“The thing about this guy, is that he has been in cahoots with the fossil industry, and now he’s been nominated to be secretary of state. I’d like to ask him why he thinks he should be secretary of state.”

So spoke Kiran Oommen, one of 21 youngsters who are set to question under oath Rex Tillerson, Donald Trump’s nominee to be America’s top diplomat.

Lawyers for the young people, who are suing the US federal government to try and force it to take action against climate change, want Mr Tillerson to reveal just what he and, the industry he worked for, knew about climate change and the impact of fossil fuels in warming the planet. The lawsuit also targets energy industry groups – the American Petroleum Institute (API), the National Association of Manufacturers (NAM), and American Fuel & Petrochemical Manufacturers (AFPM) – who the youngsters claim worked to stop the government from taking action.

Lawyers for the young people have sought to get the testimony from Mr Tillerson on 19 January, the day before be is due to become US Secretary of State. They hope to prove that energy trade associations have known about the dangers of climate change since the 1960s and worked to cover them up.

The young people are being supported in their action by the Our Children’s Trust, an Oregon-based organisation that is trying to use the legal system to protect the earth’s atmosphere for future generations.

“Rex Tillerson is one of the most knowledgeable executives in the fossil fuel world on the role of his industry alongside our federal government in causing climate change and endangering my youth plaintiffs and all future generations,” said Julia Olson, one of the lawyers, and the executive director of the trust.

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“We intend to use his deposition to uncover his and others’ culpability, on behalf of these defendants.”

Mr Oonerman, 19, from Eugene, told The Independent, he was driven to act by what he called the disconnect between the way the federal government behaved, and the way it was supposed to act. “They were put in place to protect the people,” he said.

The legal action claims the federal government has violated the young people’s constitutional right to life, liberty, and property, and their rights to vital public-trust resources, by promoting a fossil fuel-based energy system for decades, despite being aware of the dangers it posed.

The trust said that Mr Tillerson, who was an executive member of the American Petroleum Institute, would be asked about his company and industry contributing to global environmental damage.

It said that one of Exxon’s senior scientists had written in 1977 that “the most likely manner in which mankind is influencing the global climate is through carbon dioxide release from the burning of fossil fuels”.

Another of the young plaintiffs, Alex Loznak, 19, a student at Columbia University, said: “I was shocked when students at Columbia Journalism School uncovered ExxonMobil’s deep knowledge of climate change as early as the 1970s. What’s even more disturbing is that the federal government firmly knew about climate change in the 1950s.”

Mr Tillerson has not personally commented on the lawsuit. However, the three trade groups have denied the allegations levelled by the young people and joined with the federal government to oppose the action.

Sidley Austin, the law firm representing the three trade groups, did not immediately respond to questions on Monday.

Mr Tillerson was chairman and chief executive officer of ExxonMobil from 2006 to 2016 ( AP )

Speaking from Oregon, Ms Olson said the group believed there was persuasive evidence that not only had the fossil fuel industry been aware of the link to climate change, but had lobbied the US government against taking action.

She said that as of 20 January, Mr Trump would automatically become a defendant in the case, because of his position as president.

Asked as to whether she believed the next president would support a move away from fossil fuel, she said: “Mr Trump is unpredictable because of everything he has said.”

She added: “My message to Trump is that we are committed to this case and determined to hold the government accountable.”

Last November, the youngsters and their lawyers received a major boost when a federal judge blocked attempts by the federal government and the trade groups to dismiss the lawsuit.