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  • Welcome to

  • This time, I'm going to talk about future cities.

  • A modern city can be thought of as gigantic creature

  • that depends on resources fed to it from around the planet.

  • However, in the future,

  • such global supplies cannot be guaranteed.

  • Cities have evolved into sophisticated cybernetic machines

  • for keeping civilization alive.

  • In some aspects, cities are therefore humanity's greatest achievement.

  • Nevertheless, most cities would decend into anarchy

  • in only 48 hours without a constant supply

  • or food, energy and clean water.

  • The Industrial Revolution saw a mass migration

  • of people from the country side.

  • Those who remained on the land

  • then had to develop increasingly intensive farming methods

  • to meet the food requirements of urban dwellers

  • who could not feed themselves.

  • Canals, railways and roads allowed the first industrial cities

  • to be supplied with their daily nutrition.

  • However, this resulted in a food chain

  • dependant not just on the complex transport infrastruture,

  • but also fuel and modern fertilizers.

  • As a consequence, today, every calorie we eat

  • also requires the consumption of 10 calories of oil.

  • And within a few decades at best,

  • this addiction of the modern city to petroleum

  • will no longer be sustainable.

  • There are, however, possibilities that the farm

  • may migrate from the countryside.

  • So called 'vertical farming' could involve multi-tiered city farms

  • in future glass skyscrapers or pyramids.

  • Such stacks of artificial fields would allow city dwellers

  • to harvest crops all year round in areas without available land.

  • They would also significantly reduce

  • the energy required for food transportation,

  • would lower crop loss associated with shipping and storage,

  • could recycle their own water,

  • and, within their sealed environments,

  • may even use fewer pesticides.

  • One vertical farm could potentially feed 50,000 people.

  • However, even before the construction of such massive projects,

  • laws could be passed requiring all new buildings in large cities

  • to have at least some space dedicated to food production.

  • For example, new apartment blocks could be required to include

  • hydroponical lodgements on the roof.

  • In addition to food, all cities currenly require significant natural resources

  • to meet their raw energy needs.

  • However, alternative technologies,

  • including solar cells, rooftop wind turbines,

  • ground source heat pumps,

  • and methane power plants fuelled from domestic rubbish

  • could see future cities becoming at least partly energy sufficient.

  • Micro power generation may even extend to piezo-electric paving slabs

  • to generate electricity from our footsteps,

  • as well as hydraulic plates in road surfaces

  • that would generate power as vehicles drive over them.

  • In addition to producing at least some of their own food and power,

  • future cities will also have to use fresh water far more efficiently.

  • In part this is because treating and transporting fresh water is energy intensive.

  • However, half of the world's population now live in countries

  • where the water table is falling.

  • Future cities will therefore need to capture

  • and recycle water whenever this is possible.

  • Future food, energy and water supplies are at best uncertain.

  • The global population of city dwellers also continues to increase.

  • Future cities will there have to become leaner and more self-sufficient.

  • For more information, please see

  • But now that's it for another video.

  • And remember, the future is in your hands.

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B1 中級

未來城市 (Future Cities)

  • 97 8
    richardwang 發佈於 2021 年 01 月 14 日