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ECONOMIC INPUT-OUTPUT LIFE CYCLE ASSESSMENT | EIO-LCA: Free, Fast, Easy Life Cycle Assessment
The Economic Input-Output Life Cycle Assessment (EIO-LCA) method estimates the materials and energy resources required for, and the environmental emissions resulting from, activities in our economy. The EIO-LCA method was theorized and developed by economist Wassily Leontief in the 1970s based on his earlier input-output work from the 1930s for which he received the Nobel Prize in Economics. Researchers at the Green Design Institute of Carnegie Mellon University operationalized Leontief's method in the mid-1990s, once sufficient computing power was widely available to perform the large-scale matrix manipulations required in real-time. This website takes the EIO-LCA method and transforms it into a user-friendly on-line tool to quickly and easily evaluate a commodity or service, as well as its supply chain. The results from the EIO-LCA model and this website are free for non-commercial use and may not be used in other derivative works or websites without permission.
Results from using the EIO-LCA on-line tool provide guidance on the relative impacts of different types of products, materials, services, or industries with respect to resource use and emissions throughout the supply chain. Thus, the effect of producing an automobile would include not only the impacts at the final assembly facility, but also the impact from mining metal ores, making electronic parts, forming windows, etc. that are needed for parts to build the car.
The EIO-LCA models available on the site apply the EIO-LCA method to various national and state economies. Each model is comprised of national economic input-output models and publicly available resource use and emissions data. Since its inception in 1995, the method has been applied to economic models of the United States for several different years, as well as Canada, Germany, Spain, and select US states. The on-line tool has been accessed over 1 million times by researchers, LCA practitioners, business users, students, and others.
Life cycle assessment, using the EIO-LCA method and on-line tool, as well as other LCA methods, is a major research focus for the Green Design Institute at Carnegie Mellon University. Over the past 15 years, our group has investigated numerous products, services, and infrastructure systems using LCA as a fundamental component of analysis, becoming a leading research group in the field. GDI researchers and students have produced numerous LCA studies using a wide range of LCA techniques resulting in over 100 publications on the topic.
We have made tutorial screencasts of how to use EIO-LCA on the web.
Matlab versions of the 1997 and 2002 US detailed models are posted to the EIO-LCA forum.
Data on hazardous waste, water use and IMPACT2002 summary assessment data (for toxics only) have been added to the US 2002 model.
Data on detailed toxic releases will be posted in summer 2012.
The EIO-LCA model as available on this website is for non-commercial use.
Commercial use and non-commercial use licenses are available which include direct access to the underlying data and other advanced tools.
licenses
About The EIO-LCA Method
The Economic Input-Output Life Cycle Assessment (EIO-LCA) method estimates the materials and energy resources required for, and the environmental emissions resulting from, activities in our economy. It is one technique for performing a life cycle assessment, an evaluation of the environmental impacts of a product or process over its entire life cycle. The method uses information about industry transactions - purchases of materials by one industry from other industries, and the information about direct environmental emissions of industries, to estimate the total emissions throughout the supply chain.
This section of the website provides an overview of life cycle assessment (LCA), different approaches to LCA, the theory and mathematical method of the EIO-LCA approach, assumptions and uncertainty in the model, and limitations to the approach. The information is only a brief overview, however, and is not intended to encompass all issues and nuances of the topics. References are provided to resources with more detailed information and analyses.
- A primer on life cycle assessment
- Approaches to life cycle assessment - process-based and input-output based
- EIO-LCA theory and method
- Assumptions, uncertainty and other considerations when using the EIO-LCA method
- Limitations of EIO-LCA
- Interpretation of results
- References to articles and books regarding the development of the EIO-LCA method and eiolca.net on-line tool
Economic Input-Output Life Cycle Assessment (EIO-LCA) is a method - a mathematically defined procedure using economic and environmental data to determine the effect of changing the output of a single sector. The method can be applied to any economy defined by the transactions between sectors. Each application of the method defines an EIO-LCA model. Go to the Models page for more information about the various models available on eiolca.net.
Also note that we published a 'handbook' with RFF Press in 2006 to help explain the EIO-LCA method and to show how to use it with examples:
Hendrickson, C. T., Lave, L. B., and Matthews, H. S. Environmental Life Cycle Assessment of Goods and Services: An Input-Output Approach, Resources for the Future Press.
