Can tariffs be used to enforce Paris climate commitments?

On June 14 the Trump administration announced new tariffs on $50 billion of Chinese goods, which prompted China to launch retaliatory measures in a trade war it claims the U.S. has started. A few days later, the U.S. president threatened to impose a 10 percent tariff on $200 billion of Chinese goods, sparking another warning from Beijing that it would hit back again. The administration had earlier imposed a 25 percent tariff on imports of steel, and a 10 percent tariff on aluminum, on all countries, leading several U.S. allies to devise their own plans for tariffs on U.S. goods. The European Union, for instance, just imposed penalties on $3.2 billion worth of American products. These developments may be just the beginning of an escalating trade war between the U.S. and the rest of the world.