Aviation currently accounts for around 2.5% of global carbon emissions and with the industry has pledged to halve its 2005-level footprint by 2050 through an offsetting program. Therefore engineering firms were keen to showcase a range of eco-friendly inventions such as hybrid engines, urban mobility vehicles, and autonomous flight systems at the annual event, the largest for the aerospace industry.

"The Paris Air Show is an exhibition essentially oriented towards the future, which it helps to shape. This is why innovation is one of the main themes of this 53rd edition," said the Paris organizers.

It's not just environmental considerations driving the research: UBS estimates sales of hybrid engines will be worth $178 billion by 2040, while the electric vertical take-off and landing (eVTOL) market will be a $285 billion business by 2030.