Norwegian is partnering with Oslo-based technology company Chooose to give passengers the option of purchasing a carbon offsetting plan for their flights.

When customers book a flight, they’re informed about how Norwegian’s flight emissions compare to the industry average. Then, the system makes a CO2 emissions calculation “based on the official methodology of the United Nations’ International Civil Aviation Organization, the International Council of Clean Transportation and Norwegian’s own flight emissions data.”

Passengers then have the option of offsetting their carbon footprint at check-out. The airline said the offsetting “is then performed through carefully selected CO2-reducing clean energy projects in regions Norwegian flies to.”

The projects in the plan are certified by the UN and the Gold Standard and include supporting coastal wind energy in Vietnam, converting landfill gas to energy in Thailand, and run-of-river hydro energy in rural Laos.

The airline is the first to sign the United Nations Framework Convention on Climate Change pledge, which commits Norwegian to becoming climate neutral by 2050.

“Norwegian has been named one of the world’s most environmentally friendly airlines and we are continuously working to reduce our emissions through new initiatives. We’re now putting a price on actual carbon emissions from flying, making it easy for all our customers to take climate action,” said Geir Karlsen, acting CEO, Norwegian.

“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.”