Life cycle thinking is increasingly popular for policy uses, especially in the field of bioenergy.

Life cycle analysis, or LCA, has become a familiar tool used to understand and improve processes or answer environmental impact questions. When something was needed to evaluate the possible climate effects of bioenergy decisions, LCA was the logical choice. The ability to calculate greenhouse gas (GHG) savings or to improve processes has encouraged its use in meeting targets, selecting energy options, and determining policy by helping assess possible outcomes of policy decisions.

From its origins in energy analysis, LCA has evolved to become a wider ranging tool, playing an increasing role in regulatory compliance and policy decisions. In the last decade or so, driven by its adoption for use in biofuels policy in the United States and European Union under the aegis of the Energy Independence and Security Act (EISA) and the Renewable Energy Directive (RED), LCA has expanded from a retrospective tool for particular projects to a predictive one for wider policy. It is now used to help frame and answer forward-looking questions such as policy impacts on land use change and energy supply. This approach may have origins in the bioenergy arena, but it is already beginning to transition into other sectors.

The impact categories inventoried in an LCA have grown along with its expanded use. Though greenhouse gas balances now dominate the LCA landscape, it has also been used to assess other impacts, such as those of a particular product or policy on resources, water quality, and health. Biodiversity and other impacts are being added, and the tool is opening up to include impacts on social factors such as jobs. These will make up a growing portion of LCA’s future. As the tool matures, the range of impacts will expand to add impact metrics that reflect societal values in a globally integrated world.

Bioenergy LCA and policy shape each other

Policy decisions are expected to account for the long-term public good and ideally to set the optimal path for planning purposes. To do that, “optimal” has to be defined, taking into account factors such as employment, security, and other drivers. This is the link between LCA and policy: policy defines optimal, and LCA compares the possible impact of options being considered. Just as policy decisions affect multiple scales, impacts occur on multiple scales and in different places. Policy instruments put this concept into operation.

Traditionally, LCA has been used to measure the impact of products or systems that are already in existence. Thus the boundaries defining the study area are tight, containing only direct impacts from production, use and disposal; this is known as attributional LCA (ALCA). ALCA frequently contributes to policy and regulation directly or indirectly through key considerations, such as GHG emissions.

However, using LCA as a more predictive tool to inform policy requires the inclusion of wider impacts and a broader boundary. Typically this is done by building on environmental or economic models to include market-mediated environmental and regional or local social impacts. This expands LCA from evaluating effects directly attributable to the project to evaluating those it may indirectly cause. This approach, focusing more closely on the potential consequences, has attracted much discussion in the academic arena and developed into “Consequential LCA”(CLCA).

Carbon emissions associated with direct and indirect land use change have been the highest profile of these issues, although there are others under the heading of “indirect” or “rebound” effects. Direct land use change is land converted for the siting of the bioenergy facility or for the supply of the feedstock it actually processes.

Indirect land use change, in contrast, may occur when some of an inelastic commodity is allocated to another use – in this case, a feedstock used for bioenergy. Since demand for that commodity is perceived as fixed, the market may encourage production of that commodity elsewhere to replace the diverted amount. Most commonly this is discussed with grain based biofuels, for example, corn ethanol. This is treated as a particular concern because the new land conversion is generally thought to occur in countries perceived to have less stringent environmental protections. The conversion of the land to grow the replacement commodity releases greenhouse gases, which are then allocated as an indirect consequence of the project that diverted the commodity in the first place.

Implicit and explicit values and decision criteria (along with filtering assumptions made in the scenario design process) strongly influence the outcomes of comparative studies. Such value judgments are the purview of policy, not the rubric used for comparison. Unfortunately, these value judgments are seldom stated explicitly. Without an explicit statement and subsequent ranking of priorities, it is hard to select from a suite of many different options, because “optimal” depends on those rankings.

Driver Policy results Impact on LCA development

Policy makers are required to consider a wide range of issues such as economics and employment (e.g. rural agricultural policy links to bioenergy). Risks not normally associated with LCA must be considered.

Life cycle thinking used more frequently in policy and planning.

LCA methodology is expanded, and/or linked to other analysis tools.

There is a need to determine “best” options for energy mix.

Wider energy policies and directives (e.g. RED, EISA) are introduced, setting targets for renewable energy, including bioenergy.

LCA moves from attributional to consequential to try to address some of the wider questions.

Bioenergy policy is increasing the amount of biofuel/energy used/imported in many developed countries.
Competition for resources crosses national boundaries and sectors (in bioenergy, energy and agriculture/

Policies with embedded LCA requirements emerge (e.g. Renewable Transport Fuel Obligation, Fuel Quality Directive, Renewable Fuel Standard, Low Carbon Fuel Standard). Sustainability standards proliferate.

LCA calculators, tools and data develop to calculate GHGs. These have varying degrees of consistency, accuracy and transparency.
Shared resource governance tools expand.

