Campaigners who challenged the lawfulness of the UK government’s climate policies have lost their fight at the High Court.

But the environmental charity, Plan B Earth, and three young people have said they will appeal.

Last month, Tony Crosland, of Plan B Earth, Adetotal Onamade (24), Jerry Amokwandoh (22) and Marina Tricks (20) accused Boris Johnson of breaching his legal duty to take “practical and effective measures” to tackle climate change.

They said he had failed to comply with the Paris Agreement to pursue efforts to limit global temperature rise to 1.5C above pre-industrial levels.

They also argued that the government was breaching their rights to life and family life under the Human Rights Act.

Mr Justice Bourne refused their application for a judicial review and awarded costs against them of £20,000.

He said treaties like the Paris Agreement are not part of domestic law and the domestic courts could not determine whether the UK has violated its obligations:

“the Claimants are using compliance with the Paris Temperature Limit as a test for compliance with Article 2 (and Article 8) [the rights to life and to family life]. The effect is that the Court is being asked to enforce the Paris Agreement, contrary to the guidance in SC [the Supreme Court].”

He also rejected the argument that the claimants were victims of a breach of the Human Rights Act.

Responding to the judgement, Tony Crosland said:

“We are all witness to the devastating impacts of the current level of 1.2C warming [above pre-industrial levels]: deadly famines in Madagascar, east Africa and Afghanistan; wildfires and floods devastating communities and ecosystems around the world, including in the UK.

“Meanwhile, the City of London continues to profiteer from financing a trajectory towards 3-4C warming, which is terrorism for the younger generation and terrorism for the global south. “

“If the courts are bound to ignore the scientific evidence of what is needed to safeguard life, then ‘the right to life’ is no more than an illusion in a political economy which privileges the safety of short-term corporate profit over the welfare of ordinary people.

“We’ll appeal to the Court of Appeal and, from there, to the European Court of Human Rights.”

Jerry Amokwandoh, said:

“Violations of human rights in spite of the evidence are continuing to be legalised. The courts are making themselves obsolete, and empowering our alternatives, global youth tribunals for community self-empowerment.”