The United States has taken a sudden, wild lurch into the emerging global movement toward imposing tariffs on emissions-intensive goods from countries with weak environmental policies. …The new legislative proposal from U.S. Democrats would apply to a wider range of imports… and absent a national carbon-pricing system, to which border adjustments can most easily and transparently be linked, it would involve much greater political discretion around which imports are penalized. As with the EU plan, it has the worthy premise… but the hastily assembled American effort, points to concerns about how the tariffs could be wielded as protectionist cudgels. For Canada, suddenly at risk of getting caught in the middle of trade wars in ways that could hurt industrial and emissions-reduction interests, it should prompt both urgent diplomatic efforts in Washington and a reckoning with how quickly to ready carbon tariffs of our own. (to access the full story, a Globe & Mail subscription may be required).