It's 4 a.m. and I wake up on a beach on the Sinai Peninsula of eastern Egypt. The moon has set and the mountains of Saudi Arabia just 18 km away across the Gulf of Aqaba are silhouetted against the stars. The camel I rode here is sleeping nearby, and it is still so warm even in late October that a single blanket is all I need. If this is doing my bit for ecological tourism, I'm sold.

I'm here on vacation, but also to investigate ways we can travel in a more sustainable way. You might say it would be better if I hadn't taken this holiday at all — and you might be right. But people are always going to want to get away.

So what can we do to lighten our footprints?