The substitute amendment offered by Rep. Barbara Boxer (D-Calif.) to S. 3036 would have created a cap-and-trade system for reducing carbon dioxide and other greenhouse gases. The system would have forced utilities, factories, etc., to collectively reduce their greenhouse-gas emissions by 71 percent by 2050, though individual companies could emit more by purchasing allowances from companies that emit less. The cost to the economy would be in the trillions.

Mandates on greenhouse-gas emissions are not constitutionally authorized and would harm the economy.