Prince Charles has made some very rare comments about his sons, Prince William and Prince Harry as he writes an exclusive essay for American publication, Newsweek.
The Prince of Wales will be covering the January issue of the magazine where he sets out his plans to combat climate change. During the interview, he spoke of his pride in both of his sons as the royal brothers both work to solve the issue with their own initiatives. The heir to the throne wrote: "As a father, I am proud that my sons have recognised this threat.
"Most recently, my elder son, William, launched the prestigious Earthshot Prize to incentivise change and help repair our planet over the next ten years…"
WATCH: Prince Charles introduces Sky Kids climate change documentary
He added: "And my younger son, Harry, has passionately highlighted the impact of climate change, especially in relation to Africa and committed his charity to being net zero."
MORE: The Queen makes rare comment about Lilibet during Christmas Day speech
READ: Prince William breaks silence during Christmas break after sad death
The royal will speak of the importance of taking action now, as he said: "The eyes of our children and grandchildren are judging us. As we enter a new year, there is not a moment to lose."
The royal praised William for the Earthshot prize
Nancy Cooper, the global editor of Newsweek, spoke of her happiness of Charles sharing his words, as she said: "We are proud to publish the Prince of Wales' powerful appeal, calling on all of us to address this crucial challenge.
"Given his decades of engagement on this issue, he can speak with deep knowledge and real authority."
INSIDE: Duchess Camilla and Prince Charles' country estate is the ultimate winter wonderland – photo
MORE: 12 royal parents and their lookalike children - see the most striking photos
Later on in January, Newsweek will also be launching its own royal podcast, titled Royal Report.
The Duke of Sussex is also passionate about the environment
The Prince of Wales is renowned for his environmental passion projects, and that's even reflected in his home, Clarence House.
His official website explains: "Around half of his office and domestic energy use comes from renewable sources such as woodchip boilers, air-source heat pumps, solar panels and 'green' electricity."
EXCLUSIVE: 4 unusual things Prince Charles can't go without at royal banquets
MORE: Prince Charles pays tribute to Prince Philip during visit to 'special place'
In 2011, Prince Charles had 5.6kW solar power system installed at the London property.
The royal's full essay will be published on Newsweek and will be the cover story of the domestic and international issues of the print magazine, available on 14 January.
Make sure you never miss a ROYAL story! Sign up to our newsletter to get all of our celebrity, royal and lifestyle news delivered directly to your inbox.