A climate activist involved in protests that disrupted the Hunter region's rail network for two weeks has been sentenced to a year in prison.

Eric Serge Herbert was sentenced in Newcastle Local Court to 12 months' imprisonment with a non-parole period of six months.

The charges included causing obstruction to a railway locomotive or rolling stock, attempted hinder working of mining equipment and attempted assist in obstruction of rail locomotive or rolling stock.

He was also fined for $200 for remaining on enclosed land without a lawful excuse.

According to court documents, the 22-year-old resides in Queensland with his parents and has a history of protesting.

He's been charged and convicted of similar offences in the past, including in other parts of NSW, Queensland and the ACT.

Just months ago he was fined a total of nearly $3,000 in Bega Local Court in relation to several charges such as risk and safety of another by climbing building/structure, use intimidation/violence to unlawfully influence person and willfully obstruct officer in execution of duty.

He also has a history of breaching his bail and community service orders.

A police strike force was established last week in response to the ongoing protest action in Newcastle, which impacted coal, grain and passenger trains trying to access the Port of Newcastle.

The NSW Police Commissioner Mick Fuller delivered a stern warning to protesters, announcing that the continued behaviour could result in charges laid under the Criminal Act that carry a maximum penalty of 25 years in prison.

The ABC approached Police Commissioner Mick Fuller to comment on the sentence but he was unavailable.

Group says it's a 'matter of concern'

Climate activist group Blockade Australia held a press conference in Newcastle this morning, describing the police action to stop the ongoing protests as "repression" and an "outrage".

One spokeswoman, 21 year old Hannah Doole, said she was "angry and scared on Sergio's behalf".

"This is a matter of concern for everybody that expresses dissent to the current political system and to politics in this country in whatever form.

"And they have just been sentenced to six months no parole. 12 months imprisonment is an outrage," she said.

Another Blockade Australia representative, 24 year old Jarrah Kershaw, said he did not believe protesters would be deterred.

"Last week, people were threatened with 25 years in jail. And for the next three days, people continued to take action despite that," he said.

Repeat offender

Police facts state that one of the previous incidents Herbert was involved in was at 6:45pm on Wednesday November 10 when he entered the rail corridor near Fenwick Street at Hexham.

He climbed onto an eastbound coal carriage, sat on the coal and began to livestream himself on Facebook.

He was stating that he had "stopped the coal trains that are leading to the world's largest port."

Police observed him for a while before boarding the carriage and finding the activist "huddled down one end" with the back of his right hand superglued to the inside of the carriage.

He refused to respond to requests from police and the ARTC for him to come down from the train, feigning unconsciousness.

After being uncooperative and unresponsive for some time, police removed and arrested him around 10pm.

As a result of Herbert's actions, the Hunter train line was closed for more than two hours, delaying 15 coal trains, four passenger trains and resulting in the cancellation of other passenger train services between Newcastle and Maitland.

Police facts also reveal that the following week, on Wednesday November 17, officers were patrolling an area at Hexham — which is known to be used by protesters to access the Port — when they spotted the Herbert hiding in bushes with another person.

They both ran from police but were later located by the police dog unit and found to be in possession of items intended to be used for protesting.

A third protester was seen in a vehicle nearby, which police searched and located abseiling harnesses, ropes, devices that might be used to lock onto trains or structures and electronic devices.

All three were arrested.