Biff Whipster, from Canterbury, was among seven members of the climate action group who appeared at the High Court in London after breaking court injunctions and being in contempt of court.
The group were all given suspended prison sentences while a further two people will serve time in prison and costs of £39,000 in total were awarded against the defendants.
Mr Whipster, 54, who was being charged with contempt in relation to two breaches of the government’s M25 injunctions, was given a three month prison sentence suspended for two years.
"Each day this government fails to act on these extinction events brings societal collapse in the UK a day nearer," he said.
"Your pension pots will go, house prices will collapse, prices sky-rocket but wages don’t keep up.
"Then it gets real... panic buying, but the shops can't restock their shelves, food runs out, people go hungry.
"Hospitals have no medicines. People start killing each other... and where's our government in all this?
"Nowhere to be seen. Our government does not care."
The 54-year-old dad from Canterbury has been arrested 17 times in two months, making him one of the movement’s most prolific ‘offenders’.
The former Post Office business analyst, who gave up the corporate world to lead a “simpler more sustainable life”, now manages on a meagre £700 a month, with £10 a week for “impulse purchases”.
He previously told KentOnline in an interview: “Of course, the thought of prison frightens the life out of me, but I can’t stand by and do nothing when we are at code red for our climate."
Steve Gower, 54; Ruth Jarman, 58; Richard Ramsden, 75; Stephen Pritchard, 62; Paul Sheeky, 46; and Reverend Sue Parfitt, 79, were each given a two month sentence suspended for two years.
This was on condition they do not break the government’s motorway injunction in that time.
Dr Ben Buse, 36, who has served 28 days of a four month sentence on an earlier charge of contempt of court, was ordered to serve a further 30 days consecutively.
He is still eligible for early release so will likely serve two-and-a-half months in total.
Dr Diana Warner, 62, who yesterday failed to attend court while she blocked a train heading for Drax power station, accepted her guilt and was given a two month prison sentence.
Sentences were handed down by Lord Justice Dingemans and Mr Justice Johnson today after National Highways took legal action against protesters.
The seven were ordered to pay costs of £5,000 each, with the exception of Biff Whipster who must pay £6,000, Ben Buse who must pay an additional £2,500 on top of costs from his earlier hearing and Steve Gower who has been charged a lower tariff of £500.
The group were shocked at the "leniancy" of the sentences which were in contrast to the jail terms of between three and six months handed out to Insulate Britain members on November 17.