Guardian: A levy on all airline tickets and a global trading system for aircraft emissions are the contrasting proposals presented today to tackle the impact of flying on climate. Negotiators at UN climate talks in Bonn were told by the world’s poorest 49 countries that the annual 760m international air passengers should each pay a levy of about $6 (£5.4) on every flight to help those nations adapt to climate change. The least developed group of countries (LDCs) said a modest levy could …