BELÉM, Brazil — The European Union is under pressure to defend its new carbon tariff scheme as trade tensions swamp this year’s global climate talks. Long-simmering diplomatic frictions over the upcoming levy are reaching boiling point in the tropical heat of Belém, with some developing countries pushing for the COP30 conference to effectively condemn the bloc’s green trade measures as protectionist. Trade has taken center stage at this summit, alongside traditional sticking points such as