The demonstrator refused to sit down and prevented the flight from taking off on time.
“Remove him from the plane,” one passenger can be heard saying, in video footage filmed on the aircraft.
Another shouts: “How long are you going to be?”
“I don’t wish to travel with you but I don’t wish to get off [the plane],” the man said, when asked what he was doing by a member of the cabin crew.
“I’m very sorry. I’m extremely sorry for the inconvenience.”
“Today there’s a protest at this airport,” he added.
Passengers can be heard shouting at the man to “sit down and...protest.”
“We have two generations of human civilisation left, if we carry down what we’re doing,” the climate change demonstrator said.
Nicholas Watt, the political editor of the BBC’s Newsnight programme, said he was on the plane.
“On runway and about to take off when smartly dressed man in late middle age stood up with iPhone to deliver lecture on climate change up and down aisle.”
“Cabin crew calmly and very politely asked protestor to resume his seat.
“Politely but persistently he declined and proceeded to deliver his lecture on climate change in aisle.
“Plane was at the end of runway. So the pilot taxied back to gate where plane was met by throng of police.
“They came on board and escorted the protestor off the plane. No skirmish and protestor left the plane”.
Andy Millward, who filmed footage of the protester said passengers had to leave the aircraft.
“We were disembarked but now being loaded back on,” he said.
Hundreds of climate change activists also attempted to shut down the airport on Thursday by blocking the main entrance for passengers.
Other glued themselves to the floor.
The group are hoping to stage a “Hong Kong-style occupation of the terminal building” to protest against the east London airport’s planned £2bn expansion.
“We can’t carry on with life, with business as usual,” an activist who gave her name as Clare, said.
Police officers have made several arrests at the site.
The airport demonstrations come on the fourth day of climate change protests, taking place across central London and other major cities around the world.
Additional reporting by agencies
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies