Dr Bing Jones has been taking part in protests arranged by Insulate Britain, who targeted junctions 9 and 10 of Britain’s busiest motorway at 7.57am on Tuesday.
Footage taken at the scene by LBC showed the protesters walking on to the motorway and sitting down on the ground in front of moving traffic.
Speaking to BBC Radio 4’s PM programme, the Sheffield environmentalist – who protested on the M25 on Monday and has been arrested four times in the past eight days – said: “I accept that I put my life at risk. I don’t really accept that we have put other lives at risk.
“There are traffic jams continually, accidents happen daily, there are roadblocks for roadworks – all sorts of problems like that. The traffic increases and decreases in speed.
“I’m not worried about other people. I am a little bit worried about myself; my wife is very anxious about me.
“But I think it is worth it, I really think it is worth it. I’m willing to sacrifice, I’m willing to go to prison over this because people need to realise – people don’t see the maths.”
He added: “The disruption weighs heavy on me but it is necessary. Insulating houses is by far the most cost-effective means of reducing carbon emissions within the UK and it could bring millions of people out of fuel poverty.”
His quotes come as police warned the protestors that their tactics are likely to cause “serious injury or death”.
Surrey Police Chief Inspector Mike Hodder and Chief Superintendent Jerry Westerman told a press briefing that protesters charging into motorway traffic were putting drivers at a “very high” risk of death, but admitted police powers to charge the majority were “pretty limited”.
The pair spoke at a press briefing after the force arrested 38 activists from the group Insulate Britain
Chief Superintendent Westerman said the demonstrators were cleared by 8.17am and were being held at various custody centres, but none had been charged by 4pm.
Meanwhile, Downing Street backed police in taking “swift action” against the environmental protesters on the M25.
The forthcoming Police, Crime, Sentencing and Courts Bill will give officers “the tools they need to address this problem”.
A Number 10 spokesman said: “The police have our full support in taking swift action. That kind of disruption is dangerous and takes police away from communities where they are needed most.”
The Police, Crime, Sentencing and Courts Bill is controversial because of its measures aimed at curbing protests.
The new legislation “helps police better manage demonstrations so that legitimate groups can make their voices heard without disrupting the lives and livelihoods of others”, the spokesman said.