One area where states have developed expertise is in the registration and tracking of greenhouse gas (“GHG”) emissions. Even though tracking GHG emissions has recently become a mainstream federal issue, Wisconsin has long been a leader in this area. Since 1993, Wisconsin has required any facility that emits more than 100,000 tons of carbon dioxide (“CO2”) to report its emission levels to the state Department of Natural Resources. It is the only state with such a requirement. Additionally, dozens of sources that fall well below the threshold voluntarily report their emissions, providing the state with a detailed, multi-year profile of its major CO2 sources. The profile includes most major electric utilities in the state, a wide range of large industries, and a mixture of smaller sources.
Rohleder, Jennifer M. “Translating State Experience into Federal Climate Policy.” Sustainable Development Law & Policy, Fall 2007, 12, 78.