environmental modeling

Evaluating Technologies for Greenhouse Gas Mitigation

To celebrate Earth Day and the Agency’s effort to expand the conversation on climate change, we are highlighting EPA climate change research with Science Matters articles this week.

Breaking Through? Evaluating Technologies for Greenhouse Gas Mitigation
EPA modelers develop innovative methods to assess low-carbon technologies.

Much of the energy we use to power our homes, cars, and industries is also the main source of greenhouse gases (GHG) responsible for global climate change. It follows then, that limiting emissions from the combustion of these energy sources could contribute toward a stable, sustainable environmental future.

Developing new “game changing” technologies and energy sources will be important to mitigate GHG emissions cost-effectively. But how can today’s decision makers identify technologies with true transformational potential for reducing global climate change over the long term?

EPA scientists and engineers are helping answer just that question. They are using sophisticated computer models to support decision makers by comparing potential mitigation technologies in terms of cost, environmental performance, economic impact, and more.

In one such effort, the results of which were recently presented in the journal Clean Technologies and Environmental Policy, EPA physical scientist Dan Loughlin and his research colleagues used an innovative modeling approach tapping the MARKet ALlocation (MARKAL) model to demonstrate a “breakthrough analysis” that researchers can use to identify technologies that can make a true difference in reducing GHG emissions.

MARKAL was created in the late 1970s by Brookhaven National Laboratory scientists to help partner researchers and others wade through the complex and far reaching differences and tradeoffs involved in making decisions and policies related to energy use. Over the next several decades, the model was improved and reworked to support new functionality, and to take advantage of increasing computational power. It is now one of several models that EPA’s own climate change researchers use.

“Breakthrough” in this case refers to a technology that can limit GHG emissions significantly and cost-effectively over the long haul, explains Loughlin. “We developed a methodology to examine the breakthrough potential of energy-related technologies, taking into account the complexities of the entire energy system.”

The researchers focused on MARKAL because of its comprehensive coverage of the energy system, from the importation, production, or manufacture of a particular energy source, right through its distribution and end use by a whole variety of interacting sectors.

“For example, using MARKAL we might ask ‘What would happen if the cost of solar photovoltaic technology goes down to 20 cents per kilowatt hour? Would it penetrate the market and yield significant reductions in GHG? Using MARKAL this way allows us to incorporate important multi-sectoral interactions in our analysis that would not be possible with less powerful tools,” says EPA engineer William Yelverton, who contributed to the breakthrough technology approach.

To demonstrate how such an approach could be used to support greenhouse gas mitigation decisions, Loughlin, Yelverton, and their EPA colleague Rebecca Dodder focused on a breakthrough analysis of utility-scale solar photovoltaics (PV). Their calculations suggest, for instance, that an 80% drop in the price of photovoltaics would lower the cost of cutting carbon dioxide emissions in the United States in half by $270 billion—potentially making it a technology breakthrough.

The research team plans to use this approach to evaluate and compare the breakthrough potential of additional energy technologies. In their paper, they and their coauthors write:


Fortunately, as a society, we have shown a great ability to innovate. Technology breakthroughs have led to putting humans on the moon and to downsizing electronics so that the smart phones in our pockets are more powerful than the supercomputers of several decades ago. Similar breakthroughs in low- and zero-carbon energy technologies will be needed to meet GHG mitigation goals identified as being necessary by the IPCC [Intergovernmental Panel on Climate Change]. This need raises important questions, such as ‘What constitutes a breakthrough?’ and ‘Where would breakthroughs be achieved most readily and most cost effectively?

Together, EPA researchers Loughlin, Yelverton, Dodder and their partners are working to answer those questions, and help provide the science and tools needed to address global climate change.

Learn More

EPA Climate Change Research

EPA Climate Change Methods, Models, Tools, and Databases

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action.

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Science Wednesday: Modeling Matters: Transparency in Action

Each week we write about the science behind environmental protection.Previous Science Wednesdays.

By Gabriel Olchin

In the age of transparent government, I think it helps to highlight specific products that make our research and approaches more apparent to the public. Transparency is important to me because I work in the field of environmental modeling, and models are often referred to as the ‘black-boxes’ of the research process; and a black-box is not transparent at all!

What does transparency mean, and why is it important to environmental modeling at the EPA?

The modeling research at the EPA is a complex science – one that we don’t take lightly. To me, transparency means providing the relevant information and documentation so that our stakeholders can understand how these ‘black boxes’ (models) work.

Models are used by the EPA for a variety of reasons: for regulatory rulemaking, as research tools, and to generate data that inform decisions. Each model used by the EPA is designed and developed with specific purposes in mind.

The EPA established the Council for Regulatory Environmental Modeling in 2000 to improve the quality, consistency and transparency of the models for environmental decision making. In short, the CREM helps to make the EPA’s modeling transparent. We maintain the Models Knowledge Base, an inventory of the computational models that are developed, used, and/or supported by EPA’s offices. For each model, the Models Knowledge Base provides information or documentation on:

  • the model’s development;
  • the model’s conceptual basis, scientific detail, and evaluation;
  • technical requirements and how to use the model;
  • information on the model’s inputs and outputs; and
  • directions for acquiring the model and links to further information.

The CREM’s latest effort has been focused on developing a suite of training modules for environmental modeling. These modules are designed to take our technical guidance document on environmental modeling and make it transparent to a broader audience. We also developed training modules on the legal aspects of environmental modeling, integrated modeling, and technical topics of model evaluation.

I’m often humbled working at an Agency with such talented modelers. I really enjoy my role at EPA helping to make the great modeling work done in our program and regional offices more transparent to our stakeholders.

About the author: Gabriel Olchin, a biological scientist, has been in the Office of the Science Advisor with the Council for Regulatory Environmental Modeling since 2009.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.