What will the cities of the future look like?
For many, images of space cars whizzing along roads, and robots greeting us with mechanical smiles come to mind. But for others, such farfetched notions are the stuff of dreams (or nightmares) as they ask the question: Will our cities even have a future?
At an event at Imperial College in London this week, a panel of scientists, architects and engineers discussed their visions for how our cities can best adapt and thrive in response to serious threats such as climate change, population growth and overburdened infrastructure.
Cities will come under massive energy stress as their inhabitants continue to swell, said Stephen Hall, research fellow with the School of Earth and Environment at Leeds University.
"Cities have lost control of energy systems," he said. As demand for energy grows, cities must not only meet that but also manage the rising greenhouse gas emissions and air pollution that come with it, he added.
City planners are often torn between grid-based, top-down power systems and more decentralised, smart energy systems. "Which pathway do you take?" asked Hall.
Most discussions around the shift to renewable energy depict traditional power stations as the "bad boy of the past", and presume a clean, green break can be made by adopting renewable energy sources and "retrofitting" existing structures, he said.
But Hall argued it’s not a clear-cut choice, urging more sophisticated thinking that draws on the different types of resources available in each location.
In many cases, cities around the world will continue to rely on grid systems powered by fossil fuels for some time, but intertwined with that, they should be developing greener opportunities, he added.
For example the EU Energy Union allows countries across Europe to share and swap power across an inter-connected ‘supergrid’, where wind turbines in Doncaster could work in harmony with solar panels in Alicante to ensure an even flow of renewable power across the continent.
"Cities need to recognise that the systems of tomorrow are not the systems of today," said Hall.
IS GREEN LIVING HEALTHIER?
Another key challenge for many cities is preserving green spaces as growing populations require more housing, schools, shops and hospitals, and built-up areas encroach on parks and other public land.
Scientists are currently researching whether green spaces have tangible benefits for the health of urban populations.
There are around 3,000 parks in London and 3 million private gardens, said Charlie Roscoe, a doctoral student at Imperial College London’s Centre for Environment and Health.
Studies have used satellite imagery to map out vegetation to analyse the impact of green spaces on neighbourhoods. Perhaps unsurprisingly, they found that fewer people under retirement age died the more green space they had in their neighbourhood, said Roscoe.
If you live close to a park, you may be more likely to exercise, enjoy fresh air and have fewer psychological health problems, she said.
But when studies analysed whether this trend could be seen on a broader scale, examining 50 British town and cities with more than 100,000 residents, they found no association between green spaces and mortality rates. Research in the United States has produced similar findings, said Roscoe.
"It's to do with your neighbourhood - it's to do with what's close to you, it's to do with what you experience day-to-day," said Roscoe.
Efforts are underway to work out how to scale up the positive effects of green spaces across cities so they are not just confined to neighbourhoods with green pockets.
Creating more parks and open spaces today could help inhabitants of future cities suffer less from obesity and diabetes, and enjoy better cardio-vascular health, said Roscoe.
Some developed cities are already taking innovative steps, she noted, including Barcelona which is setting up “superblocks” to boost pedestrianisation and public space, and London where inhabitants are being asked to cultivate urban farms.
With the world’s cities expected to be home to more than two-thirds of the global population by 2050, keeping their residents healthy can go hand-in-hand with protecting the environment and enabling urban economies to prosper, experts agreed.
"It's not too late for us," said Roscoe.