Section A The world has changed dramatically since Thomas Malthus’s work ‘An Essay on the Principle of the population’, first published in 1798, argued that by the mid-1800s the unrestricted expansion of the human population would outgrow the agricultural land available to supply humanity with food. Over 150 years have passed since this theoretical milestone but mankind, admittedly somewhat more cramped, is still expanding and will continue to do so.

Section B The impact of unfettered population growth is clear for all to see. Urbanization is now a more evident worldwide phenomenon than previously as even greater numbers of people drift from rural areas to vast cities all over the world like Tokyo, Mexico City and Mumbai (26.4 million, 18.4 million and 18.1 million inhabitants in 2000 respectively) in their quest for a better life. These mega-cities, i.e. conurbations with an estimated population of more than 10 million people, are springing up in every continent. Now teeming with humanity, they are hungry for one increasingly valuable resource: land.

While developments in agricultural technology ensure humanity may be able, by and large, to feed the people flocking to these great metropolises, the expansion of the human race is fuelling an unprecedented appetite for real estate. Space, whether it be for personal or public use, corporate or national, human or flora/fauna is now at a premium as we move into a new century. Not only is more land required for accommodation, but also for a wide range of infrastructure facilities. Transport systems including roads within and between cities need to be constructed or upgraded to create motorways; green fields are turned into airports; the virgin forest is stripped to provide food and firewood. In poorer regions, this newly exposed land becomes desert completing the cycle of destruction.

Section C Hitherto, the most common practice for the utilization of expensive space for living and working has been to build upwards; hence, the demand for ever higher buildings, both apartment and commercial, in major cities like New York, Shanghai and Singapore all vying with each other for the tallest buildings. There has also been a tradition for building underground, not just for transport systems, but for the storage of waste, depositories for books etc. as in London, where The British Library housing millions of books has been built largely underground.

Recent years have seen more novel construction developments around the world. In the past, in many countries, Holland and the UK included, marshes and floodplains have been reclaimed from the sea. Like the city of Venice in Italy, housing complexes and even airports have now been constructed off-shore to amazing effect. In Japan, Kansai International Airport has been built off-shore on a man-made island at vast expense and in Dubai, a very imaginative and expensive housing complex in the shape of a palm tree is being built just off the coast on land created by a construction company. However, these and other developments are at risk from rising sea levels as a consequence of global warming.

Section D But where will the human race go when planet earth is full? There have been many theories put forward about the human population moving to outer space. Marshall Savage (1992, 1994), for example, has projected that the human population will reach five quintillions throughout the solar system by the year 3000, with the majority living in the asteroid belt. Arthur C Clarke, a fervent supporter of Savage, now argues that by the year 2057 there will be humans on the Moon, Mars, Europa, Ganymede, Titan, and in orbit around Venus, Neptune and Pluto. Feeman Dyson (1999) favors the Kuiper belt as the future home of humanity, suggesting this could happen within a few centuries.

Section E Habitation in outer space in huge stations is no longer just a dream, but a reality. A permanent international space station now orbits the earth. The first commercial tourist recently went into outer space with more trips planned for the near future. This is only the beginning, but the development of space hotels is not far-off. There is no knowing where mankind may end up. But the ideas about off-world habitation are not fanciful and I am sure I am not alone in fantasizing about summer holidays spent watching the moons rising in some far-flung planet or on a floating hotel somewhere on the Andromeda nebula.