In defense of the ULSD decision, and the EPA, here are a few more data points to consider...
Older Diesel engines produce soot. Some more than others. This translates into "Particulate Matter" or PM.
This just in:
PM2.5 levels in many areas of the Country are at an unhealthy level:
The biggest offenders are coal power plants and vehicle exhaust. Older diesels have a high output of PM comparable to gasoline engines -- which is why action was taken.
We're making ourselves sick. It seems like a sensible regulation to me. EPA bashing is the easy way out.
More info:
EPA Regulatory Actions for Nonattainment.
RH77