Prince Charles on family, future grandchild

UNDATED (NBC) -- Prince Charles sat down with the BBC inside his official London residence: Clarence House.

A longtime environmentalist, the prince said becoming a grandfather gives him greater motivation to protect the world.

“And I don't want to be confronted by my future grandchild saying 'why didn't you do something?' so clearly now that I will have a grandchild, it makes it even more obvious, to try and make sure we hand them. Leave them something that isn't a totally poisoned chalice,” said Prince Charles.

He talked about younger son harry ho is still stationed on the front lines in Afghanistan and has been a target of terrorists.

“Certainly every night I go to bed I worry. But you know he loves doing what he's doing. He's brilliant at it,” he said.

The prince said having a son in the service helps him relate to many families.

“I do know, yes I constantly meet the families of those who've lost their sons or husbands or brothers or sisters. I have some understanding at least of what they go through,” he said.

When asked about becoming a grandfather he said it makes him feel old, but he is overjoyed. Kate is expected to give birth this summer.