Indirect Land Use Changes
Indirect Land Use Changes (ILUC) are conversions from one land use type into another (such as from forest to cropland) that are caused by changes in the production level of an agricultural commodity in another, often far away location. They are cloesly related to leakage effects. ILUC gained attention both in scientific research and in public discussions due to concerns that crop based biofuels might accelerate deforestation in the tropics. This could diminish or offset the benefits of a reduced consumption of fossil fuels.
While there is scientific consensus about the existence of ILUC effects, their quantification is still challenging. Differences between model estimates and the uncertainties involved in the ILUC factors derived from them complicates the consideration of ILUC in politics. Due to these uncertainties, inclusion of ILUC factors in assessments of bioenergy crops has received strong criticism from interest groups but also from within the scientific community. However, ignoring ILUC effects will underestimate the potential for environmental damages and might even result in perverse outcomes of environmental policies.
The term Indirect Land Use Changes (ILUC) refers to changes in the production level of an agricultural commodity that cause land use changes in another, often far away location (IPCC, 2014). Land use changes in this context are conversions from one of the six IPCC land use categories into another (Forest land, Cropland, Grassland, Wetlands, Settlements, Other lands), usually from forest land to grassland or from forest land or grassland to cropland (IPCC 2006). ILUC gained attention both in scientific research and in public discussions with regard to potential effects of crop based biofuels. Searchinger et al. (2008) argued that American biofuel production have a net negative effect on the global climate because they trigger deforestation in the tropics and thereby cause greenhouse gas emissions that outweigh any savings from the reduced reliance on fossil fuels.
The introduction of biofuels and the policy support they received in industrialized countries resulted in changes that re-distributed a share of the global harvest towards this novel purpose (Searchinger et al., 2008). If a large area of cropland is no longer used to produce a specific commodity, then this affects the relationship between supply and demand for this commodity and increases the commodity’s price. Higher prices in turn motivate conversion of other land use types (often forest or savannah) into cropland to produce this commodity (Ahlgren & Di Lucia, 2014; Villoria & Hertel, 2011, Wicke et al., 2012). Because many agricultural goods are traded internationally, land use changes can occur in other world regions, with global markets creating a tele-connection (Yu et al., 2013).
However, ILUC can also occur non market-mediated in the form of a competition for land resources. For example, the conversion of rangeland into cropland to produce biofuels (direct land use change) can cause a migration of cattle herders to other locations where they clear forests to create new rangeland (indirect land use change) (Lapola et al., 2010).
Indirect land use changes can have a significant impact on the economic, social and environmental dimensions of sustainability (Ahlgren & Di Lucia, 2014). Within the policy arena, awareness of the problem of ILUC due to biofuel production and of the greenhouse gas emissions resulting from ILUC is well-established. In the US, ILUC accounting was incorporated into the federal Renewable Fuel Standard in 2007 and into California’s Low-Carbon Fuel Standard in 2009 (Breetz 2017). In 2015, the ILUC calculations for the Low-Carbon Fuel Standard were revised (Leland et al., 2018). In Europe, Directive 2015/1513 was passed in 2015 to account for ILUC effects from bioenergy and biofuels. The directive includes provisional values for greenhouse gas emission from ILUC for three feedstock groups and amends the Renewable Energy Directive (2009/28/EC) and the Fuels Directive (98/70/EC).
While there is scientific consensus on the existence of ILUC effects, their quantification is very challenging with various modelling approaches resulting in very different ILUC factors (Finkbeiner, 2014). This is not only due to technical difficulties, but also a result of conceptual differences (Flysjö et al., 2012). The resulting uncertainties make it difficult to consider ILUC in politics, where precise estimates of ILUC factors are sought for (Ahlgren & Di Lucia, 2014). Uncertainties are the basis for strong criticism from interest groups but also from within the scientific community (Finkbeiner, 2014).