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Despite its green credentials as a “zero emission, net carbon-positive, sustainable” development, 68 out of 69 nearby residents have objected to the scheme. “It is not at all in keeping with the area and dwarfs nearby properties,” said one. “The design is unattractive. Covering it in greenery doesn’t fool anyone.” But 5,700 miles away in Liuzhou in southern China attitudes could not be more different. The authorities there have given the go-ahead to not one but 70 buildings cascading with foliage. In short, the construction of a revolutionary “forest city” whose one million plants and 40,000 trees will “eat” its own toxic smog.

STEFANOBOERI Liuzhou Forest City, designed by Stefano Boeri, will include 70 buildings with cascading foliage

LUMIEREUK 68 out of 69 local residents in Hemel Hempstead have objected to a similar scheme

I really think that bringing forests into the city is a way to reduce climate change Stefano Boeri

In a country where more than a million people a year die from the effects of air pollution, environmentally-friendly architecture is all the rage these days. And the Liuzhou Municipality Urban Planning Bureau has signed up Italian architect Stefano Boeri, the father of the forest city movement, to build a self-contained community for up to 30,000 people. He is the go-to man for such projects these days thanks to the success of his “vertical forests”, two residential towers in Milan covered in the equivalent of five acres of plant life. Completed in 2014, they remove up to 17.5 tons of soot from the air each year, according to Boeri, and a year later one of them was named Best Tall Building Worldwide. The Liuzhou project is a much more ambitious undertaking, however. Its homes, hospitals, hotels, schools and offices will be built on a 340-acre site in what Boeri calls the first attempt to create an “urban environment that is really trying to find a balance with nature”.

Its 100 species of plant life are expected to absorb almost 10,000 tons of carbon dioxide and 57 tons of pollutants per year, while at the same time producing 900 tons of life-giving oxygen. What’s more, the greenery will decrease the ambient air temperature and provide a new habitat for displaced wildlife. Meanwhile, roof-mounted solar panels will generate renewable energy to power the buildings, while geothermal energy – generated by exploiting the heat trapped in the Earth’s crust – will power air-conditioning. Although the architects haven’t published the cost of the forest city, the Milan towers cost only five per cent more than traditional skyscrapers. China’s enthusiasm for projects of this sort is driven by a belated recognition that it is paying an increasingly heavy price for its race to achieve economic growth at all costs over the past three decades.

GETTY Stefano Boeri poses outside 'Bosco Verticale' (Vertical Forest) in the Porta Nuova area in Milan

As the country underwent its equivalent of Europe’s 19th-century Industrial Revolution, millions of people a year forsook their jobs on the land for a new life in the city. In 2011, China’s urban population outnumbered its rural population for the first time: 690 million versus 656 million. As a result there are now more than 160 cities in China with over one million residents. And all too often they are blanketed in smog. Things got so bad in the Chinese capital Beijing one day in December 2016 that the authorities declared a five-day pollution “red alert”. Schools were shut, thousands of vehicles were ordered off the roads and residents were told to stay indoors.

City officials were also reported to have “penalised” 388 people for lighting barbecues and fires outdoors. But Dong Liansai, a Beijing-based climate and energy campaigner for environmental group Greenpeace, said coal-fired power stations, not barbecues, were to blame for the unusually severe bout of pollution. “Coal is the number one source,” said Dong, warning that the smog contained tiny airborne particulates known as PM2.5 which were linked to numerous “adverse health effects” including lung cancer, asthma and heart disease. In a bid to reduce its reliance on coal, the Chinese government has set up a series of large-scale wind farms. But it is investing in cure as well as prevention. A year ago Boeri, who set up a branch of his architectural practice in Shanghai in 2014, unveiled plans for two neighbouring towers coated with 1,100 trees – in a range of 23 species – and more than 2,500 shrubs in the eastern Chinese city of Nanjing.

The taller tower – 660ft high, almost four times the height of Nelson’s Column – will house 28 floors of offices, a museum, a green architecture school and a private club on the top floor. While the second tower, 350ft high, will host a Hyatt hotel with 247 rooms and a rooftop swimming pool, plus a range of retailers, a food market, restaurants, conference hall and exhibition spaces at ground level. As well as contributing to the regeneration of local biodiversity, the towers’ plant life will absorb 25 tons of carbon dioxide each year and produce about 60kg of oxygen every day. Having finalised the plans for Nanjing, it wasn’t long before Boeri began to think bigger. “We started to imagine if it was possible to create an urban environment created from many of these vertical forests,” he said.

“We’ve seen what’s happening [in terms of pollution] in Beijing and Shanghai, but at the same time, China has to create the cities to accommodate the population.” His visionary solution to this problem is to build a series of sustainable mini cities that could be a blueprint for the future of urban China. The first such settlement will be the one at Liuzhou, a mid-sized Chinese city of about 1.5 million residents in the mountainous southern province of Guangxi, with a second project planned for Shijiazhuang, an industrial hub in northern China that is consistently among the country’s ten most polluted cities. Boeri reckons Chinese officials are finally coming to terms with the need to embrace a new, more sustainable model of urban planning that involves not “huge megalopolises” but settlements of 100,000 people or fewer that were entirely constructed of “green architecture”. “What they have done until now is simply to continue to add new peripheral environments to their cities,” he said.

Air pollution across the world Tue, May 22, 2018 Take a look through these stunning drone images, highlighting the effects of pollution on planet earth but also the opportunities to tackle this scary problem. Play slideshow Mark Baker 1 of 11 The tanks and stacks of Fawley Refinery in the New Forest