National and regional targets for bioenergy specifically, or as a component of a renewable portfolio.

Increased movement (import/export) of bioenergy feedstock.

Discussion about land use change and indirect land use change emerges quickly; linking to wider move from attributional to consequential LCA.

Increased understanding of international market intersections, geopolitical factors, and projection of climate change are used to improve policy-driven integrated assessments.

Energy/Bioenergy policy shape markets and supply, and these effects are incorporated in standards and policy instruments.

Mechanistic models connecting to traditional LCA develop. Wider discussion around emerging knowledge and data supporting long-term energy policies (and bioenergy calculations) increases awareness of uncertainty in LCA; active research and method development continue.





Differing needs and issues for LCA and policy

The RED and EISA began the widespread acceptance of LCA within the bioenergy policy arena, creating concrete LCA-bounded categories. The inclusion in these instruments of emissions from indirect land use change assigned to the biofuels has generated substantial debate and controversy. It has spurred evolution in both policy and method.

Even though the various forms of LCA can effectively answer many policy questions, they come from different places. So policy needs and LCA issues aren’t always in sync. When we don’t remember that, we risk getting incomplete or illusory answers.
The time over which a comparison is made also influences decisions. For example, over a short time period, conversion of land for biofuels may result in a smaller benefit in greenhouse gas reduction or even an increase, but the cumulative greenhouse gas reduction of displacing fossil-derived fuels over a longer time horizon may be much larger. Likewise, perennial bioenergy feedstocks, like some grasses, increase soil carbon annually, and will at some point in time surpass the release from conversion. The mechanisms for these processes are still open areas of research, both physically and in terms of impact assessment.
Because LCAs can be used to estimate the effects of a particular situation, it is tempting to use them to try to assess risk. This suggests a certainty in the situation occurring, but risk depends not only on the potential impact of an event but also the likelihood of its occurrence. Separate evaluations, outside the scope of LCA, of the odds of a risky event happening are needed to inform planning and mitigation strategies.

The needs of policy makers often differ from what is possible using LCA. The tradition of LCA emerging from energy analysis and air and water quality accounting leads to the belief that all LCAs can be completed with certainty. But in order to include broader impacts that cannot be directly attributed to a particular actor, certainty must be compromised for breadth.

The distinction between attributional and consequential LCAs is a crucial one. Between a particular project and societal responsibility for consequences that touch multiple sectors is a wide expanse. It is the drive to fill this gap that will continue to shape LCA’s future as part of a suite of impact assessment tools to guide policy.

Sampling of relevant bodies, policies and standards

EPA/ US Environmental Protection Agency. Early adopter of LCA for compliance, and oversees LCA-based compliance under the RFS2.

ISO/ International Standards Organization.

SETAC/ Society of Environmental Toxicology and Chemistry, first produced guidelines. Along with the United Nations Environmental Program, supporting methods and guidance development.

IPP/ Integrated Product Policy concept initiated 2003.

EPDs/ Environmental Product Declarations (ISO 14025), based on the ISO standards, e.g.,

EISA/ US Energy Independence and Security Act, passed in 2007, authorized EPA for RFS2 and explicitly requires the use of LCA for biofuels and identifies indirect land use change.

RED/ EU Renewable Energy Directive, 2009. Sets down renewable energy requirements including bioenergy and biofuels, and explicitly requires LCAs for them, including reporting of direct and indirect land use change.

RTFO/ UK Renewable Transport Fuel Obligation. Uses a purpose-built LCA tool for biofuels GHG emissions.

RFS2/ Renewable Fuel Standard, overseen by the US EPA. California’s Low Carbon Fuel Standard, 2007. Requires reduced carbon intensity of transportation fuels of at least 10% compared to fossil analogs, based on LCA.

Policy requirement LCA issues

Clear Answers

LCA gives a way of thinking rather than providing an absolute answer. Results are often relative within the set of scenarios evaluated. Acknowledging uncertainty is important to scientists and practitioners.


There are gaps in knowledge and complexities in the data that are hard to translate into a single option. Results come with ranges and estimates of uncertainty. Single value answers are misleading, and comparison of possible ranges may be needed.


While not intrinsically complex, the aspects of an LCA are detailed and can become convoluted in practice. Databases are often proprietary. Data needs to be clear and transparent, and publically available.


LCA relies on being able to establish connections between causes and effects. To assign responsibility, answers are needed to questions like: Is the mechanism well understood? How well is causality known for the mechanism?

Risk Assessment

LCA does not reflect risk, just the result of a single particular project. Integration to other techniques beyond LCA is needed.


The interlinked global challenges of climate change, resource depletion, and population growth require avoiding unintended consequences. Combining this with the sometimes complex issues associated with bioenergy and its production mean that new – and crucial – questions are being asked of LCA to support policy decisions.



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