Acting chief executive Geir Karlsen said with emission-free flying still some years away, offsetting was an “important tool” when it came to managing the current impact of aviation emissions.

The carrier has also become the first airline to sign a United Nations Framework Convention on Climate Change pledge to commit to becoming climate neutral by 2050.

“We’re now putting a price on actual carbon emissions from flying, making it easy for all our customers to take climate action,” said Karlsen. “Even if commercial aviation technology continues to develop and Norwegian keeps reducing its environmental impact, emission-free flying is not possible today.

“Carbon offsetting is an important tool in managing today’s emissions, and we know that many of our customers would like to compensate for emissions associated with their journey.”

It follows easyJet’s pledge last month to offset the emissions from fuel used on flights across its entire network.

When booking their travel, Norwegian customers will be informed of the emissions impact of their chosen flight, based on UN International Civil Aviation Organisation methodology. They will then offered the option to offset this during the checkout process.

Norwegian says the proceeds will fund “carefully selected” CO2-reducing clean energy projects in destinations it serves, all of which have certified by the UN and Gold Standard, the organisation founded in 2003 by the WWF – World Wildlife Fund – in collaboration with various NGOs to certify the “environmental integrity” of individual projects.

Oslo-based CHOOOSE’s platform, meanwhile, integrates into the flight checkout process. “CHOOOSE collaborates with those who challenge the status quo, demonstrate they’re committed to reducing emissions, and take responsibility for the elephant in the room – some carbon footprints cannot be entirely avoided based on today’s technology,” said chief executive Andreas Slettvoll.

Norwegian claims that since 2008, it has reduced its emissions by 30% per passenger kilometre through investment in newer, more fuel-efficient aircraft.