Wrong Question: Can Biofuels Be Carbon Friendly?

The Science Insider blog last week hosted an interesting debate between Tim Searchinger, Princeton visiting scholar, and John Sheehan, of the Institute on the Environment at the University of Minnesota, regarding the recent policy proposal in the pages of Science by Searchinger et al. to “fix” the carbon accounting of biomass for bioenergy and biofuels in U.S. legislation and the successor to the Kyoto protocol, by giving credit only to biomass that can be managed in such a way as to sequester additional atmospheric carbon in the soil. As Searchinger puts it in the recent debate, “bioenergy only reduces greenhouse gases if it results from additional plant growth or in some other way uses carbon that would not otherwise be stored.”

To be sure, use of bioenergy can only reduce the overall level of greenhouse gases in the atmosphere by sequestering carbon in the soil (in root systems). And yes, individual biofuel or bioenergy producers could use only new biomass that has recently pulled carbon from the atmosphere (although other environmentalists may differ on that) or biomass that would otherwise be left to decay and emit the stored carbon anyway. The question then is whether there is enough of this type of biomass to meet energy needs.

But that is not the point of the current Kyoto protocol or of U.S. cap-and-trade legislation. Their shared goal is to reduce overall GHG emissions, over time, ideally lowering the cap until emissions reach equilibrium.

Searchinger cites recent modeling studies to say that not employing his fix to global carbon accounting “would lead to the loss of most of the world’s natural forest because clearing those forests for bioenergy becomes one of the cost-effective means of complying with laws to reduce greenhouse gas emissions.” However, the fossil fuel industries are certain to receive allowances under the U.S. legislation. Employing a carbon accounting model that treats biomass as equivalent to fossil fuel would definitely make continued reliance on fossil fuel the cost-effective alternative.

Another interesting response to the Searchinger et al article comes from Geoff Styles of the Energy Collective, who extends the carbon accounting argument to electric vehicles. All alternative energy sources can be opened up to particular scrutiny. What is needed is a truly accurate and balanced accounting of fossil fuel use to compare these arguments.

The only other political option would be to drastically cut use of all energy. Models do project that the current worldwide economic recession has brought about a reduction in climate emissions by cutting energy use.

Searchinger does note that biomass and biofuels have the potential to balance greenhouse gas emissions – depending on land management. A better question here is whether his models can show that fossil fuel use also has the potential to balance greenhouse gas emissions with proper land management.

Compounded Climate Accounting Errors

Timothy Searchinger, visiting scholar at Princeton University, Dan Kammen of the University of California Berkeley, David Tilman of the University of Minnesota and other authors from the Environmental Defense Fund published an interesting new proposal in the Policy Forum section of Science magazine today. The argument put forward is that “Replacing fossil fuels with bioenergy does not by itself reduce carbon emissions, because the CO2 released by tailpipes and smokestacks is roughly the same per unit of energy regardless of the source.”

The premise behind this proposal is that the world is facing such a great need to reduce carbon emissions that future sources of energy and biofuels cannot make use of any currently sequestered carbon. Maybe… but there’s a perverse consequence of using this logic. Fossil fuels are a source of sequestered carbon. If you then say that all existing biomass is an untouchable source of sequestered carbon, you are essentially counting that sequestration as a benefit of having used fossil fuels for the past 150 years.

The logic is particularly tortured when a foregone sequestration penalty is attributed to biofuels when none is counted for petroleum.

There is much in the paper to agree with — particularly in recognizing carbon sequestration benefits from improved land management practices and energy crops. And certainly, the challenge of climate change is so great that implementing best practices for carbon sequestration is a necessity.

But a proposal that attributes carbon sequestration in trees as a plus in the accounting of fossil fuel use is counterproductive.

Opportunity Costs

The Washington Post this week reported on a carbon-credit proposal being put forward by Ecuador for consideration in UNFCCC Climate Change Talks. Ecuador is asking for carbon credits in exchange for leaving undisturbed one-fifth of its petroleum reserves, which are located beneath a protected national park that is part of the Amazon rainforest.

The proposal is similar to one put forward by Brazil last August, called the Amazon Fund, which asks foreign countries to donate money for investment in Brazilian businesses that would conserve the Amazon rather than cut it down – rubber production, for instance, rather than timber, cattle, and agriculture.

