Paul Salopek walking 400 kilometres across the remote Kyzyl Kum desert of Uzbekistan en route to China. Courtesy John Stanmeyer / National Geographic  
Paul Salopek walking 400 kilometres across the remote Kyzyl Kum desert of Uzbekistan en route to China. Courtesy John Stanmeyer / National Geographic  

19,000 kilometres and counting: why this man is walking from Ethiopia to Argentina