People
Perhaps it's my natural pessimism, but it seems that an awfully large part of travel these days is to see things while you still can. In A Sunburned Country
— Bill Bryson

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
Travel is described as increasingly motivated by fear that places or experiences may not remain available. The speaker openly frames this as possible pessimism rather than proving that particular destinations will disappear. In A Sunburned Country is the retained title note.
Context reviewed