The Raggle Taggle War

It is not too far in the future and some things have worked out as expected - in particular, Renewable Energy is now the main source of power. Whether solar panels, wind turbines, wave power, it's all commonplace and available, and to make it less obtrusive onland, most of the electricity generation has moved offshore, onto giant floating islands, that circle countries like Britain. Meanwhile, the world is not as peaceful and progressive as most people had hoped. Inter-nation tensions are widespread, often breaking out into all-out war. Still, many people in countries like Britain feel safe, since these conflicts seem so far away. It is only when the small nation states start falling like dominoes, that the effect becomes clear - there is a World War underway, and nowhere on the globe is safe.
The hero of this tale is one person who has tried to help set up defences for the islands of Britain, but he is drawn into the conflict, right where the shooting starts, and he finds himself fleeing from the action, undefended and alone.
Meanwhile, the only people who seem safe from these overlapping conflicts are the Gypsies, a new class of mobile adventurers, circling the world in their self-sufficient airships. Only them, it seems, can preserve Civilisation and protect the plant from a grisly end.