“Otherwise, there will be double counting, which is exactly what Brazil and many other countries have tried to prevent.” Esc reductions are likely to offset aviation emissions under the International Civil Aviation Authority`s (ICAO) Corsia programme, although they are not directly mentioned in the Paris text. (Corsia is the United Nations system for offsetting airline emissions.) Somewhat enigmatically, the draft regulations in Article 6.4 instead refer to “purposes other than contributions to NDCs”, using language that could cover Corsia or other future systems. A little-known and highly technical part of the Paris Agreement could “make or break” the regime – and its goal of avoiding dangerous climate change. To finalise the settlement, negotiators must navigate a thicket of impenetrable jargon, a series of technical accounting challenges and traps of “constructive ambiguity” in the text, often hiding incompatible visions of how Article 6 should work and what it was created for in the first place. The Madrid negotiations can build on the significant progress made at COP24 in Katowice, as well as the intensive diplomatic and technical efforts over the past year to bring us to a better place. Most importantly, countries must resist the urge to simply tick off the rules of Article 6 – they must do them right. Article 6 must support, not undermine, the ambition and environmental integrity of the Paris Agreement and countries` commitments under the Convention. The lack of agreement on how to solve this problem reflects the technical challenges it poses, rather than political disagreements over the appropriate solution, says former co-chair Kizzier. Although Article 6.7 states that the annual COP must adopt “rules, modalities and procedures” for the carbon market under Article 6.4, there are differences of opinion on the extent of national oversight of its functioning compared to the UN Oversight Body, which signs each individual draft or methodology. Avoid double counting: countries were clearly concerned about double counting at COP21 in Paris; the need to avoid them is mentioned no less than seven times in the Paris Agreement and its decision cop (decision 1/CP.21). .