The current approach is inefficient and ineffective, imposing unnecessarily high costs due  (1) stranded capital investments from the installation of controls that later become obsolete when additional requirements are promulgated; (2) reduced lead time for complying with those requirements; (3) limited or non-existent flexibility for emissions trading to allow cost-efficient control options; and (4) a reliance upon lengthy, expensive, and uncertain litigation to sort out regulatory ambiguity and compliance with the law.
The high costs are because of the installation of controls and reduced lead time for compliance.