Five Insulate Britain activists have been jailed after breaching a High Court injunction by protesting on the M25 last year.
Eleven others received suspended prison sentences after taking part in demonstrations between different junctions of the motorway on October 29.
National Highways brought contempt of court proceedings against protesters, accusing them of breaking an injunction granted in September aimed at curbing blockades.
Lord Justice William Davis, sitting with Mr Justice Johnson, sentenced protesters at a hearing in the Royal Courts of Justice on Wednesday afternoon.
Theresa Norton, 63, Diana Warner, 62, El Litten, 35, and Steve Pritchard, 62, glued themselves to the court steps in defiance of the proceedings on Tuesday. All four were jailed for between 24 and 42 days.
Ben Taylor, 27, was jailed for 32 days.
The remaining protesters were given suspended sentences but will be jailed if they breach the injunction within the next two years.
Biff Whipster, 54, Stephen Gower, 55, and Paul Sheeky, 46, were given 24-day terms; Ruth Jarman, 58 and Rev Sue Parfitt, 79, were given 30-day sentences; Ben Buse, 36, received a 40-day sentence; David Nixon, 35, Gabriella Ditton, 28, Indigo Rumbelow, 27, and Stephanie Aylett, 27, were given 42-day terms; and Christian Rowe, 24, received a 60-day sentence.
On Wednesday morning, the court building briefly saw more protest action after a large banner was unfurled from a balcony inside the main hall bearing the words "Insulate or die".
A number of High Court injunctions against Insulate Britain's road blockades have been previously granted to National Highways and Transport for London to prevent their disruptive protests.
Lord Justice Davis said that the judges' ruling was not about reviewing the M25 injunction.
"We are simply concerned with the fact that an order was made by a court and a court order is to be obeyed," he said.
"The rule of law would fall apart if people decided which orders and which laws they chose to abide by and which they did not."
He said they were asked by Mr Pritchard earlier on Wednesday to "exercise moral courage and imagination".
The judge added: "I emphasise, we are here to enforce a lawful court order ... what we are engaged in is in no sense a value judgment about the merits or demerits of government policy in relation to climate change.
"This is a court of law, not of public policy."
The judge said the four people who glued themselves to the steps of the court were not being punished for those actions, but he added that it "does demonstrate their anxiety to continue the protest with which we are dealing today".
Ms Norton, Dr Warner, Ms Litten and Mr Pritchard appeared in the courtroom dock after being taken into custody on Tuesday evening, alongside Mr Taylor who is still serving a six-month prison sentence imposed in November for a different injunction breach.
Lord Justice Davis noted that all the protesters admitted to being in breach of the injunction, adding: "They all accept they did protest quite deliberately in an effort to disrupt the traffic on the motorway."
He acknowledged they wanted to "bring to public attention their very strong views about the need to attack climate change with particular reference to insulating homes in this country and fuel poverty".
This was a "legitimate basis" for protest, the judge said, but not to do so in breach of a court order.
Wednesday's ruling is the third time the High Court has handed out sentences to protesters over breaches of the court order, following hearings in November and December.
Nine of those in court had previously been committed for contempt in relation to the M25 order.
Mr Taylor's further sentence was objected to by a man sitting in court on Wednesday, who was asked to leave by court staff.
"He's already served three months. It's outrageous, he's in prison now," the man shouted.
Insulate Britain supporters cheered and applauded at the end of proceedings as those in the dock were led away.
On Tuesday, three activists, Arne Springorum, 49, Liam Norton, 37, and Jessica Causby, 25, were told they were "free to go" after judges ruled they had not breached an injunction during protests the M25 on November 2.
Insulate Britain, an offshoot of environmental activist group Extinction Rebellion, was founded last summer.
It is calling on the government to fully fund the insulation of all social housing by 2025 and the low-energy, low-carbon retrofit of homes by 2030.
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