Indirect Land Use Change Emissions Research Articles

‘Low ILUC-Risk’ as a Sustainability Standard for Biofuels in the EU

‘Low ILUC-Risk’ as a Sustainability Standard for Biofuels in the EU

How robust are reductions in modeled estimates from GTAP-BIO of the indirect land use change induced by conventional biofuels?

Evidence from modeling studies shows that Indirect land use change (ILUC) emissions associated with biofuel policies play an important role in determining the climate performance of those policies, but the magnitude of these emissions for any given biofuel is contentious and subject to uncertainty. In this study, we examine the development since 2008 of the computable general equilibrium model of the Global Trade Analysis Project (GTAP-BIO) as an ILUC modeling tool. While developments to this model over the past decade have resulted in much lower ILUC values being proposed for U.S. corn ethanol and soy biodiesel by the most recent papers than in earlier work, we find that these developments have been adopted based on limited or disputed evidence. Adjustments to the model and its input parameters have strengthened the assumed role of productivity increases as compared to land use changes in meeting feedstock demand without compelling justification, while new emission factors developed for use with the GTAP-BIO results systematically underestimate ILUC emissions. We argue that the combination of these effects has introduced a significant optimism bias into the ILUC emissions results reported in more recent studies using the GTAP-BIO framework.

Regulating carbon emissions from indirect land use change (ILUC): U.S. and California case studies

As lifecycle emissions accounting becomes more widely used in policy, it is important to understand how it has been applied. This paper analyses policy-making for two U.S. fuel regulations—the federal Renewable Fuel Standard (RFS) and the California Low Carbon Fuel Standard (LCFS)—that were pioneering not only in using life cycle assessment (LCA) in performance-based environmental regulations, but especially for including emissions from indirect land use change (ILUC). The case studies in this paper focus, in particular, on the decision to include ILUC in lifecycle emissions accounting. Tracing the development of these policies shows the key role of environmental policy entrepreneurs in advocating for ILUC emissions accounting during policy formulation. Moreover, it highlights a paradox in the use of science: although ILUC policy proponents were motivated by best available research, they were also politically enabled by scientific uncertainty and lack of understanding. Understanding this political dimension of decision-making is valuable for scholars as well as practitioners facing similar decisions.

Carbon accounting and economic model uncertainty of emissions from biofuels-induced land use change.

Few of the numerous published studies of the emissions from biofuels-induced "indirect" land use change (ILUC) attempt to propagate and quantify uncertainty, and those that have done so have restricted their analysis to a portion of the modeling systems used. In this study, we pair a global, computable general equilibrium model with a model of greenhouse gas emissions from land-use change to quantify the parametric uncertainty in the paired modeling system's estimates of greenhouse gas emissions from ILUC induced by expanded production of three biofuels. We find that for the three fuel systems examined--US corn ethanol, Brazilian sugar cane ethanol, and US soybean biodiesel--95% of the results occurred within ±20 g CO2e MJ(-1) of the mean (coefficient of variation of 20-45%), with economic model parameters related to crop yield and the productivity of newly converted cropland (from forestry and pasture) contributing most of the variance in estimated ILUC emissions intensity. Although the experiments performed here allow us to characterize parametric uncertainty, changes to the model structure have the potential to shift the mean by tens of grams of CO2e per megajoule and further broaden distributions for ILUC emission intensities.

Indirect Land Use Change Debate: What Did We Learn?

In recent years, many public policies and regulations have supported the biofuel expansion in many countries. One of the main reasons for this support was concern about the environment, since biofuels, when used in place of traditional fossil fuel-based transportation fuels, lead to lower greenhouse gas (GHG) emissions. However, this argument was contradicted with the discussion on indirect land use change (ILUC) from biofuel expansion, leading to higher GHG emissions. Acknowledging this debate, we present a literature review focusing on the recent studies on ILUC and GHG emissions related to the biomass production and processing. We provide a summary of the main issues in this debate that focus on the impact of model characteristics on the GHG emissions computation, specifically those triggered by land use change.

Near-term limits to mitigation: Challenges arising from contrary mitigation effects from indirect land-use change and sulfur emissions

We explore the implications of potentially counteractive greenhouse gas mitigation responses to carbon prices and the complications that could ensue for limiting radiative forcing in the near-term. Specifically we consider the problem of reproducing the radiative forcing pathway for Representative Concentration Pathway, RCP4.5, which stabilizes radiative forcing at 4.5Wm−2 (650ppm CO2-e) under a different terrestrial policy assumption. We show that if indirect land-use change emissions are not priced, carbon prices that can replicate this pathway in the near-term may not exist. We further show that additional complexities could emerge as a consequence of the co-production of CO2 and sulfur emissions as byproducts of fossil fuel combustion.

