By Jeremy Cooke

BBC News, New York



Is this how farms will look in the future?

Downtown Manhattan is hardly a place you would associate with agriculture. Rather, with its countless restaurants, cafes, shops and supermarkets this is a place of consumption.

And so every morsel, every bite of food New Yorkers munch through every day must be trucked, shipped or flown in, from across the country, and across the world.

Now though, scientists at Columbia University are proposing an alternative. Their vision of the future is one in which the skyline of New York and other cities include a new kind of skyscaper: the "vertical farm".

The idea is simple enough. Imagine a 30-storey building with glass walls, topped off with a huge solar panel.

On each floor there would be giant planting beds, indoor fields in effect.

There would be a sophisticated irrigation system.

Even if it's not quite natural...you're going to get back the rest of the earth

Professor Dickson Despommier

That means there would be no shipping costs, and no pollution caused by moving produce around the country.

It's all the brainchild of Columbia University Professor Dickson Despommier.

He and his students took existing greenhouse technology as a starting point and are now convinced that vertical farms are a practical suggestion.

Professor Despommier lists many advantages of this revolutionary kind of agriculture. They include:

Year round crop production in a controlled environment

All produce would be organic as there would be no exposure to wild parasites and bugs

Elimination of environmentally damaging agricultural runoff

Food being produced locally to where it is consumed

And, says the professor, vertical farming would allow some existing traditional farms to be returned to natural forests. Good news in a time of global warming.

"Even if it's not quite natural.... a little bit factory-like in terms of its production, here's what you're going to get back: you're going to get back the rest of the earth. And I'll take that any time."

The plan is to make the whole complex sustainable.

Nurturing high rise crops in the "vertical farm"

Energy would come from a giant solar panel but there would also be incinerators which use the farm's waste products for fuel. All of the water in the entire complex would be recycled.

Several hours drive north of the city in upstate New York, Ed Miller's 18,000 apple trees are in full bloom.

Like farmers across the world he has lived through decades of constant change and innovation. But he remains, at heart, a man of the soil.

So what does he think of the virtual farm concept? He is, perhaps, surprisingly positive: ''It looks like a fancy greenhouse," he says. "It's fabulous, it will be very interesting. It will be phenomenal."

For now, vertical farms are a virtual concept. But the scientists insist that the theory is sound.

All they need now, they say, is the money to make this a reality.

Graphics courtesy of Chris Jacobs, Rolf Mohr, and Dean Fowler of machinefilms.com and unitedfuture.com