The Intergovernmental Panel on Climate Change recognizes natural and managed forests as potential carbon sinks, but not untapped petroleum reserves.

Ecuador’s proposal highlights one of the more obscure calculations in the life cycle emissions of biofuels included in the EPA’s proposed rule — namely “foregone sequestration.” Because natural forests store more carbon than managed agricultural land, biofuels are assessed an opportunity cost stemming from conversion of forest or grassland to agriculture. This is not actual carbon released from the forest or grassland, but a penalty for not preserving a carbon sink (or, in the case of grassland, not converting it to a forest).

The EPA has assumed and applied to biofuels a constant rate of foregone sequestration over a period of 80 years. In fact, the cumulative calculated emissions of corn ethanol include only this opportunity cost after the 20 year mark. The rate is equal to nearly half the calculated emissions of the gasoline baseline. The inclusion of this factor more than doubles the calculated emissions per acre of converted Brazilian forest land assumed to be caused by U.S. biofuel production.

A similar opportunity cost should arguably be applied to petroleum, particularly if Ecuador’s proposal moves forward and the international community recognizes untapped petroleum reserves as potential carbon sinks. In the case of Ecuador, this opportunity cost might include both the emissions that could have been avoided by leaving fossil carbon in the ground and the deforestation caused as roads, pipelines, and drilling sites are cleared from the Amazonian forest.

Europe to Study Indirect Land Use

The European Parliament on Dec. 17 adopted amendments to the Renewable Energy Sources Directive, raising targets for production of biofuels but at the same time setting strict sustainability standards to monitor and reduce greenhouse gas emissions from the use of road transport fuels. The Parliament’s adopted text makes clear that it intends to calculate climate change emissions from international land use, but that the science is not currently available to do so:

(11) In calculating the greenhouse gas impact of land conversion, economic operators should be able to use actual values for the carbon stocks associated with the reference land use and the land use after conversion. They should also be able to use standard values. The work of the Intergovernmental Panel on Climate Change is the appropriate basis for this. That work is not currently expressed in a form that is immediately usable by economic operators.”

The text also includes this assessment of the risk of indirect land use change and the need for an accurate measurement:

(18) Even if biofuels themselves are made using raw materials from land already in arable use, the net increase in demand for crops caused by the promotion of biofuels could lead to a net increase in the cropped area. This could be into high carbon stock land, in which case there would be damaging carbon stock losses. To alleviate this risk, it is appropriate to introduce accompanying measures to encourage an increased rate of productivity increases on land already used for crops; the use of degraded land; and the adoption of sustainability requirements, comparable to those laid down in this Directive for EU biofuel consumption, in other biofuel-consuming jurisdictions. The Commission shall develop a concrete methodology to minimise greenhouse gas emissions caused by indirect land use changes. In doing this the Commission shall analyse, on the basis of best available scientific evidence, in particular, inter alia, the inclusion of a factor for indirect land use changes in the calculation of greenhouse gas emissions and the need to incentivise sustainable biofuels which minimise the impacts of land use change and improve biofuel sustainability with respect to indirect land use change. In developing this methodology, the Commission should inter alia address the potential indirect land use change effects of biofuels produced from non-food cellulosic material and from ligno-cellulosic material.”

The agreed upon amendments to Directive 98/70/EC include a two-year study of indirect land use change that is to include methods to ensure that sustainable biofuels avoid causing land use change:

7d. (6). The Commission shall, by 31 December 2010, submit a report to the European Parliament and to the Council reviewing the impact of indirect land use change on greenhouse gas emissions and addressing ways to minimise this impact. This report shall where appropriate be accompanied, in particular by a proposal, based on the best available scientific evidence, containing a concrete methodology for emissions from carbon stock changes caused by indirect land use changes, ensuring compliance with this Directive, in particular Article 7b(2).”

Annex IV. Rules for Calculating Life Cycle Greenhouse Emissions from Biofuels, includes the calculation of GHG reductions for different types of biofuels without land use change.

Note that the U.S. Energy Security and Independence Act also called for a National Academies study of indirect land use impact, to be completed within 18 months of the law’s enactment. That study has not been funded.