Food, Fuel, and Climate Change

SummaryThis study evaluates the sustainability of biodiesel for transport in Thailand in terms of the availability of fresh fruit bunches (FFB) and crude palm oil (CPO) supply to satisfy the future demands for food and fuel, and the contribution of palm biodiesel to mitigating climate change if biodiesel induces land‐use change (LUC). Five land conversions including rubber, cassava, paddy field, set‐aside land, and forest land to oil palm are considered along with their displacement effects to other land types to evaluate the greenhouse gas (GHG) emissions associated with the direct and indirect land‐use impacts. The net feedstock balance reveals that the policy to expand 0.4 million hectare (Mha) for new oil palm plantations accompanied with an increase of FFB yield to 22 megagrams per hectare (Mg/ha) by 2012 would help avoid a CPO shortage; however, this increase in land use needs to be strongly encouraged. The GHG analyses show a wide range of net GHG balances compared to diesel depending on which type of land is converted and which options are used to treat the oil palm wastes. Except for forest land conversion, direct LUC emissions from converting other lands to oil palm will render benefit to the GHG balance of biodiesel. Indirect LUC emissions through crop displacements, however, will generally worsen the balance. Several recommendations are therefore suggested for sustainable palm biodiesel production in the future.

Indirect land use change emissions related to EU biofuel consumption: an analysis based on historical data

Abstract Biofuels have recently been promoted in policies as a way to reduce greenhouse gas emissions from the transport sector. However, biofuel production in itself also induces emissions directly as well as indirectly. This paper presents an explicit calculation of indirect land use change (ILUC) emissions from EU biofuel consumption. The approach includes a straightforward methodology for quantifying ILUC, based on assumptions and on data that is readily available. The calculations show that ILUC emissions alone could shift the CO2 balance for biofuels from reductions to more emissions relative to fossil fuels. This calculation is largely based on historical data, which reduces uncertainty compared to forward looking modelling approaches. However, some of the uncertainties remain. Advantage of this approach is that it can easily be reproduced, which may add to the acceptability in the domain of policy making.

Greenhouse Gas Emissions from Biofuels’ Indirect Land Use Change Are Uncertain but May Be Much Greater than Previously Estimated

The life cycle greenhouse gas (GHG) emissions induced by increased biofuel consumption are highly uncertain: individual estimates vary from each other and each has a wide intrinsic error band. Using a reduced-form model, we estimated that the bounding range for emissions from indirect land-use change (ILUC) from US corn ethanol expansion was 10 to 340 g CO(2) MJ(-1). Considering various probability distributions to model parameters, the broadest 95% central interval, i.e., between the 2.5 and 97.5%ile values, ranged from 21 to 142 g CO(2)e MJ(-1). ILUC emissions from US corn ethanol expansion thus range from small, but not negligible, to several times greater than the life cycle emissions of gasoline. The ILUC emissions estimates of 30 g CO(2) MJ(-1) for the California Air Resources Board and 34 g CO(2)e MJ(-1) by USEPA (for 2022) are at the low end of the plausible range. The lack of data and understanding (epistemic uncertainty) prevents convergence of judgment on a central value for ILUC emissions. The complexity of the global system being modeled suggests that this range is unlikely to narrow substantially in the near future. Fuel policies that require narrow bounds around point estimates of life cycle GHG emissions are thus incompatible with current and anticipated modeling capabilities. Alternative policies that address the risks associated with uncertainty are more likely to achieve GHG reductions.

Indirect land use emissions in the life cycle of biofuels: regulations vs science

AbstractRecent legislative mandates have been enacted at state and federal levels with the purpose of reducing life cycle greenhouse gas (GHG) emissions from transportation fuels. This legislation encourages the substitution of fossil fuels with ‘low‐carbon’ fuels. The burden is put on regulatory agencies to determine the GHG‐intensity of various fuels, and those agencies naturally look to science for guidance. Even though much progress has been made in determining the direct life cycle emissions from the production of biofuels, the science underpinning the estimation of potentially signifi cant emissions from indirect land use change (ILUC) is in its infancy. As legislation requires inclusion of ILUC emissions in the biofuel life cycle, regulators are in a quandary over accurate implementation. In this article, we review these circumstances and offer some suggestions for how to proceed with the science of indirect effects and regulation in the face of uncertain science. Besides investigating indirect deforestation and grassland conversion alone, a more comprehensive assessment of the total GHG emissions implications of substituting biofuels for petroleum needs to be completed before indirect effects can be accurately determined. This review fi nds that indirect emissions from livestock and military security are particularly important, and deserve further research. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd