Let's Get 7 in IELTS

 Agriculture is broken. Traditional techniques use too much energy and produce too little food for our growing planet. One fix: skyscrapers filled with robotically tended hydroponic crops and lab-grown meat

By 2025, the world’s population will swell from 6.6 billion to 8 billion people. Climate simulations predict sustained drought for the American Midwest and giant swathes of farmland in Africa and Asia. Is mathematician Thomas Malthus’s 200-year-old prediction, that human growth will one day outpace agriculture, finally coming to pass? Advances in farming technology have kept us fed so far, but the planet’s resources are tapped.

The choice is clear—rethink how we grow food, or starve. Environmental scientist Dickson Despommier of Columbia University and other scientists propose a radical solution: Transplant farms into city skyscrapers. These towers would use soil-free hydroponic farming to slash demand for energy (they’ll be powered by a process that converts sewage into electricity) while producing more food. Farming skyward would also free up farmland for trees, which would help remove carbon dioxide from the atmosphere. Even better, vertical farms would grow food near where it would be eaten, thus cutting not only the cost but the emissions of transportation. If you include emissions from the oil burned to cultivate and ship crops and livestock in addition to, yes, methane from farm-animal flatulence, agriculture churns out nearly 14 percent of the world’s greenhouse-gas emissions.

You can’t buy vertically grown groceries just yet. Most urban farming efforts have been small-scale experiments run in neighborhood parks. Despommier’s vision is bigger: a $200-million, 30-story tower covering an entire city block, stuffed with enough fruit, vegetables and chickens to feed 50,000 people. “With waste in and food out, a vertical farm would be like a perpetual-motion machine that feeds a lot of people,” he says. Most of the technology already exists, he adds, and with some refining, the project could be up and running quickly if granted 0.25 percent of the subsidies paid to American farmers in the past decade—a piddling $500 million.

Despommier is advising investors in Abu Dhabi and South Korea who are considering vertical farms for new eco-cities. Seattle and Las Vegas are investigating similar, smaller concepts. Turn the page to explore the farm of the future, inspired by cutting-edge research from agricultural companies and scientists. With any luck, it will help repel the Malthusian catastrophe for another 200 years.

sustained
a.
1. 持久的;持續的
drought
n.[C][U]
1. 乾旱
2. 旱災,長期乾旱
3. (長期的)缺乏,不足
swathe
n.
1. =swath
vt.
1. 包紮;包裹
2. 包圍
hydroponic
a.
1. 水栽的
methane
n.
1. 【化】甲烷,沼氣
flatulence
n.
1. 【醫】胃腸氣脹
2. 浮誇;自負

英漢雙向醫學詞典
（腸胃）氣脹
churn out
1. 大量生產
She churns out about ten new books every year.
她每年出版大約十本書。
perpetual
a.
1. 永久的;長期的
They hoped to live in perpetual happiness.
他們希望生活在永久幸福之中。
2. 【口】無休止的;連續不斷的
I'm tired of your perpetual nagging.
我對你無休止的嘮叨厭煩了。
3. 無限期的;終身的
He was perpetual president of the country.
他是該國的終身總統。
4. 四季開花的
That is a hybrid perpetual rose.
那是一株雜種的四季開花的薔薇。
n.
1. 【植】四季開花的薔薇;多年生植物
eco-cities
n.
1. 表示"生態(的)","環境(的)"城市
cutting-edge
ph.
1. 最前線;尖端
California is on the cutting edge of trends that spread nationwide.
加州走在全國流行的尖端。
2. 最重要的位置