SHANGHAI - On the eastern tip of Chongming, the world's largest alluvial island in the mouth of the Yangtze River, birdwatchers wait patiently to glimpse an occasional crane or plover rising from the wetlands' reeds.
A few kilometres to the southwest, in an area of fishponds, marshes and farmland, developers are plotting out a city for up to 400,000 people that they hope will be a model of ecological harmony, powered entirely by renewable energy.
Shanghai's Dongtan Eco-city has a lofty ambition: To become the world's first carbon-neutral city.
But the project has been marred by delays and faces rising doubts over whether it will be a model for China's rapid urbanisation, or just a posh community for wealthy commuters eager to flee the smog and traffic of Shanghai.
"'Zero-emission' city is pure commercial hype," said Dai Xingyi, a professor at the department of environmental science and engineering at Shanghai's Fudan University.
"You can't expect some technology to both offer you a luxurious and comfortable life, and save energy at the same time. That's just a dream," he said.
Ten wind turbines already stand at the boundaries of the city, which will run on energy from sources including wind, solar power and biogas extracted from municipal waste.
"The idea is that China is moving from an industrial age to an ecological age," said Roger Wood, an associate director of Arup, a consulting firm headquartered in London that was selected to design the Dongtan project.
Arup also worked on some iconic venues for the Beijing Olympics, including the National Stadium, popularly known as the "Bird's Nest", where the opening ceremony and track and field events will be held.
The Price of Zero Emissions
Some dismiss the eco-city plan as too costly to be feasible.
"True 'zero-emissions' comes with a big price tag. I doubt anyone would be willing to pay for it," said Fudan University's Dai.
Generating electricity from wind would be at least twice more expensive than using coal. Electricity from solar power could be ten times more expensive.
Arup has declined to disclose the cost of the eco-city project, but an official at its partner, state-owned Shanghai Industrial Investment Corporation (SIIC), said the construction costs could be at least 30 or 40 percent more than for a typical property development of the same size.
Those costs would be offset in the long term, Arup's Wood argued, when the city became self-sufficient in energy.
Environmental friendliness must be practical, he said, not just an image to splash over a "business-as-usual" development.
"We don't want 'green-wash'. It's got to be real."
Construction of the first phase of the eco-city has been postponed to the beginning of 2009 from 2006, while the projected population for that phase was reduced to 5,000 and the primary focus narrowed to building an environment-related research institute.
The project's supporters applaud it for combining existing energy-saving technologies.
"Dongtan is exploring a new way of urbanisation," said Zheng Shiling, a professor at the architecture department of Tongji University in Shanghai. "It would not be realistic if we continued to build cities the way we've been doing."
New Model
Hailed as a new model of urbanisation, Dongtan Eco-city would occupy 30 square kilometres -- half the size of Manhattan -- and house 400,000 residents by the time it is completed in 2050.
Arup envisions farmers and fishermen living outside the city, providing fresh produce and seafood to city dwellers.
But at the fisherman's wharf, where dozens of fishing boats were at anchor on a windy afternoon, fishermen and shopkeepers were not enthused about the project.
"We won't move into that city, because we are not educated and we would be useless," said 45-year-old Pan Meiqin, who runs a small grocery store with her husband.
Today a trip to Chongming takes at least 40 minutes by ferry from the outskirts of Shanghai, and storms can halt traffic entirely. A tunnel and bridge, scheduled for completion in 2009, will make trips to the island faster and more reliable.
Some experts predicted the improved access would turn Dongtan into a community for wealthy commuters, drawn to its marinas and its clean air and water.
"It will therefore be characterised by high levels of personal consumption and large per capita eco-footprints," William Rees, a professor at the University of British Columbia, wrote in an e-mail reply to queries on the project.
Rees is a pioneer in ecological footprint analysis, which estimates how much land and water area a human population requires to produce the resources it needs.
Arup's goal is to ensure the city's ecological footprint is 40 percent less than a typical development model.
The eco-city plan took on a high international profile after Britain's then-Prime Minister Tony Blair graced the signing ceremony for the Dongtan planning and development contract between SIIC and Arup at Number 10 Downing Street in 2005. Blair's successor Gordon Brown has hailed the project as a successful example of cooperation between Britain and China.
While debate rages over the environmental value of the project, some experts see such eco-cities as the future of urban development.
"Accepting that urbanisation in the developing world is inevitable, it is probably better to build nominal eco-cities than standard low-efficiency buildings and urban infrastructure," said Rees.
