This is the tale of two ancient cities and the trees that determined their destinies.

這是有關兩座古老城市，與決定他們命運的樹林的故事。

In 3,000 BC Uruk was more densely populated than modern day New York City. [75.000 people in 6 km2]

西元前 3,000 年，烏魯克的人口密度比現在的紐約還高。[六平方公里中有七萬五千人]

This crowded capital had to continually expand their irrigation system to feed its growing population.

這擁擠的首都必須不斷擴展灌溉系統，才能養活不斷成長的人口。

2,500 years later in Sri Lanka, the city of Anuradhapura had a similar problem.

2,500 年後，斯里蘭卡的城市阿努拉德普勒也出現了相似的問題。

They were also growing constantly, and like Uruk, their city relied heavily on an elaborate irrigation system.

該城市的人口也不斷成長，如同烏魯克，他們也非常仰賴完善的灌溉系統。

As Uruk grew, its farmers began chopping down trees to make space for more crops.

隨著烏魯克的擴展，當地農夫開始伐樹，以便種植更多作物。

In Anuradhapura, however, trees were sacred.

然而，在阿努拉德普勒，樹木是神聖的。

Their city housed an offshoot of the Bodhi tree under which Buddha himself was said to have attained enlightenment.

因為該城市中有棵菩提樹，據說是佛陀悟道之處。

Religious reverence slowed farmer's axes and even led the city to plant additional trees in urban parks.

對宗教的敬畏，減緩當地農民的砍伐，該城市甚至在公園中種下更多樹木。

Initially, Uruk's expansion worked well.

起初，烏魯克的擴展非常順利。

But without trees to filter their water supply, Uruk's irrigation system became contaminated.

但少了樹木來過濾供水系統，烏魯克的灌溉系統受到了污染。

Evaporating water left mineral deposits, which rendered the soil too salty for agriculture.

水蒸發後留下了礦物質，使土壤鹽度變得太高，無法植種農作物。

Conversely, Anuradhapura's irrigation system was designed to work in concert with the surrounding forest.

相反地，阿努拉德普勒的灌溉系統是設計來與森林共存的。

Their city eventually grew to more than twice Uruk's population, and today, Anuradhapura still cares for a tree planted over 2,000 years ago.

最後此城市的人口成長為烏魯克的兩倍，而時至今日，阿努拉德普勒仍在照料一棵至少 2,000 歲的神木。

We may think of nature as being unconnected to our urban spaces, but trees have always been an essential part of successful cities.

我們或許會認為大自然與都市空間沒有關聯，但樹木向來都是成功都市的重要部分。

Trees act like a natural sponge, absorbing storm water runoff before releasing it back into the atmosphere.

樹木就像天然的海綿，可以吸收暴風雨帶來的雨水，之後再釋放回大氣之中。

The webs of their roots protect against mudslides while allowing soil to retain water and filter out toxins.

樹根所形成的網絡可以預防土石流，也能讓土壤保持水份並過濾有毒物質。

Roots help prevent floods, while reducing the need for storm drains and water treatment plants.

樹根可以預防洪水，同時減少當暴風雨來臨時，排水設備與污水處理廠的需求。

Their porous leaves purify the air by trapping carbon and other pollutants, making them essential in the fight against climate change.

透氣的樹葉能捕捉碳分子及其他污染物，以此來淨化空氣，是對抗氣候變遷的重要角色。

Humanity has been uncovering these arboreal benefits for centuries.

數世紀以來，人類不斷發現樹木的益處。

But trees aren't just crucial to the health of a city's infrastructure; they play a vital role in the health of its citizens as well.

但樹木可不僅只會影響一個城市的基礎設施，它們對都市居民的健康也有重要影響。

In the 1870s, Manhattan had few trees outside the island's parks.

在 1870 年代時，曼哈頓島上除了公園，很少有樹木。

Without trees to provide shade, buildings absorbed up to nine times more solar radiation during deadly summer heat waves.

