An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

GLIMPSE – A computational framework for supporting state-level environmental and energy planning

What is GLIMPSE?

GLIMPSE is a decision support modeling tool being developed by EPA that will assist states with energy and environmental planning through the year 2050. Users of GLIMPSE can explore the impacts of energy technologies and policies on the environment.  For example, GLIMPSE can examine measures that promote energy efficiency, estimating the resulting energy savings, analyzing how emissions and air quality would be affected, and reporting how energy-related water use would change. Additional technologies that could be analyzed include electric and hydrogen fuel cell vehicles, wind and solar power, and carbon capture and sequestration.

An exciting feature is that users can specify energy, air quality, and water use goals within GLIMPSE, which then identifies cost-effective strategies for meeting those goals.  For example, states could use GLIMPSE to develop air quality management strategies that also meet renewable electricity targets, energy security objectives, and factor in how droughts could affect power plant operations.

GLIMPSE is a graphical user interface built on the Global Change Assessment Model (GCAM), developed by the Pacific Northwest National Laboratory (PNNL). The GCAM model simulates the interactions between human systems (such as economy, energy, agriculture, land use, and buildings) and earth systems (such as water and carbon cycles). PNNL and EPA researchers are working together to improve GCAM’s ability to support environmental analyses.

What are the benefits of GLIMPSE?

Energy system technologies, emissions from energy sources, and environmental and health impacts are all interrelated so a change in one area may impact another, either positively or negatively. GLIMPSE allows decision-makers to examine their policy options holistically to ensure they are maximizing the environmental and health benefits.

GLIMPSE has many strengths that include the following features:   

User-Friendly: Users can specify many complex technology or policy scenarios in minutes. GLIMPSE includes tools for visualizing model results, including the energy and environmental impacts of scenarios.

Fast: Once a scenario has been specified, model results are available within hours.

Flexible: Many of the assumptions about the future can be changed. For example, users could explore alternative assumptions about population and economic growth, technology availability, and future policies.

Comprehensive: By simulating the interactions among human and earth systems, GLIMPSE can identify important unintended consequences and other policy considerations that may not otherwise be apparent. 

Multi-scale: Users can specify policies or examine energy technologies at the state, regional, or national level within the context of a global scenario. 

Who should use GLIMPSE?

GLIMPSE software will be useful to federal, regional and state policy analysts, energy and environmental planners, and faculty and students performing environmental and energy research. 

How does GLIMPSE work?

GLIMPSE runs on Windows and requires no special software or hardware. Future versions of GLIMPSE will also execute on Linux and Apple computers.

How do I get GLIMPSE?

 GLIMPSE is still under development and not yet publicly available. It is being used in an academic setting by students at Duke University’s Nicholas School of the Environment and in partnership with the Pennsylvania Department of Environmental Protection and the Mid-Atlantic Regional Air Management Association (MARAMA) under a Regional Applied Research Effort (RARE) project with EPA’s Region 3.  It is anticipated that GLIMPSE will be publicly released in late 2020.

Technical Contacts:

  • Dan Loughlin,
  • Chris Nolte,

Related Publications/Presentations:

Ou, Yang, J. Jason West, Steven J. Smith, Christopher G. Nolte, and Daniel H. Loughlin. “Air pollution control strategies directly limiting future health damages in the US.” Nature Communications 11 (2020): 957, doi:10.1038/s41467-020-14783-2.

Ou, Yang, Steven J. Smith, J. Jason West, Christopher G. Nolte, and Daniel H. Loughlin. “State-level drivers of future fine particulate mortality in the United States.” Environmental Research Letters 14 (2019): 124071, doi:10.1088/1748-9326/ab59cb.

Ou, Yang, Wenjing Shi, Steven J. Smith, Catherine M. Ledna, J. Jason West, Christopher G. Nolte, and Daniel H. Loughlin. "Estimating environmental co-benefits of U.S. GHG reduction pathways using the GCAM-USA Integrated Assessment Model." Applied Energy 216 (2018): 482-493, doi:10.1016.j.apenergy.2018.02.122.

Shi, Wenjing, Yang Ou, Steven J. Smith, Catherine M. Ledna, Christopher G. Nolte, and Daniel H. Loughlin. "Projecting state-level air pollutant emissions using an integrated assessment model: GCAM-USA." Applied Energy 208 (2017): 511-521, doi:10.1016/j.apenergy.2017.09.122.

Fact Sheet:

View the GLIMPSE fact sheet here.