A rooftop garden of a Japanese museum. The cramped¹, concrete jungle that is Tokyo, one of the world's most densely² populated cities, has little space for parks. But things are starting to look up.

The cramped, concrete jungle that is Tokyo, one of the world's most densely populated cities, has little space for parks. But things are starting to look up.

In an attempt to add a little greenery to the concrete, many city roofs have been converted into gardens.

Rooftop planting has been on the rise since the city government, eight years ago, made it mandatory³ for new commercial buildings to cover at least 20 percent of available space with greenery.

"You see buildings and buildings all around Tokyo. Tokyo obviously needs more greenery as a city, and rooftop greening maybe one way to do it," said Atsuro Tarutoko, manager of the Hearton Hotel which was built three years ago with a $100,000 rooftop garden.

As well as the soothing⁴ aesthetics⁵, experts say the green roofs also provide environmental benefits as the gardens cut indoor temperatures, reducing air-conditioning costs.

"I believe part of our job is to try to merge⁶ some quality space into the city's landscape and allow local residents to feel that quality," said Aya Mugita, a construction project developer at a recent green technology expo in Tokyo.

Some information technology companies are already cashing in on the rooftop greenery business.

"We provide software that simulates the amount of carbon dioxide that can be absorbed by a garden based on the types and volumes of trees to be planted there," said Yutaka Tanaka of Tokyo-based software maker⁷ Ecol System.

But experts say converting the urban jungle that is Tokyo into a green refuge will take a few decades.

东京被称为拥挤的“钢筋水泥丛林”，也是世界上人口密度最大的城市之一，在这里几乎没有空间来修建公园，但如今情况却有所改观。

为了给钢筋水泥丛林增添一抹绿意，东京市内的很多屋顶已被改造成花园。

东京市政府于八年前强制推行屋顶绿化，规定新建商业建筑可利用空间的绿化率最少要达到20%。在这之后，东京屋顶绿化率逐步提高。

哈尔顿酒店经理Atsuro Tarutoko 说：“你在东京满眼望去，见到的除了楼房还是楼房。作为一个城市，东京当然需要更多绿意，而屋顶绿化也许正是一条可行之道。” 哈尔顿酒店修建于三年前，屋顶花园造价达十万美元。

屋顶花园不但美观，专家认为它还能降低室内温度，减少空调成本，从而保护环境。

建筑开发商Aya Mugita在东京最近举办的绿色技术博览会上说：“我认为我们的任务之一就是把一些优质空间融入到城市景观中，并让当地居民感受到这种品质。”

一些信息技术公司已经开始关注屋顶花园可能带来的商机。

东京软件制造商生态系统公司的Yutaka Tanaka说：“我们提供的软件可以根据所种植树木的种类和数量计算屋顶花园所吸收的二氧化碳排放量。”

但专家认为，东京这个城市从林要想转变为绿色港湾需要几十年时间。

Vocabulary:

 cramped: confined or severely limited in space（拥挤的，狭促的）

 cash in on: 靠……赚钱，乘机利用