The shocking film was commissioned by the British campaign group Plane Stupid, which describes itself as a network of grassroots groups that take non violent direct action against aviation expansion.

The film, which will also be shown in UK cinemas, shows the bloodied bears falling from the sky, bouncing off buildings and violently landing on footpaths and cars.

"An average European flight produces over 400 kg of greenhouse gases for every passenger... That's the weight of an adult polar bear," the clip states.

Warning: This video is graphic and should only be viewed by mature audiences

On its website, Plane Stupid writes: "We have a problem. We're flying too much, and it's changing the earth's climate. Aviation is the fastest growing cause of climate change. But instead of doing anything about it, the Government is planning more flights and larger airports.

"Like you, we're worried about climate change. Like you, we don't think the Government can be trusted to do what needs to be done."

However some commentators have questioned the group's shock tactics and whether it will change travellers' behaviour.