Do you ever feel frustrated by the amount of airtime that our celebrity culture gets?
I think it’s sad that people need to live their lives through other people’s. There’s no excuse for it, you can hop on a plane now and have your own extraordinary experience. I think we’re living through a unique period – our ancestors never had the oppurtunity to travel like we do now, and I suspect and fear that our generations to come will not be able to travel the way we can now.

What do you think about carbon offsetting?
I think it’s an attempt to legitimise unsustainable behaviour. I hope that because I only fly long-haul for work and what I’m filming is about how the world is changing, that is some kind of justification for the trips we do. I live a fairly frugal life in Britain but even so it’s going to be the equivalent of a small African town, that’s the reality of being a Brit. It worries me when I’m in Bangladesh, seeing people lose their homes because of climate change. I think one of the trends in travel in years to come will be that people will try and get more out of their trip and have a purpose for the journey, whether it’s finding some remote community that’s desperate for 10 sets of spectacles and taking those with you, or whatever. There are ways of making a journey more interesting and justifiable.

Your new BBC series, Tropic of Cancer, is airing this month. Did you enjoy filming the last of the trilogy?
It’s by far the biggest journey and project I’ve ever done – it’ll be two years roughly from beginning to end. I travelled in 18 countries, to some of the most remote parts of the world, from the most remote island chain on the planet to parts of south-east Asia where they had never seen foreigners before. Hopefully you get a snapshot of life at the edge of this most fantastic and fantastical part of our planet. The Tropics have the most biodiversity, two-thirds of the human population of the world and the greatest concentration of human suffering, so for me it’s an exploration of the most interesting part of the world.

What was your highlight?
Obviously every leg of the journey had its charms and delights, but travelling across parts of the Sahara was jaw-droppingly beautiful. I remember we were camping at a really remote edge of the Sahara, we got a fire going and our guide was cooking some bread in the sand, and this Tuareg nomad appeared out of the darkness and came and sat by our fire. The code of the desert is if you see a fire, you can go over and share food. He ate with us and then just went off into the darkness.

Have you ever got into trouble for anything you’ve reported?
I was arrested by the KGB once when we were filming for Places That Don’t Exist. We were in Transnistria, which is a breakaway state between Moldova and Ukraine, and were caught red-handed creeping through bushes trying to film a secret Russian military base. The KGB turned up, took us away for questioning and then locked us in a cell. I was pretty worried because we were in a country with no diplomatic links with Britain. Luckily I had told one of our guides a couple of days before that my distant ancestor supposedly was involved with the architect Christopher Wren – my family’s one claim to fame, and the guide turned up at the KGB headquarters and said, ‘What are you doing? He’s related to the Queen of England!’ So the KGB let us go in the middle of the night and gave us cap badges as a souvenir; it was bizarre.

Have there been any moments travelling when you’ve feared for your life?
I’ve been to Mogadishu in Somalia which is perhaps the most dangerous place in the world for a white European and I was very scared – there are people with guns everywhere. But most frightening moments happen when we’re on the road. We’ll meet a tree trunk or a bull and the drivers are usually driving too quickly. When we were in Laos, we were driving with a de-mining charity and the driver pulled over because he saw some rocks in the middle of the road, which turned out to be a cluster bomb! There have been lots of times that I’ve feared for my life but for some reason when you’re filming you feel like you’re in a forcefield. I definitely feel braver and less vulnerable when the camera’s rolling.

Do you have any tips for getting underneath the surface of a culture?
I would say walk, go beyond the gates of your all-inclusive hotel. Walking will mean you interact with where you are and you’ll meet people.
I was walking around Taipei in Taiwan, and it was only by walking that I noticed that they paint their electricity substations on the side of the road with murals. Taiwan is so well-run that they beautify their country to that extent.

Often potential risks can put people off travelling to lesser-known locations; do you have any advice for staying safe?
My number one piece of advice is to wear a seatbelt. So often people go abroad to a country where you don’t even have to pass a driving test and think it’s fine not to wear a seatbelt. In my job I am more likely to die in a traffic accident than anything else, and the same goes for most people abroad. Generally the world is a safe place and the dangerous parts are easily identifiable. Go with your gut feeling, don’t walk around with your gold bracelet dangling out, try and blend in and walk with a purpose.

Where, if anywhere, remains on your wishlist of places to visit?
West Africa, Russia, Japan and Canada. I’ve been to nearly all the former Soviet countries but not the motherland. I want to go to Japan because everyone says it’s like visiting another planet, Canada because it’s big and beautiful, and I would quite like to do more outdoorsy stuff, and West Africa because that part of the continent I haven’t visited and it sounds amazing.

If you could live anywhere in the world where would it be?
It would be between Denmark and Greece. I judge where I’ve been by Somalia in terms of it being one of the most conflict-ridden, corrupt states, in contrast with Denmark, which I believe is the least corrupt and happiest. My wife is half-Danish and they’re lovely people, and I love Greece too – it’s beautiful with a stunning coast, fantastic food and ancient culture.

What do you miss most when you’re travelling?
Family and friends, home, Hampstead Heath, Radio 4 and Innocent drinks, probably in that order.

Do you see yourself making travelogues for the forseeable future?
I’d like to, it’s a fascinating and fortunate job. I get to explore the world, learn about our planet and meet really wonderful people. It’s been an amazing experience and a privilege.