GP Chris Newman had never been to a protest until he joined Extinction Rebellion campaigners in October calling for the government to take drastic action on climate change.

Six months later he decided he was willing to be arrested for the cause when the eco group brought central London to a standstill for a fortnight through "non-violent civil disobedience".

Chris, from Manor House, was already living more of a "zero waste lifestyle", had reduced his plastic consumption and turned veggie a year ago - but to see XR protesters was the "straw that broke the camel's back".

"I saw lots of people who really care and compared myself to them, and thought: 'Wow, these people are actually prepared to put themselves on the line,'" he said. "Climate research indicates there will be unprecedented deaths from heat waves, severe weather and social unrest caused by mass 'climate immigration'.

"There will be water insecurity, malaria is coming north and Lyme disease is becoming more common. Some recognised scientists even put the risk of complete human extinction at 5pc in the next 80 years. Imagine every baby being born with a hole-in-the-heart but refusing to treat them - these are the levels of risks we are ignoring for the youngest generation."

But he was upset at the media's reaction to the protests.

"They were talking only about the disturbance and not about the underlying problem," he said. "It was easy for them to portray people as extreme lefties, but there are a lot of sensible, seriously smart people involved in the movement."

Chris has now set up a group for his profession - Doctors for XR - to use their standing in society to legitimise the movement. He is clear, though, that he does not back plans to shut down Heathrow Airport with drones next month.

"As imperfect as they are, XR are getting people talking and they got a government response," said Chris.

"Right now this type of group is vital for us all, though they may make mistakes from time to time. "Doctors don't have the answer, but we are deeply worried about the health consequences. We want to use the trust that is given to us to say: "Look this is a public health crisis. It will affect you and your children no doubt, so listen to the climate scientists, listen to the experts and listen to what they are saying is the solution."