The Climate Registry, whose members include 39 States, D.C., three Canadian provinces, three Native American tribes, and one Mexican state, was created to voluntarily track greenhouse gases. For current members, see http://www.theclimateregistry.org/memberlist.html. The data can be used, for example, to create regional climate initiatives. Some cap-and-treat legislation has proposed giving extra credits to companies that join the Climate Registry before the law(s) are enacted. The Registry has now released a General Reporting Protocol, which sets forth policy guidelines, technical guidelines, and methods for quantifying emissions. Approximately 75 companies and other entities have agreed to be "founding reporters", including Pacific Gas & Electric Co., Shell Oil, Kennecott Utah Copper, Los Alamos National Laboratory, and Duke Energy Corp. For information on The Climate Registry, see http://www.theclimateregistry.org/. For information on the Reporting Protocol, see http://www.theclimateregistry.org/downloads/GRP.pdf. For a discussion of cap-and-trade vs. carbon tax approaches to addressing GHG emissions, see http://www.knowledgeproblem.com/archives/002068.html and http://www.carbontax.org/blog/cap-and-trade/.