implementation [of biofuels in the transport sector] would generally have positive social, environmental… side effects.”

This is a highly contentious claim in view of the widespread conversion of biodiverse tropical forests and grasslands into biofuel monocultures, associated human rights abuses, pollution from fertilizer run-off and plant residue burning, and more widely, reactive nitrogen emissions and potential stresses on water supplies, soils and mineral fertilizer sources.

There are further dangers from biofuel crop plants acting as invasive species and from the escape of genetically modified higher yielding plants and organisms adapted for use in ligno-cellulosic technology.

The rise in world food prices increases food stress and hardship for the urban poor of the Global South, and is straining food aid budgets, though benefiting many farmers.

More intense land use tends to reduce local biodiversity, and the spread of monocultures will overall impact negatively on tropical forests and other natural and semi-natural habitats, their resilience, ecosystem services such as nutrient cycling and climate moderation, and the conservation of species.

This is not to argue against all bioenergy, but present policies of the EU, US and elsewhere are leading to a huge range of adverse outcomes and very poor resource stewardship though involving considerable subsidy. There is surely scope for decision-makers to design a better fiscal regime for bioenergy.

In this context it will certainly not suffice to label or ‘certify’ some biofuels as ‘sustainable’, as has been suggested in Europe, on the basis of estimated emissions savings that do not take into account the displaced land-use change consequences if they are sourced from land that would otherwise have been used to produce food.

9. Ch 5 only refers to the Brazilian sugar-ethanol industry in glowing terms: p344: “the highly advanced state of Brazilian sugar farming and processing”, and “The example of ethanol in Brazil is a model.”

Such descriptions are ill-fitting in view of the widely reported areas of poor practice associated with the Brazilian sugar-cane industry including employee health and safety, smoke from ethanol industry; and the controversial expansion of sugar-cane into the Cerrado and development beside the Pantanal wetland (although a recent declaration of restriction on this is welcomed).

Indeed, the Co-ordinating Lead Author Prof. S Kahn Ribeiro of the Federal University of Rio de Janeiro cannot be unaware of these issues.

Sugarcane production in Brazil also causes more soil erosion than any other crop grown in Brazil.

10. The Summary for Policy Makers, table SPM.7, p20 refers to “biofuel blending” as a policy, measure or instrument “shown to be environmentally effective… in at least a number of national cases” -a Brazilian tabled amendment.

This claim is of extreme concern, since no justification for it appears elsewhere in the report, and, bearing in mind the issues set out above, we are unaware of the studies that can be used to justify such a claim. Furthermore, inquiries as to the basis for this claim were made to the Co-ordinating Lead Author Prof. S Kahn Ribeiro in May, and have not been replied to.

There should be no such non-transparency in public science. We call on you now to publish the basis for this claim or withdraw it.

If the analysis of the US ethanol programme by Farrell et al (2006) is being used in the basis, this paper makes no allowance for the resultant land-use change emissions (see 2. above), and itself cautions:”several key issues remain unquantified, such as soil erosion and the conversion of forest to agriculture”; and other elements of its basis for estimating emissions savings are contested, see for example Patzek (2006)and Crutzen et al. (2007). Earlier work has noted that corn production causes more soil erosion than any other crop grown in the US.

In summary, many notes in the Mitigation report give the impression that biofuel expansion is generally a good way to proceed, with inadequate reference to the dangers and pitfalls; the SPM further claims that biofuel blending measures have had proven environmental benefit, yet the Co-ordinating Lead Author concerned has ignored inquiries as to the basis of this claim.


Professor David Pimentel, Cornell University
Professor Tad Patzek. University of California, Berkeley
Professor Dr. Florian Siegert, RSS GmbH, Munich office
Dr. Mario Giampietro, ICREA Research Professor Universitat Autònoma de Barcelona
Professor Helmut Haberl, Alpen-Adria-Universität Klagenfurt