Discounting the Future of Biofuels

It appears that global leaders’ faith in energy technologies that can reduce greenhouse gas emissions compared to oil is waning, particularly for biofuels, as reported in GreenInc. Respondents to the survey, which included 1,000 environmental experts, ranked energy conservation and efficiency technologies as having the greatest potential impact, both short- and long-term.

Some 44 percent of respondents also said they expect that the current economic crisis will hinder progress toward an effective international climate agreement. Katherine Sierra, World Bank Vice President for Sustainable Development, noted, “The development challenge is to accelerate or maintain robust economic growth in poorer countries while also dealing with the impacts of climate change. The financial situation is no justification for postponing action on climate change. Climate change is not waiting, so we cannot wait either.”

These sentiments appear to be relevant to a rather arcane debate about the application of a discount rate to greenhouse gas reductions. The debate over the discount rate may become a more prominent issue, since it is a feature of the EPA’s Advanced Notice of Proposed Rulemaking on Regulating Greenhouse Gas Emissions under the Clean Air Act. It also appears that the EPA would apply a discount rate to greenhouse gas emission reductions in the life cycle assessments of biofuels, under the RFS.

A discount rate is used in cost-benefit analyses as a way to measure current costs against the value of future benefits. In applying the theory to reductions in greenhouse gas emissions, the idea is that the benefits are for future generations and on a worldwide scale, while the costs of deploying reduction technologies are paid by specific individuals today. Further, there is uncertainty about which technologies will provide the greatest benefit and investing in one may come at the expense of investing in others.

Gary Becker, the noted economist and University Professor at the University of Chicago, explains it by saying,

Future generations would be better off if the present generation, instead of investing the $800 billion in greenhouse gas-reducing technologies, invested the same amount in capital that would be available to future generations.
“Common sense also dictates that one recognizes that technologies will be much improved in the future, including technologies related to improving health, income, and the environment. A positive and non-negligible discount rate is the formal way to recognize the importance of these and related considerations.”

But environmentalists have traditionally opposed the use of a discount rate for environmental benefits. Lisa Heinzerling, a law professor at Georgetown University, responded to the use of the discount rate in EPA’s ANPR on her own blog page, saying, “Discounting is a technique used to reflect the idea that events occurring in the future are not as important as events occurring now. By using a fairly low discount rate, EPA avoided the severe trivialization of the future that often attends use of discounting.”

Elsewhere, though, she took issue with the use of any discount rate for environmental benefits:

We have said that the federal government places too low a value on human life; that it devalues the future through discounting; that it fixates on the costs and dismisses the benefits of environmental protection; that it slights the worth of effects that cannot be counted.
“Cost-benefit analysis is a deeply flawed device that has never been the environmentalist’s friend. It impedes rather than aids understanding of the concrete consequences of regulations. It would behoove the next president — and all who value environmental protection — to do more than fiddle around the margins of old debates, and to question whether a decision-making framework that can stare environmental catastrophe in the face and declare it ‘efficient’ is really the best we can do.”

Even proponents of including international land use change calculations in the EPA’s life cycle assessment of biofuels may take issue with the application of a discount rate to the calculation, or at least a high rate. Mark Delucchi is a research scientist at the Institute of Transportation Studies at UC Davis and developer of the Lifecycle Emissions Model. He notes that in the context of indirect land use for biofuels, “the discount rate determines the value of the reversal of the initial change: a zero discount rate gives it a value equal to that of the initial change; a high discount rate gives it no value.” And, “If the discount rate is very large, then we don’t care at all about the future reversion of land use and reversal of the initial change in emissions; we care only about initial change in land use and emissions.” In other words, using the discount rate in this context assumes that the carbon debt attributed to biofuels due to land use change is never paid back, which would be incorrect. Delucchi argues that a positive discount rate applied to the life cycle analysis should be reduced to reach zero over time.

However the debate on discount rate plays out in policies on greenhouse gas reductions and the Renewable Fuel Standard, the theory does seem to reflect the preferences of environmental leaders – that we not use biofuels today but wait for a better technology to come along in the future. The risk for them is that everyone’s faith in the ability to produce clean energy and reduce greenhouse gas emissions will start to fall.