WASHINGTON — Efforts to mitigate climate change are prompting countries across the world to embrace dramatically different policies toward industry and trade, bringing governments into conflict.These new clashes over climate policy are straining international alliances and the global trading system, hinting at a future in which policies aimed at staving off environmental catastrophe could also result in more frequent cross-border trade wars.In recent months, the United States and Europe have proposed or introduced subsidies, tariffs and other policies aimed at speeding the green energy transition. Proponents of the measures say governments must move aggressively to expand sources of cleaner energy and penalize the biggest emitters of planet-warming gases if they hope to avert a global climate disaster.But critics say these policies often put foreign countries and companies at a disadvantage, as governments subsidize their own industries or charge new tariffs on foreign products. The policies depart from a decades-long status quo in trade, in which the United States and Europe often joined forces through the World Trade Organization to try to knock down trade barriers and encourage countries to treat one another’s products more equally to bo …
