A metric to define a CO2 standard for new aircraft has been hailed as a “milestone” by Iata.

The International Civil Aviation Organisation’s environment committee agreed on the common metric for measuring the emissions of new aircraft.

It paves the way for ICAO to formally adopt a standard for CO2 which the airline body says will drive “continuous improvement” in fuel efficiency.

The standard is expected to be fully developed by the end of 2013. This is one aspect of a comprehensive approach to managing the 2% of global manmade carbon emissions attributable to aviation, according to Iata.

The organisation’s director general and chief executive Tony Tyler said: “This major milestone in developing a CO2 standard for new aircraft demonstrates the commitment of the global community to environmental sustainability and ICAO’s ability to lead progress.

“Establishing a standard for future generations of aircraft will help to ensure that the environmental benefits of the billions of dollars of airline investments in new aircraft are being maximized.”

But he warned: “Unfortunately, the insistence by the European Commission’s Directorate-General for Climate Action on the unilateral and extra-territorial inclusion of international aviation in its emissions trading scheme is putting the success of this process at risk.

“It is a divisive scheme, forced through at a time when the global community needs to unite and deliver a global solution.”

Airlines, airports, manufacturers and air navigation service providers agreed a strategy three years ago to achieve a 1.5% fuel efficiency improvement per year to 2020, carbon-neutral growth from 2020, and a 50% cut in net emissions by 2050 over 2005 levels.