"U.N. agency seeks to end rift on new aircraft emission rules", 7 Feb 2016

…Proposals being debated in Montreal by the International Civil Aviation Organization (ICAO), the United Nations' aviation agency…to come up with the world's first carbon dioxide emissions standards for aircraft as part of the industry's contribution to efforts to combat climate change…Differences remain on where to place the bar on efficiency…The proposals could revive pressure on…Airbus to upgrade the world's largest passenger jet…with new engines…It could also spell the end for Boeing's…747-8 passenger jet and freighter…Airbus and Boeing declined to comment on negotiations…A less stringent standard would apply to aircraft already in production, but…some of these planes would need to have costly improvements…Participants have been weighing 10 different options for new targets, with one being the weakest and 10 requiring the greatest reduction in emissions…Tougher standards have higher cost implications for planemakers…Environmental groups said the standard will boost efficiency, but…the standard needs to be accompanied by a strong global market-based approach.