"The year 2035 will be close to the centenary of the 1937 Hindenburg disaster, when a hydrogen-filled airship caught fire after a static spark ignited its onboard gasbags."
OTOH, The Graf Zeppelin made dozens of trans-Atlantic crossings between 1928 and 1937 as well as a round the world trip in 1929. It was a little slow for long distance travel -- max speed 117kph (a bit over 70mph). I imagine a modern version would be substantially faster and hopefully less likely to self-destruct. Likely not what you'd want to fly from London to Melbourne, but for shorter trips like Dublin to Paris or Washington,DC to Boston, it'd likely be a lot faster than a train and not much slower than a jet once airport delays are taken into account. And the economy seats might even be an appropriate size for an adult human being.