Climate change is causing "untold horrors" across the world, the Prince of Wales has said.
In a wide-ranging interview with Prince Harry, who was guest-editing BBC Radio 4's Today programme, he warned that technology "can't solve our relationship with nature".
When asked by his son to pick one issue to focus on next year, Charles said over the years there have been a "whole lot" of things he has tried to focus on that he thought needed attention.
"Not everyone else did, but maybe now some years later they are beginning to realise that what I was trying to say may not have been as dotty as they thought," Charles said.
"The issue really which has to go on being focused on, big time I think, is this one around the whole issue of climate change.
"Which is now, whether we like it or not, is the biggest threat multiplier we face because what is happening now is what I was dreading.
"Which is we are having to deal all the time with the symptoms that are springing up all round the world, and they are diverting us off down all these different channels to try and deal with ghastly conflicts and humanitarian and natural disasters, and goodness knows what else.
"At the root of it all, much of it, is climate change which is causing untold horrors in different parts of the world."