Insulate Britain held sit-in demonstrations at several locations across the southeast on Monday including Hertfordshire, Surrey, Kent and Essex.
About 20 protesters were filmed sitting in the middle of the road at junction 20 in Kings Langley, Hertfordshire, blocking access to the roundabout from both sides.
There were also reports of demonstrations at junction 3 in Swanley, junction 6 in Godstone, junction 14 at Heathrow, junction 30 at Thurrock and junction 31 at Lakeside/Purfleet.
Video footage posted on Twitter showed protesters with banners blocking off all four lanes of the motorway, as well as the slip road, during one incident.
Insulate Britain !
It's worth it ? M25 Motorway pic.twitter.com/mrAAqv0SVF
— Paras Bagthalia (@PBagthalia) September 13, 2021
A separate clip shared online showed a motorist attempting to drag a protester out of the road as tempers flared during another incident before a police car turned up.
In total, 92 people were arrested in connection with the protests.
Essex Police confirmed 12 people were held on suspicion of highways obstruction after the road was blocked near junction 31 for Lakeside.
The force said it received a call shortly before 8.15am and the road was reopened by 10.45am after officers “worked to resolve the situation quickly and safely”.
Hertfordshire Police later confirmed it had arrested 18 people, while London’s Metropolitan Police said 14 people had been detained and Kent officers reported a further 12 arrests.
Surrey Police said the force had also arrested 36 people on suspicion of public nuisance and wilful obstruction offences.
Insulate Britain is calling on the government to “get on with the job of insulating Britain’s homes”.
The new group tweeted: “We are disrupting the M25. Why? We are demanding the government and @BorisJohnson create hundreds of thousands of jobs, lower our emissions, and save lives.”
Edmund King, president of the AA, said the demonstration had caused extra emissions from delayed vehicles.
He added: “This action is not only incredibly dangerous in potentially putting lives at risk, but it also backfires in environmental terms by causing more delays and more vehicle emissions.
“These are some of the busiest sections of the M25, where tens of thousands of drivers will have been affected, and has a negative knock-on effect on economic activity.”