Has Superman's time come?

As bio-engineers explore how to design our way out of human limitations, Carl Frankel asks if we're poised on the threshold of the ultimate upgrade - to humanity itself.

Hugh Herr lost both his legs below the knee as a teenager when a rock-climbing trip went awry. If you're thinking "Poor man, how does he manage?", you might want to let go of that. Herr gets along just fine.

The director of a bionics research group at the Massachusetts Institute of Technology Herr develops high-tech prosthetic devices that level the playing field for amputees. Or even tilts it their way. He amasses legs the way most people buy shoes.

He has one set of prosthetics for walking, a longer set for jogging and multiple pairs of climbing legs, including one that stretches him to over seven feet tall and another with built-in aluminum claws for Spiderman-like gripping. "I'm able to climb at a more advanced level with artificial limbs. I view [them] as an opportunity, a palette from which to create," he told a TED audience before closing his speech with some zesty Irish dancing.

And then there's the stunning Aimee Mullins, a gifted athlete and model (oh, and double amputee) who walked the London runway in 1999 for fashion designer Alexander McQueen wearing hand-carved wooden prosthetic legs with integrated boots.

Herr and Mullins aren't just extraordinary people: they're walking, climbing, sashaying provocations to conventional notions about disability. They invite us to imagine a time, not far away, when high technology and the physical body are married in ways that endow people with entirely new capabilities. Super-abilities, really - the stuff dreams and comic books are made of.

With their elegant artificial appendages, Herr and Mullins dramatically embody the emergence of what Steve Fuller, a professor at the University of Warwick calls Humanity 2.0: "an understanding of the human condition that no longer takes the 'normal human body' as given." The performance artist Stelarc puts it this way: "We can no longer think of the body as simplistically bound by its skin and containing a single self... We are very much a meat, metal and software system now." In his work he makes this point dramatically, for instance with a cell-cultivated ear, surgically implanted onto his left arm, that for a time had a built-in microphone and transmitted what it 'heard' wirelessly to the Internet.People as discrete flesh-sacks of bones and body organs? That's so ... yesterday. Already, human augmentation is crossing over into sci-fi territory. What the imagination can conceive, technology is increasingly able to deliver.

So: want to have Superman-like strength? The military is developing exoskeletons that strap onto soldier's bodies and do the heavy lifting, literally.

Soldiers in the field typically tote upwards of 100 pounds on their backs. Strap-on exoskeletons could make this vastly less stressful while also reducing the back injuries that are endemic in the army. Want to stave off the cognitive deficits caused by too little sleep? Or how about getting by on four hours a night?

Something called transcranial magnetic stimulation can help you do that.

Or maybe you'd like to move objects using only the power of your mind? It's possible - and you don't have to be Uri Geller. In 2011, the Guinness Book of World Records issued an award to the NeuroSky MindWave, a brainwave reader, for the "heaviest machine moved using a brain control interface."

The awardwinning team used such a method to steer an industrial crane that hoisted a Volkswagen off the ground.This is seriously mind-bending stuff - and other organs are getting involved, too. Soon to come, from the same company that brought you the MindWave: an electrocardiogram chip that lets you control your electronic devices using your heart energy. That's right, your mobile will feel the love.

And this is just the beginning. As progress accelerates across materials science, robotics, neuroscience, biology, artificial intelligence, genomics and a host of other disciplines, human capabilities can be expected to emerge that seem utterly fantastical today.

Meanwhile, back on centre stage, there's this thing called the sustainability crisis that urgently needs our attention. To date, two broad solution paths have been pursued.

The first is resource efficiency. You know the drill: reduce, re-use, recycle, lay off the carbon. The second - which we may come to in any case if the first fails - is geoengineering: manipulating the planet's natural systems to remove carbon dioxide, or deflect solar radiation, on a grand scale.

People like Herr, Mullins and Stelarc point toward a third way. Instead of re-engineering the planet, let's try re-engineering the human! Worried about the size of the human footprint? Then shrink it - literally.

This isn't just wordplay. In an article scheduled for publication in the journal Ethics, Policy and the Environment, academics S. Matthew Liao, Anders Sandberg and Rebecca Roache propose that we consider addressing climate change by building a smaller human.

"We need a certain amount of food and nutrients to maintain each kilogram of body mass ... Larger people also consume energy in less obvious ways. For example, a car uses more fuel per mile to carry a heavy person than a lighter person; more fabric is needed to clothe large people than smaller people" - and so on.

The authors provide a short list of ways to do this, including lowering human growth hormone levels. Speaking to The Atlantic, Liao acknowledged that "People might resist this idea because they think there is some sort of optimal - the average height in a given society, say. But, I think it's worth remembering how fluid human traits like height are.A hundred years ago people were much shorter on average, and there was nothing wrong with them medically."

Indeed, we rose to our present height in part by consuming so successfully: the same aptitudes which have, arguably, placed unprecedented pressure on natural resources.Still, if a 'shrink to fit' approach is too fantastic or dubious a vision, there are other human engineering possibilities cited by the authors, too.

- Green Futures