沒有了樹木來提供遮蔭，在致命夏日熱浪時期，建築物吸收了比一般高出九倍的太陽輻射。

Combined with the period's poor sanitation standards, the oppressive heat made the city a breeding ground for bacteria like cholera.

加上當時的衛生標準低落，致命高溫讓該城市成為霍亂等細菌的溫床。

In modern day Hong Kong, tall skyscrapers and underground infrastructure make it difficult for trees to grow.

在現代的香港，高樓大廈與地下基礎設施讓樹木難以生長。

This contributes to the city's dangerously poor air quality, which can cause bronchitis and diminished lung function.

這導致了香港的空氣品質低落，甚至可能造成支氣管炎或肺縮小。

Trees affect our mental health as well.

樹木也會影響我們的心理健康。

Research indicates that the presence of green foliage increases attention spans and decreases stress levels.

研究指出，綠色樹葉可以延長注意力，並減少壓力。

It's even been shown that hospital patients with views of brick walls recover more slowly than those with views of trees.

甚至有跡象顯示，在醫院內，若患者看到的景色是磚牆，會比景色為樹木的患者更慢康復。

Fortunately, many cities are full of views like this—and that's no accident.

幸運的是，許多城市都有這樣的景色——且這不是巧合。

As early as the 18th century, city planners began to embrace the importance of urban trees.

早自 18 世紀起，都市規劃者便開始看重都市樹木的重要性。

In 1733, Colonel James Oglethorpe planned the city of Savannah, Georgia to ensure that no neighborhood was more than a two-minute walk from a park.

1733 年時，James Oglethorpe 上校重新規劃了喬治亞州的薩凡納，確保每個社區在步行兩分鐘內都有公園。

After World War II, Copenhagen directed all new development along five arteries—each sandwiched between a park.

二次世界大戰後，哥本哈根沿著五條幹道進行開發，每條幹道都被公園圍繞著。

This layout increased the city's resilience to pollution and natural disasters.

這個方式，增加了該城市對污染及天災的恢復力。

And urban trees don't just benefit people.

都市中的樹木，不只有對人類有益。

Portland's Forest Park preserves the region's natural biodiversity, making the city home to various local plants, 112 bird species, and 62 species of mammals.

波特蘭的森林公園保留了該地的自然生物多樣性，使該城市成為許多當地植物、112 種鳥類與 62 種哺乳動物的家園。

No city is more committed to trees than Singapore.

而最重視樹木的國家，非新加破莫屬了。

Since 1967, Singapore's government has planted over 1.2 million trees, including those within 50-meter tall vertical gardens called supertrees.

自 1967 年來，新加坡政府已經種下超過 120 萬顆樹，包含那些種在 50 公尺高的垂直花園中的超級樹木。

These structures sustain themselves and nearby conservatories with solar energy and collected rainwater.

這些建物能自給自足，還能將太陽能與收集的雨水供應給附近的溫室。

Trees and vegetation currently cover over 50% of Singapore's landmass, reducing the need for air conditioning and encouraging low-pollution transportation.

新加坡超過 50% 的地面都被植披與樹木覆蓋，減少了對空調的需求，也鼓勵了低污染的交通。

By 2050, it's estimated that over 65 percent of the world will be living in cities.

到了 2050 年，估計全世界有超過 65% 的人都會住在都市中。

City planners can lay an eco-friendly foundation, but it's up to the people who live in these urban forests to make them homes for more than humans.

城市規劃者可以設立環境友善的基礎，但是能不能容納更多人類以外的生物，取決於這些住在都市叢林中的人們。

The time to get involved with the climate movement is now.

現在就是參與氣候運動的時機。

Don't know where to start?

不知道從哪開始嗎？

We've partnered with the U.N. to create a 30-day challenge designed to teach you everything you need to know to become a part of the solution.

我們與聯合國一起創少了一個三十天的挑戰，旨在教你所有你需要知道的氣候運動相關事項。

Start the challenge with a friend or family member today.

今天就與一個朋友或家人開始挑戰吧！