Skyscraper greenhouse, rising to meet the world food challenge

More from less. That’s one of the ‘global megatrends’ the CSIRO has identified in its 2012 revision of how the shape of our future world will change the way we live. “Companies, governments and communities will discover new ways of ensuring quality of life for current and future generations within the confines of the natural world’s limited resources,” says the report, released today.

And as if to prove the CSIRO right, an upwards-thinking Swedish social enterprise is doing just that. The group, Plantagon, has come up with a design for high-rise greenhouses, which it will build in urban areas, and which will be able produce thousands of tonnes of food a year – enough to feed up to 30,000 people, according to Anders Modig, the company’s global sustainability director.

How will they work? According to a report on BusinessGreen, the food crops will be grown on a spiral running through the heart of the building, moving slowly downwards over two to three months before being harvested at the bottom. The building’s temperature, and levels of carbon dioxide and water vapour will be tightly controlled to increasing the growing area and yields, and to minimise the need for pesticides.

Carin Balfe Arbman, Plantagon’s head of communications, says the company would use the excess heat from buildings to heat the greenhouse, while carbon dioxide from outside will be turned into oxygen. “And you can make biogas from what comes out of the greenhouse,” he adds. It is also suggested that the high-rise greenhouses could help purify water if linked up to sewage networks, and could become part of Sweden’s district heating systems.

And if you think that this all sounds like so much science fiction, BusinessGreen reports that Plantagon has already begun building its first greenhouse tower – a 54 meter high cone in the city of Linköping, about 200km southwest of Stockholm, which is set to be complete in 2014.

This building – which will start by growing pak choi, because such leafy green vegetables are best suited to the greenhouse, and also in the hope of attracting the Asian market – will also incorporate office space, which should help it become profitable before any vegetables are sold.

Modig says the greenhouses could also be combined with shopping area. “Maybe just build it on the top, so the vegetables come right to the supermarket,” he says. And as for height, the sky’s the limit, he says.

And the cost? BusinessGreen reports that much of the 200 million Swedish Krona ($A29.6 million) price for the building has been covered by Plantagon and its backers, the Onondaga Nation – a politically independent American Indian tribe from New York State, traditional owners of the Onondaga County – who were instrumental in founding the company with ethical business guru Hans Hassle in 2008.