The United States is helping lead the charge at UN climate talks to phase out fossil fuels, but the superpower's status as the world's top oil producer is already casting doubt on its credibility.
Often cast by environmentalists as a laggard or even villain in climate diplomacy, especially under Republican presidents, the United States has startled some veteran observers at the COP28 summit by supporting calls to end extraction of oil, gas and coal, with major oil exporter Saudi Arabia the most vocal opponent.
