on the Environmental Model Guidance Document
and on the
Environmental Model Knowledge Base
In January 2004, the U.S.
EPA released two products to improve EPA's use of environmental models
(Draft Guidance on the Development, Evaluation, and Application of Regulatory
Environmental Models and the Models Knowledge Base). The Agency frequently
relies on a wide range of models to support regulatory decisions. These
include models to simulate the fate of pollutants, to estimate pollution's
impacts on human health and the environment, and to evaluate the costs
and benefits of alternative policies for environmental protection. In
the past, parties impacted by EPA's policies have sometimes questioned
the credibility of these models.
These two complementary products work in tandem to describe and document
good modeling practices. The guidance recommends best practices to help
determine when a model, despite its uncertainties, can be appropriately
used to inform a decision. The Knowledge Base is, a web-accessible database
of information on some of EPA's most frequently used models, is intended
to be a living demonstration of the recommendations from the Guidance
for Environmental Models. The former recommends what information about
models to document, while the latter serves as a repository where this
information is documented. Currently, the Models Knowledge Base contains
about 100 models. Both products are available from EPA's Council for Regulatory
Environmental Modeling (CREM) Internet site at www.epa.gov/crem.
By providing access to our tools and methods, the EPA increases transparency
and can improve the public's understanding of how sound science is used
to make environmental decisions. In short, these products help to foster
a culture of building the black box, as models are sometimes referred
to, out of plexiglass.