The Future Familiar: Jeanette Bresnihan, The Alphabet Network (Dublin: Wolfhound, 2000).
One issue with some children's sf is that one wonders why it's set in the future at all. The Guardians of Time, at least for the first half, could have been set in the nineteenth century--isolated child longs for school. It certainly didn't feel any later than 1950--children's science fiction seems to be the last bastion of the full-time housewife, it's generally much more sexist than non-sf for children.
The Alphabet Network is a particularly pointless example of futurism, although it is pleasantly told.
Two children travel from a destroyed Europe to find refuge with their Grandfather in the west of Ireland, the only country left unspoiled by eco-wreckers. With them they have a box containing something terribly important for their grandfather, but of which they have no knowledge.
On the way, they are passed like parcels (no childish independence or ingenuity here) from hand to hand among the members of the Alphabet Network, a group of now elderly eco-terrorists each of whom carries an animal image from the Book of Kells (animals illustrate a letter on each page of the Book of Kells). They are hunted by a man in a white suit. When they reach their grandfather, the box turns out to contain photographic evidence of an Irish senator’s corruption.
I had expected maybe a formula for reinvigorating European soil, genetically modified seeds that would survive the pollution. Something that mattered in the context of the future which Bresnihan creates (rather effectively it should be said). Instead I found myself wondering why they didn't use the mail.