The king was listed as attending the Cop27 opening ceremony despite not attending the UN climate summit.
Downing Street acknowledged last week that the monarch could have joined international delegates in Egypt had Prime Minister Rishi Sunak been in office earlier in the year.
When Liz Truss was prime minister, a “unanimous agreement” was reached that the king should not be present after his office sought advice from the government.
The title of the UN Climate Change (UNFCCC) live stream for the start of Monday’s summit was as follows: “Opening ceremony with speeches by the President of the Republic, the SG of the UN, the King of the Kingdom United Kingdom, of the ruler of the United Arab Emirates”.
Egyptian President Abdel Fattah El-Sisi, UN Secretary-General Antonio Guterres and UAE President Sheikh Mohamed bin Zayed Al Nahyan all appeared and spoke in person at the resort town of Sharm el -Sheikh, on the Red Sea, but there was no appearance – virtual or otherwise – of the British monarch.
Buckingham Palace said the King was not expected to address Cop27 via video or any other means, and the stance had not changed.
The UNFCCC has yet to comment.
Charles, as Prince of Wales, spent decades campaigning passionately on green and environmental issues.
It has been widely reported that the King, who addressed last year’s Cop26 summit in Glasgow, had hoped to attend in person.
However, it is understood that after seeking the advice of Ms Truss, then Prime Minister, as is customary for royal visits abroad, it was agreed that he would not go.
But a Downing Street spokeswoman said last Thursday of the possibility of Charles attending: ‘We recognize that had the Prime Minister been in office earlier the situation might have been different, but that is not feasible on the logistics plan at this late stage.”
The King, however, hosted a reception at Buckingham Palace on Friday ahead of the conference, hosting leaders, business figures, environmentalists, Mr Sunak and fashion designer Stella McCartney.
Mr Sunak, who is attending the global rally after a U-turn, told Palace guests that the world will experience “more human suffering” if we continue to let “climate change ravage our planet”.
In 2021, Charles told Cop26 that the world is tired of talking and commitments need to be put into practice.
The late Queen delivered a video message at the Cop26 welcome reception, after stepping down while resting on doctors’ orders.
She urged world leaders to work together in a “common cause” to tackle climate change, and said she hoped the summit’s legacy would be for them to recognize that “the time for words has now passed. action time”.