You can order it from RFF with this PDF invoice or buy the hardback or paperback edition from Amazon.com.
Economic Input-Output Life Cycle Assessment | Green Design Institute | 5000 Forbes Avenue Pittsburgh, PA 15213 | (412) 268-2299
Green Design Institute | Carnegie Mellon Home
Economic Input-Output Life Cycle Assessment | Green Design Institute | 5000 Forbes Avenue Pittsburgh, PA 15213 | (412) 268-2299
Green Design Institute | Carnegie Mellon Home
Limitations of the EIO-LCA Method and Models
The factors that make the EIO-LCA method an efficient and robust tool also limit its use for life cycle assessment.
First, the results of an EIO-LCA analysis represent the impacts from a change in demand for an industry sector. Depending on the model chosen, an industry sector represents a collection of several industry types, and this aggregation leads to uncertainty in how well a specific industry is modeled. For example, in the U.S. models, one sector represents Power Generation and Supply, which would include coal-fired plants with high levels of CO2 and particulate emissions as well as hydropower plants with virtually no CO2 or particulate emissions. The results for impacts from the Power Generation and Supply sector thus represent the 'average' impacts for generating electricity. Similarly, a sector such as the Electronic Computer Manufacturing sector produces hand-held computers (PDAs), laptops, desktops, workstations, and mainframe computers. Since making these products requires similar processes, they are grouped together in a single sector. So, the method is limited in its ability to model the effects of 'producing one laptop' but is good at modeling the effects of the Electronic Computer Manufacturing sector as a whole. (We like to point out that the U.S. models designate one sector entirely for Tortilla Manufacturing, so the impacts for making tortillas are well-represented.) Non-U.S. models are more aggregated, with up to only 100 sectors representing all industries. See the model information for the number of sectors represented in the economy of a given model.
Second, as an LCA tool, the EIO-LCA models are incomplete in as much as a limited number of environmental effects are included. The EIO-LCA models use as the basis for data only that which is publicly available. While industry specific data is publicly available for a number of environmental effects, we do not have data for impacts such as habitat destruction, non-hazardous solids wastes, or non-toxic pollutants to water. Some data used in earlier models (e.g., fertilizers) are no longer collected at the national level due to efforts to minimize reporting burden of companies. Other sources and LCA methods will need to be consulted to account for a full range of environmental impacts.
Third, the EIO-LCA method, models, and results represent the inventory stage of the LCA. The results estimate the environmental emissions or resource consumption associated with the life cycle of an industry sector, but do not estimate the actual environmental or human health impacts that these emissions or consumption patterns cause. For example, the U.S. models estimate the emissions of particulates to the air, but do not estimate the increased number of hospitalizations or deaths due to these emissions. Again, other sources and LCA methods will need to be consulted to account for translating the inventory results from an EIO-LCA analysis into impact on the environment.
Comparison of EIO-LCA with Process-Based Models
(from Hendrickson, C. T., Lave, L. B., Matthews, H. S. (2006). Environmental Life Cycle Assessment of Goods and Services: An Input-Output Approach. Resources for the Future Press.)
Process-Based LCA EIO-LCA
Advantages
results are detailed, process specific
results are economy-wide, comprehensive assessments
allows for specific product comparisons
allows for systems-level comparisons
identifies areas for process improvements, weak point analysis
uses publicly available, reproducible results
provides for future product development assessments
provides for future product development assessments
provides information on every commodity in the economy
Disadvantages
setting system boundary is subjective
product assessments contain aggregate data
tend to be time intensive and costly
process assessments difficult
difficult to apply to new process design must link monetary values with physical units
use proprietary data imports treated as products created within economic boundaries
cannot be replicated if confidential data are used
availability of data for complete environmental effects
uncertainty in data
difficult to apply to an open economy (with substantial non-comparable imports)
uncertainty in data
Economic Input-Output Life Cycle Assessment | Green Design Institute | 5000 Forbes Avenue Pittsburgh, PA 15213 | (412) 268-2299
Green Design Institute | Carnegie Mellon Home
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