Alastair Bonnett’s contention is that we are living in a period when islands have acquired greater significance than perhaps at any time in history – whether culturally, politically, economically, militarily or simply as slowly drowning canaries of climate change. His book guides us on a knowledgeable world tour of different types of islands, much enhanced by self-deprecating accounts of his own often shoestring visits. His stories can be sobering, as in the case of the San Blas Islands off the north coast of Panama, which are the last vaguely autonomous stronghold of the indigenous Kuna people. There is only limited hope for the Kuna’s future, a consequence of political ineptitude and the sheer difficulty of survival faced by people on all smallish islands. The San Blas Islands contrast strongly with the gated and surveilled artificial islands on the other side of the isthmus, which were built by and for Panama City’s super-rich in a one-off defiance of the country’s constitution, which forbids marine estate being sold for private use.

The author’s visits to sites of man-made islands are particularly revealing. Referring to the new tulip-shaped islands being built off the coast of Amsterdam, Dubai’s The World and the Ocean Flower project off the coast of Hainan in China, Bonnett tartly observes that sculpting shapes for aerial photo opportunities is a common weakness of island designers. Many Westerners probably have little idea of quite how huge Chinese artificial island projects are. The Ocean Flower is one and a half times as big as Dubai’s Palm Jumeirah and when completed will host twenty-eight museums (!), fifty-eight hotels, seven ‘folklore performance squares’ and the world’s largest conference centre. Bonnett visits Chek Lap Kok, the artificial island twice the size of Gibraltar that houses Hong Kong’s airport, while also reminding us that Kansai in Japan became the world’s first fully artificial airport island when it was completed in 1994. He doesn’t mention ‘Boris Island’, Boris Johnson’s proposed airport in the Thames Estuary, which seems unlikely ever to be built. If it were, we would probably have to turn to the Chinese for its construction, since they have the requisite technology and experience.

Given Bonnett’s sympathetic discussion of the Scilly Isles, condemned to be both eroded and drowned, it is strange he omits any mention of Rockall, because its legal status has significance for the situation in the South China Sea. Britain views this uninhabitable stack in the Atlantic some 180 miles west of Soay as part of Scotland. The United Nations Convention on the Law of the Sea (UNCLOS), to which Britain is a signatory, stipulates that ‘rocks which cannot sustain human habitation or economic life of their own shall have no exclusive economic zone or continental shelf’. In keeping with this, the UK has not tried to extend its exclusive economic zone a further two hundred miles from Rockall out into the Atlantic. Instead, it contents itself with a claim to the customary twelve miles of territorial waters around the island. Contrast this with China’s activities in the South China Sea, where over the last twenty years quite uninhabitable coral reefs have been built up with dredged sand in order to create military runways and port facilities, leading to an international legal impasse. China, with its ‘nine-dash line’, claims practically all the South China Sea, notwithstanding historical claims by neighbouring countries, especially the Philippines, which has long maintained semi-permanent fishing communities on some of the Spratly Islands to the west of Palawan.

Despite being a signatory to UNCLOS, China simply opted out of recent hearings of the case at the International Court of Justice, which found for the Philippines. What is to be done when a participating country just goes its own way? Legally speaking, much of the South China Sea remains in limbo. But as far as China is concerned, its extension of territorial control is a fait accompli. Not so many years ago the United States would have challenged this power grab; now no longer.

Despite skimping slightly on such legal matters, Bonnett expertly covers the different kinds of islands worldwide. He is particularly good on geophysical explanations for why and how they can surface suddenly, like Surtsey off the coast of Iceland, or bob up and down, like Graham Island between Sicily and Tunisia, which has appeared and disappeared several times since the mid-19th century. I slightly wish he had spent more time on vainglorious private projects like the late Lazarus R Long’s New Utopia. This was intended to be a state built on piles over reefs in international waters in the Caribbean. According to new-utopia.com (well worth a look), Prince Lazarus has been succeeded as the ruler of the principality by his relict Princess Maureen Howard Long. This and similar projects, such as Norman Nixon’s gigantic Freedom Ship – a plan crafted in the 1990s to create a floating city – are attempts by wealthy American visionaries of the usual right-wing libertarian tendencies to construct kingdoms (so much for republicanism!) for the like-minded and wealthy. Freedom Ship doesn’t yet exist, but MS The World does and plies the oceans like any cruise ship. This vessel is basically a mobile island for those who wish to be free of governmental interference, including taxation. The World’s website says that ‘potential buyers must prove minimum net worth of $5 million to purchase an apartment’ and that acquiring one of the ship’s 165 ‘residences’ is ‘not for the faint of wallet’.

All in all, Bonnett has written a most readable and sympathetic account of the various guises islands can take around the world and rightly points out the ecological consequences of human building projects. He notes the destruction of many sandy islands and sandbanks to feed the global appetite for concrete, saying that ‘nearly all modern artificial islands have a deleterious impact on the environment’. He adds a telling statistic: ‘In just three years, between 2011 and 2013, China used more concrete than the US did in the entire twentieth century.’