WHICH COUNTRIES should spend more to save the planet? That is a question that diplomats and activists are sparring over at COP29, the UN’s climate summit in Azerbaijan from November 11th to 22nd. A common answer is China, which Westerners accuse of contributing too little to efforts aimed at helping poor countries cope with climate change. For nearly two decades China, the world’s second-largest economy, has been the biggest emitter of carbon dioxide.