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  • As you've probably noticed,

    譯者: Lilian Chiu 審譯者: Helen Chang

  • in recent years, a lot of western forests have burned

    你們可能已經注意到,

  • in large and destructive wildfires.

    近年來,有很多西部的森林

  • If you're like me --

    遭到毀滅性的大型野火摧殘。

  • this western landscape is actually why my family and I live here.

    如果你們和我一樣,

  • And as a scientist and a father,

    像這樣的西部風景,就是我和 我的家人會住在這裡的原因。

  • I've become deeply concerned about what we're leaving behind

    身為科學家和父親,

  • for our kids, and now my five grandkids.

    我非常關切我們會留下什麼給

  • In the US, an area that's larger than the state of Oregon has burned

    我們的孩子,和我現在的五個孫子。

  • in just the last 10 years,

    在美國,僅在過去十年間,

  • and tens of thousands of homes have been destroyed.

    被火燒毀的面積就比奧勒崗州還大,

  • Acres burned and homes destroyed have steadily increased

    數萬個家園因此被摧毀。

  • over the last three decades,

    過去三十年間,被燒毀的土地面積 和被摧毀的家園數目

  • and individual fires that are bigger than 100,000 acres --

    一直穩定在增加,

  • they're actually on the rise.

    而面積大於十萬英畝的個別火災數目

  • These are what we call "megafires."

    事實上是在增加的。

  • Megafires are the result of the way we've managed this western landscape

    我們稱這些大火為「超級大火」。

  • over the last 150 years

    超級大火發生的原因, 是我們過去 150 年來,

  • in a steadily warming climate.

    在穩定持續暖化的氣候下,

  • Much of the destruction that we are currently seeing

    經營這塊西部地景的方式。

  • could actually have been avoided.

    我們目前看到的破壞,

  • I've spent my entire career studying these western landscapes,

    其實大多數是本來可以避免的。

  • and the science is pretty clear:

    我的整個職涯都在 研究這些西部地景,

  • if we don't change a few of our fire-management habits,

    科學是非常明確的:

  • we're going to lose many more of our beloved forests.

    如果不改變我們 管理大火的一些習慣,

  • Some won't recover in our lifetime

    我們將會失去更多更多鍾愛的森林。

  • or my kids' lifetime.

    有些是在我們一生中, 甚至我們孩子的一生中,

  • It's time we confront some tough truths about wildfires,

    都無法復元的。

  • and come to understand that we need to learn to better live with them

    該是時候了,該來面對 關於野火的棘手真相了,

  • and change how they come to our forests,

    要了解,我們必須學習 和它們共處得更好一些,

  • our homes

    並改變它們如何來到我們的森林、

  • and our communities.

    我們的家園、

  • So why is this happening?

    我們的社區。

  • Well, that's what I want to talk to you about today.

    所以,為什麼會發生?

  • You see this forest?

    這就是今天我想和大家談的。

  • Isn't it beautiful?

    看到這座森林了嗎?

  • Well, the forests that we see today

    它很美,不是嗎?

  • look nothing like the forests of 100 or 150 years ago.

    我們現今看到的森林,

  • Thankfully, panoramic photos were taken in the 1930s

    一點也不像 100 或 150 年前的森林。

  • from thousands of western mountaintop lookouts,

    謝天謝地,1930 年代時,

  • and they show a fair approximation

    自西部山頂瞭望所 拍攝了數千個全景照片,

  • of the forest that we inherited.

    靠這些照片,我們可以大略呈現出

  • The best word to describe these forests of old is "patchy."

    我們所繼承的森林的樣貌。

  • The historical forest landscape was this constantly evolving patchwork

    要形容這些老森林, 最好的詞就是「拼湊成的」。

  • of open and closed canopy forests of all ages,

    歷史的森林地景, 是不斷演化的拼湊之作,

  • and there was so much evidence of fire.

    由各種年齡,稀疏與鬱閉的 冠層森林拼湊而成,

  • And most fires were pretty small by today's standards.

    有好多大火燒過的痕跡。

  • And it's important to understand that this landscape was open,

    用現今的標準來看, 大部份的火災規模都算很小。

  • with meadows and open canopy forests,

    重要的是要了解這是個稀疏的地景,

  • and it was the grasses of the meadows

    有草地,也有稀疏冠層森林;

  • and in the grassy understories of the open forest

    是草地上的草,

  • that many of the wildfires were carried.

