Washington and Oregon lawmakers want to end their legislative sessions; however, accounting for the costs of carbon emissions is a major road block.

In Salem, rural Republican senators are boycottingsession and thereby denying majority Democrats a quorum to vote on a “cap and trade” bill. The measure calls for an 80 percent state reduction in greenhouse gases (GHG) by 2050. The system would be similar to existing programs in California and some Canadian provinces.

The state would set a cap on total GHG emissions. Oregon’s largest 100 industries are targeted. They would be required t...