Word is that the White House has given the go ahead for the Environmental Protection Agency to make a formal finding that the emission of greenhouse gases may be reasonably anticipated to harm public health and welfare, perhaps as early as tomorrow. This finding is the trigger for the regulation of greenhouse gases under the Clean Air Act. So, if such a finding is made — and presumably finalized after a notice-and-comment rulemaking — the next step will be for the EPA to begin developing regulations to control GHG emissions from motor vehicles and other sources.