    以及稀疏森林中長滿草的林下層,

  • There were other forces at work, too, shaping this historical patchwork:

    被許多野火燒了過去。

  • for example, topography, whether a place faces north or south

    還有其他的力量 形成這個歷史上的拼湊物,

  • or it's on a ridge top or in a valley bottom;

    比如:地形學,地形朝南或朝北,

  • elevation, how far up the mountain it is;

    是在山脊上或是在谷底;

  • and weather, whether a place gets a lot of snow and rain,

    海拔高度,在山上多高的地方;

  • sunlight and warmth.

    是否常常下雪或是下雨,

  • These things all worked together

    是否有陽光且溫暖。

  • to shape the way the forest grew.

    所有這些元素加在一起,

  • And the way the forest grew shaped the way fire behaved

    造成森林成長的方式。

  • on the landscape.

    而森林成長的方式,

  • There was crosstalk between the patterns and the processes.

    就會形成大火在地景上的行為方式。

  • You can see the new dry forest.

    在模式和過程之間互相干擾影響。

  • Trees were open grown and fairly far apart.

    如你所見,左側是新的乾燥森林。

  • Fires were frequent here, and when they occurred,

    樹木開放成長,且間距算是遠的。

  • they weren't that severe,

    大火常常在這裡發生,

  • while further up the mountain,

    發生時都不會太嚴重,

  • in the moist and the cold forests,

    再往山上一點,

  • trees were more densely grown and fires were less frequent,

    中間是潮濕且寒冷的森林,

  • but when they occurred, they were quite a bit more severe.

    樹木的密度比較高, 比較不常發生大火,

  • These different forest types, the environments that they grew in

    但一旦發生大火, 通常會比較嚴重一些。

  • and fire severity -- they all worked together

    不同類型的森林、它們的生長環境,

  • to shape this historical patchwork.

    以及大火的猛烈程度, 通通作用在一起,

  • And there was so much power

    形成了這個歷史的拼湊之作。

  • in this patchwork.

    在這個拼湊之作當中,

  • It provided a natural mechanism

    有著非常大的力量。

  • to resist the spread of future fires across the landscape.

    它提供了一個自然機制,

  • Once a patch of forest burned,

    來抵抗未來的大火, 不讓它們在地景上擴散。

  • it helped to prevent the flow of fire across the landscape.

    一旦森林其中一塊被燒掉,

  • A way to think about it is,

    它能協助防止大火延燒至地景各處。

  • the burned patches helped the rest of the forest

    可以把它看待成,

  • to be forest.

    森林中被燒毀的那些部份,

  • Let's add humans to the mix.

    能協助維持剩下的森林仍然是森林。

  • For 10,000 years, Native Americans lived on this landscape,

    讓我們混合考量人類的因素。

  • and they intentionally burned it -- a lot.

    美國原住民在這地景上住了一萬年,

  • They used fire to burn meadows and to thin certain forests

    他們常常會刻意放火,

  • so they could grow more food.

    用火燒草原,讓某些森林變得稀疏,

  • They used fire to increase graze

    來種更多的食物。

  • for the deer and the elk and the bison that they hunted.

    他們用火來增加牧草的量,

  • And most importantly, they figured out

    供獵獲的鹿、麋和野牛食用。

  • if they burned in the spring and the fall,

    最重要的是

  • they could avoid the out-of-control fires of summer.

    他們了解如果在春天和秋天放火,

  • European settlement -- it occurred much later, in the mid-1800s,

    就能避免夏天失控的大火。

  • and by the 1880s, livestock grazing was in high gear.

    很久之後,歐洲人 於十九世紀中期開始殖民,

  • I mean, if you think about it, the cattle and the sheep ate the grasses

    1880 年代到達家畜放牧的高點。

  • which had been the conveyer belt for the historical fires,

    我的意思是,試想牛和羊要吃草,

  • and this prevented once-frequent fires from thinning out trees

    這些草地曾是史上火災的輸送帶,

  • and burning up dead wood.

    使得以前頻繁的大火

  • Later came roads and railroads, and they acted as potent firebreaks,

    不再能夠稀疏樹木、燒光枯木。

  • interrupting further the flow of fire across this landscape.

