Eighteen of the group pleaded guilty in Newcastle Local Court on Tuesday to interfering with the loading of coal.

All received good behaviour bonds, while only one was convicted.

The court heard most of the group were students in their early 20s who travelled from Melbourne to participate in the Frontline Action on Coal protest.

The protesters were among a group of 26 people who shut down the Hunter Valley coal chain for six hours on the morning of Saturday, September 15.

Several of the protesters, who were dealt with individually via phone link, told the court the pending charges had cost them employment and study opportunities.

Magistrate Sharon Crews told the protesters their right to protest about climate change was not in question, but it must be done so within the confines of the law.

"We are very fortunate to live in a country where people have the right to express their views and protest publicly, but businesses also have the right to conduct their business until they are told to stop," she said.

Christian Hearn, who represented 13 of the group said he was pleased with the result.

"This was a committed group of young people who are deeply concerned about the threat that climate change poses to humanity, and who have the integrity to do something about it," he said.

"Their motives were rightly acknowledged in the leniency of the outcomes today."

Drew Hamilton, who represented five of the protesters, said the verdicts reflected the court's view that while citizens had the right to protest they should do so in a legal and safe manner.

A Frontline Action on Coal spokeswoman said the activists sought to push back against the narrative that Australia did not have a responsibility to respond effectively to climate change because of its relatively small population.

"These 19 people had tried everything else. They are contributing to their local community in all kinds of different ways but the reality of the situation is that no one listens until you are disruptive," she said.

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