Now, it's covered in buildings.

現在，它被建築覆蓋著。

Phoenix, along with Las Vegas, is experiencing a stretch of triple-digit temperatures made worse by a heat dome.

鳳凰城和拉斯維加斯正經歷連續數天的三位數高溫，而高溫穹頂使情況變得更糟。（譯註：此部影片溫度皆是指華氏氣溫）

- Record-level temperatures... - ... shows no signs of letting up.

- 創紀錄的氣溫⋯⋯ - ⋯⋯沒有任何減緩的跡象。

Unrelenting grip on the country.

無情地影響著國家。

A lot of our cities have got gotten... gotten bigger in the last 20 years, especially in the southwest.

在過去的 20 年裡，我們很多城市都變得越來越大，尤其是在西南部。

Here's what happens when heat domes form above cities and how urban growth can make that heat even more deadly.

以下是在城市上空形成熱穹頂時的情況，以及城市發展如何使熱能更加致命。

In Phoenix, over 20 days in July have been at or above 110 degrees.

在鳳凰城，7 月份有 20 多天氣溫達到或超過 110 度。

And space technology company Maxar, which has been tracking the weather, predicts the city will hit at least 30 by the end of the month.

而一直在跟蹤天氣變化的太空技術公司 Maxar 預測到本月底，該市將至少出現 30 次這種高溫。

In Las Vegas, 16 days are predicted to hit that high.

在拉斯維加斯，預計將有 16 天達到這一最高值。

That heat is driven, in part, by urban development.

造成這種熱浪的部分原因是城市發展。

Imagine a city as an island with pavement, roads, surfaces, glass, and steel buildings, all of these surfaces reflect sunlight and that heat energy from the sun back into the air around.

把城市想象成一個小島，上面有人行道、道路、路面、玻璃和鋼結構建築，所有這些表面都會反射陽光以及太陽熱能，使其迴流到周遭空氣中。

These highly-developed areas can see midday temperatures that are 15 to 20 degrees warmer than surrounding vegetated areas.

這些高度發達地區中午的溫度會比周圍植被茂盛的地區高出 15 到 20 度。

We can see how these heat islands formed by looking back at Phoenix⏤here it is 23 years ago.

我們可以回顧一下 23 年前的鳳凰城，看看這些熱島是如何形成的。

But after two decades of urban growth, the city has ballooned.

但經過 20 年的城市發展，這座城市膨脹了。

Back in 2000, Las Vegas looked like this.

2000 年時，拉斯維加斯是這個樣貌。

And, now, its city limits have expanded.

現在其城市範圍已經擴大。

That expansion paralleled their economic growth, but more infrastructure turned up the heat.

這個擴張與其經濟成長並進，但更多的基礎設施也在不斷增溫。

These are all places where heat gets trapped, right?

這些都是熱量滯留的地方，對吧？

So, in many of these cities, there's not a lot of breezes, there's not a lot of shade or trees.

所以說，在許多這樣的城市裡，沒有太多的微風、沒有太多的樹蔭或樹木。

And, so, as a result, heat can build up in these urban corridors.

因此，熱量會在這些城市走廊中積聚。

It's sometimes hard to grow trees in the west, especially in very arid places, and the native trees that grow there may not be great at providing shade.

在西部，特別是在非常乾旱的地方，有時很難種植樹木，而且當地生長的樹木可能並不適合遮蔭。

So, you have a lot of areas that get a lot... a lot of sun.

所以說，有很多地方都獲得很充足的陽光。

The other important thing about plants and trees and vegetation and even grass is they cycle moisture from the ground into the air and help, just a little bit, keep things cooler.

花草樹木、植被、甚至草地的另一個重要作用是，它們能將地面的溼氣循環到空氣中，並能在一定程度上保持涼爽。

That's driven temps in Phoenix and Las Vegas even higher and drove the creation of these heat islands.

那促使鳳凰城和拉斯維加斯的氣溫更高，推動了這些熱島的形成。

But that's not the only thing fueling the hot weather.

但這並不是造成天氣炎熱的唯一原因。

When you have a heat dome on top of this, it really intensifies the temperatures for everyone living in this city.

當你在這之上加一個熱穹頂時，它還讓生活在這座城市中的每個人都感到氣溫攀升。

These domes are a natural weather phenomenon, and for most of July, one has been covering the southwest.

這些圓頂是一種自然天氣現象，在 7 月期間，有一個一直覆蓋著西南部地區。

A heat dome is a large ridge of high pressure high in the atmosphere that basically traps a lot of hot air underneath it, and it can last for a long time.

熱穹是大氣層高處的一個大型高壓脊，它基本上會將大量熱空氣困在下面，而且會持續很長時間。

Over time, the heat dome is basically reinforcing itself in the sense that any moisture on the ground or in the soil that may come up into the atmosphere that, perhaps, could cause some rain or rainstorms in the afternoon,

隨著時間的推移，地面或土壤中可能上升到大氣中、可能在下午引起一些降雨或暴雨的任何溼氣，

that's going away; the soils are drying out, the land is drying out.

這些溼氣都正在消失，土壤在乾涸、土地在乾涸。

And, so, this hot air is making things worse and worse.

因此，這些熱氣讓情勢變得越來越糟。

The combination of a heat dome on top of a heat island means that being outside can be even more dangerous.

熱島之上再加上一個熱穹頂，這意味著在室外活動可能會更加危險。

Burn centers have reported injuries to people who touch hot door handles and walk barefoot on scorched pavement.

據燒傷中心報告，有人因觸摸滾燙的門把手或赤腳走在燒焦的路面上而受傷。

These are hot places, right?

這些地方很熱，對吧？

And, so, there's often this feeling of, "Well, it's always been hot here; we're used to it, we can deal with it."

所以人們經常會有這樣的感覺：「嗯，這裡一直都很熱。我們已經習慣了，我們可以應付。 」

But I think that masks some of the really significant risks that are faced by people experiencing homelessness, by people who are elderly, people who work outside,

但我認為，這掩蓋了無家可歸者、年長者、室外工作者所面臨的嚴重風險，

many of these different groups that are... that are exposed and vulnerable.

許多不同的群體都處於暴露和脆弱狀態。

In cities already experiencing triple-digit temperatures, the National Oceanic and Atmospheric Administration is preparing officials for increasing heat events.

在已經經歷三位數氣溫的城市中，美國國家海洋和大氣管理局正在讓官員們做好應對日益增多高溫事件的準備。

Everybody is very concerned about... about the future, that with warming and with climate change, we expect more of these events to happen, and when these events happen, they're... they're more intense.

每個人都非常關注未來，隨著氣候變暖和氣候變化，我們預計會有更多的此類事件發生，而當這些事件發生時，它們會更加劇烈。

And scientists say the heat is here to stay.

科學家們說，高溫將持續下去。

As architects, planners, and engineers look to the future,

建築師、規劃師和工程師都在展望未來，

they have to take into account the effects of climate change over time, temperatures that are rising, storms and other things that are happening as well.

他們必須考慮到氣候變化隨著時間推移而產生的影響、氣溫不斷升高的風暴以及正在發生的其它事情。

So, they're taking these things into account with new kinds of technologies, green roofs that can absorb and cool buildings,

所以他們將這些因素納入考慮範圍，採用新型技術、能夠吸收和冷卻建築物的綠色屋頂，

and, also, just in the design and shape of buildings that can provide more shade and maybe just have a little bit of resiliency toward a warming climate that we're all facing in the future.

以及建築物的設計和形狀，以提供更多的遮蔭，或許對我們未來都將面臨的氣候變暖有一點適應能力。