When the duo congratulated him on being a grandfather-to-be the 64-year-old smiled and joked: "I'm feeling very old." The fact that Prince William and Kate Middleton are expecting a baby has made the royal even more aware of the need to take action over concerns about the environment.
"I don’t want to be confronted by my future grandchild and them say ‘why didn’t you do something’, so clearly now that we will have a grandchild, it makes it even more obvious to try and make sure we leave them something that isn’t a total poisoned chalice,” he said.
"I’ve gone on for years about the importance of thinking about the long term in relation to the environmental damage, climate change and everything else. We don’t, in a sensible world, want to hand on an increasingly dysfunctional world to our grandchildren, to leave them with the real problem.
The Prince of Wales also spoke about his concerns for Harry, who is currently serving on the front line in Afghanistan. He said: "Certainly every night I worry. But he loves doing what he’s doing and he’s brilliant at it."
Charles said his worries over his son helped him empathise with families in a similar situation – who have loved ones serving their country within the Armed Forces.
"If you are a parent or relation to a loved one and that person is away in these incredibly dangerous and challenging circumstances, I know you worry all the time," he admitted, adding: "I constantly meet the families of those who have lost their sons, husbands, brothers or sisters… and I have some understanding at least of what they go through."
During the interview, which took place at his official London residence Clarence House, Charles also said he is keen to sustain the positive atmosphere and pride that was felt throughout the UK following the 2012 Olympic and Paralympic Games and Diamond Jubilee.
He said: "These sorts of occasions like the Olympics and the Jubilee bring out the best in people and I do know, from doing investitures on behalf of the Queen, just how many wonderful people there are doing these remarkable things and volunteering the whole time in their own communities. A lot of people don't realise how so many of these people keep the whole show on the road. There is something remarkable in this country I think, about the volunteering spirit."