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Air and Climate Change Research

Models & Databases

Combustion & Emissions Control


Our objective in developing models and databases related to air pollutant emissions and climate change mitigation is to better understand the behavior of large and complex systems that cannot easily be studied experimentally.  This understanding can be of substantial value to industries, environmental agencies, and the technical community in general.  In addition, the development and distribution of models can enable others to evaluate specific situations that they face and help them to better understand those situations so that they can develop the most effective solutions to their specific environmental problems.


There is no single technical approach to developing useful models and databases, but to develop effective tools that generate information that is of use to others relies on a foundation of strong technical understanding of the system being modeled.  In all the modeling work we do, we begin by gaining an understanding of the state of the technologies that are included in the system being studied as well as the connections that exist within that system and with other systems.  For example, our work to model the U.S. energy system requires that we have a good understanding of the wide range of technologies used to produce and use energy, from coal mines to power plants to different types of residential heating and cooling systems, from oil production to refining to the range of different vehicle types.  In this example, we must also have an understanding of how the agricultural system operates, which will help us to incorporate biofuels into the energy system more accurately.  In all our models and databases, we begin by applying our expertise and our interactions with experts in government, industrial, and academic organizations to develop as much up-to-date information and understanding as possible.

Models Being Used and Developed

NRMRL is working on a range of models and databases related to air pollutant emissions control and greenhouse gas mitigation.  These include:

  • ISIS (Industrial Sector Integrated Solutions) Model for evaluating pollution reduction strategies for industries.
  • LandGEM (Landfill Gas Emissions) Model for estimating emission rates of landfill gas.
    LandGEM is an automated estimation tool with a Microsoft Excel interface that can be used to estimate emission rates for total landfill gas, methane, carbon dioxide, nonmethane organic compounds, and individual air pollutants from municipal solid waste landfills. 
  • Database for the MARKAL (MARKet ALlocation) Model of the U.S. energy system.
    NRMRL is developing technology and emissions databases for the entire U.S. and for nine regions of the U.S. for use in the economic-optimization MARKAL model.  The databases include the scope and structure of the energy system to be modeled, including resource supplies, energy conversion technologies, end use demand, and the technologies used to satisfy these demands. NRMRL’s database also includes emissions of sulfur dioxide (SO2), nitrogen oxides (NOx), and carbon dioxide (CO2). 
  • MSW-DST (Municipal Solid Waste Decision Support Tool) for evaluating the life-cycle environmental tradeoffs and full costs of solid waste management.
    The MSW-DST calculates life-cycle environmental burdens for all waste management activities including collection, transportation, material recovery facilities, transfer stations, composting, remanufacturing (of recovered materials), land filling, and combustion, as well as off-sets for the potential benefits from conservation of energy and materials.

Anticipated / Generated Impact and Products

The impacts of the models vary depending upon the purpose for which they were developed.  The CUECost and ISIS models have been used in regulatory development to assist in understanding the costs and pollution reductions of the regulations.  More generally, these models provide information about how complex systems respond to changes in technology and policies, and help understand the emissions reductions and the costs of those changes.

Better understanding of how these systems respond to possible changes in policy and technologies can lead to the development of more robust emissions reduction strategies at the local, state, regional, and national levels.  Such improvements can minimize the need for later revision of strategies and improve the total benefits associated with the application of environmental protection approaches.


The U.S. Cement idustry model will be released in the fall of 2010. At that time, references for the model and related documentation will be provided.



LandGEM - Landfill Gas Emissions Model, Version 3.02 (XLS) (MSN Excel 97-2003, 2.58 Mb)


US EPA. (2005 ). Landfill Gas Emissions Model (LandGEM) Version 3.02 User’s Guide. (PDF) (56 pp, 1.4 Mb)Publication No. 600/R-05/047.


S.A. Thorneloe, M. Laur, A. Reisdorph, C. E. Burklin, R. Pelt, and R. Bass. (1999). U.S. Environmental Protection Agency’s Landfill Gas Emission Model (LandGEM). Presented at 7th International Waste Management and Landfill Symposium, Cagliari, Italy, October 4-8.



US EPA. (2006). Shay, C. L., S. Yeh, J. Decarolis, D. H. Loughlin, C. L. Gage, AND E. Wright. EPA U.S. National MARKAL Database: Database Documentation. Publication No. EPA/600/R-06/057.




Status / Results

Coal Utility Environmental Cost (CUECost) Model Version 1.0: Contact William Yelverton (:yelverton.william@epa.gov).

ISIS framework currently includes a representation of the U.S. cement sector. This representation is being used to help inform the U.S. Portland Cement Industry related rulemakings. Further, the ISIS framework is now being expanded to include representations of the U.S. pulp & paper and iron & steel sectors. Also, the plans are to use the model to support other sector-based rulemakings and help inform climate legislation related discussions.

LandGEM was updated most recently in 2005.  No work is currently underway on the model.  Contact Susan Thorneloe (thorneloe.susan@epa.gov).

MARKAL databases are undergoing significant revisions and updates.  Current work is focused on updating the database to be consistent with the 2010 edition of the Annual Energy Outlook report published by the U.S. Department of Energy, Energy Information Administration.  Contact Carol Lenox (lenox.carol@epa.gov).  Additional projects include:

  • Improvements to the agricultural sector database (including biofuel feedstocks).  Contact Rebecca Dodder (dodder.rebecca@epa.gov)
  • Improvements to representation of the industrial sector in MARKAL.  Contact Ozge Kaplan (kaplan.ozge@epa.gov)
  • Incorporating non-CO2 greenhouse gas and mercury emissions into the MARKAL databases.  Contact Dan Loughlin (loughlin.dan@epa.gov)
  • Improvements to the electric sector representation in MARKAL.  Contact Will Yelverton (yelverton.will@epa.gov)
  • Evaluation of possible biofuel technology pathways.  Contact Tim Johnson (johnson.tim@epa.gov)
  • Assisting the development of state-specific energy systems using the MARKAL framework.  Contact Cynthia Gage (gage.cynthia@epa.gov)

MSW-DST is being updated to make it web-accessible.  Additional work is beginning to extend the MSW-DST to enable the evaluation of “tipping points” – points at which different waste management strategies begin to show positive benefits related to energy, material conservation, and greenhouse gas emissions.  Contact Susan Thorneloe (thorneloe.susan@epa.gov).


John Masters, Communications
Phone: 919-541-0634
Email: masters.john@epa.gov
U.S. EPA National Risk Management Research Laboratory
Air Pollution Prevention and Control Division
Mail Code: E343-02
Research Triangle Park, NC 27711

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