U.S. airlines could get a pass from the European Union’s law capping greenhouse gas emissions from aircraft under a bill (S. 1956) the Senate passed unanimously on Sept. 22. The measure would authorize the Transportation Department to prohibit U.S. airlines from participating in the EU’s cap-and-trade system for greenhouse gas emissions. That system applies to all flights originating or landing in EU countries. U.S. airlines oppose the EU law and sought help from Congress. Last year, the House of Representatives passed a measure (H.R. 2594) similar to S. 1956. The House and Senate could work out their differences on the bills when they return to Washington, D.C., for a lame-duck session after the November election. The Senate’s move will increase pressure on the International Civil Aviation Organization, a United Nations agency that regulates international air travel, to finish a global deal to limit emissions from aircraft fuels, says Annie Petsonk, international counsel for the Environmental Defense Fund, an activist group.