London, Dec 17 (IANS): A global fleet of composite planes could reduce carbon emissions by up to 15 percent but lighter planes alone will not enable the aviation industry to meet its emissions targets, says research.

Emissions during the manufacturing of composite planes are more than double in comparison to aluminium planes.

But since the lighter aircrafts use significantly less fuel, these increased emissions are offset after just a few international flights.

Over its lifetime, a composite plane creates up to 20 percent fewer CO2 emissions than its aluminium equivalent.

The study by the Universities of Sheffield, Cambridge and UCL (University College London) is the first to carry out a comprehensive life cycle assessment (LCA) of composite planes like Boeing Dreamliner 787 or Airbus 350 and extrapolate the results to the global fleet.

"It shows that the fuel consumption savings with composites far outweigh the increased environmental impact from their manufacture. The environmental and financial savings from composite planes mean that these materials offer a much better solution," said Alma Hodzic, professor in advanced materials technologies at University of Sheffield.

"Given that global air traffic is projected to increase four-fold between now and 2050, changing the materials used could avoid 500 million tonnes of CO2 emissions in 2050 alone, a value that roughly corresponds to current emission levels," explained Lynette Dray from University of Cambridge.

The industry target is to halve CO2 emissions for all aircraft by 2020 and while composites will contribute to this, it cannot be achieved by the introduction of lighter composite planes alone.

"However, our findings show that composites - alongside other technology and efficiency measures - should be a part of the picture," Hodzic concluded.

The study was published in the International Journal of Life Cycle Assessment.