    然後出現了道路和鐵路, 它們成了非常有效的防火道,

  • And then something happened which caused a sudden pivot

    進一步阻斷大火延燒至地景各處。

  • in our society.

    接下來發生的事使社會突然轉變。

  • In 1910, we had a huge wildfire.

    1910 年,有一場大野火,

  • It was the size of the state of Connecticut.

    大小和康乃迪克州一樣大。

  • We called it "the Big Burn."

    我們稱之為「大火燒(Big Burn)」。

  • It stretched from eastern Washington to western Montana,

    它的範圍從華盛頓州的東邊 一路延伸到蒙大拿州的西邊,

  • and it burned, in a few days, three million acres,

    幾天之內就燒毀了三百萬英畝的地,

  • devoured several towns, and it killed 87 people.

    吞滅了數個小鎮,

  • Most of them were firefighters.

    造成 87 人死亡,

  • Because of the Big Burn, wildfire became public enemy number one,

    大部份是消防員。

  • and this would shape the way that we would think about wildfire

    這次的大火燒使得野火 成了全民的頭號公敵,

  • in our society

    塑造我們社會在接下來百年間

  • for the next hundred years.

    對於野火的看法。

  • Thereafter, the Forest Service, just five years young at the time,

    其後,當時成立才五年的林務局

  • was tasked with the responsibility of putting out all wildfires

    被賦予重任,

  • on 193 million acres of public lands,

    要消滅公地上所有的野火,

  • and they took this responsibility

    多達 193 百萬英畝的面積。

  • very seriously.

    他們非常認真地看待這項責任,

  • They developed this unequaled ability to put fires out,

    發展出無與倫比的滅火能力,

  • and they put out 95 to 98 percent

    每年 95% 至 98% 的全美國大火

  • of all fires every single year in the US.

    被他們撲滅掉。

  • And from this point on, it was now fire suppression

    從此之後,

  • and not wildfires

    撲滅火災取代了野火,

  • that would become a prime shaper of our forests.

    成為我們森林成形的主要因素。

  • After World War II, timber harvesting got going in the west,

    二次世界大戰後,

  • and the logging removed the large and the old trees.

    西部開始伐木,

  • These were survivors of centuries of wildfires.

    砍伐原木造成大樹和老樹消失。

  • And the forest filled in.

    它們原是百年來野火下的倖存者。

  • Thin-barked, fire-sensitive small trees filled in the gaps,

    森林接著填補上來,

  • and our forests became dense, with trees so layered and close together

    對火敏感的薄皮小樹木補滿了空隙,

  • that they were touching each other.

    我們的森林變成高密度,

  • So fires were unintentionally blocked by roads and railroads,

    樹木近近疊在一起,會彼此碰觸;

  • the cattle and sheep ate the grass,

    道路和鐵路無意間阻斷火的蔓延;

  • then along comes fire suppression and logging, removing the big trees,

    牛和羊吃草;

  • and you know what happened?

    接著而來的人為滅火、 伐木和砍掉大樹,

  • All these factors worked together

    你們可知道發生了什麼事?

  • to allow the forest to fill in,

    所有這些因素一起作用,

  • creating what I call the current epidemic of trees.

    森林填補了間隙,

  • (Laughter)

    造成我稱為「目前樹木氾濫的疫情」。

  • Go figure.

    (笑聲)

  • (Laughter)

    去想想吧。

  • More trees than the landscape can support.

    (笑聲)

  • So when you compare what forests looked like 100 years ago and today,

    樹木的數量遠超過 地景能夠支持的量。

  • the change is actually remarkable.

    因此,比較百年前和現今的森林,

  • Notice how the patchwork has filled in.

    改變其實很驚人。

  • Dry south slopes --

    注意看拼湊之作是怎麼被填補的。

  • they're now covered with trees.

    原本乾燥的南面山坡

  • A patchwork that was once sculptured by mostly small

    現在被樹木覆蓋滿了。

  • and sort of medium-sized fires

    曾經主要由中小型的火災 所塑成的拼湊之作

  • has filled in.

    已經被填補滿了。

  • Do you see the blanket of trees?

    看到樹木的覆蓋層了嗎?

  • After just 150 years,

    僅僅經過 150 年,

  • we have a dense carpet of forest.

    已經有了一片高密度的森林。

  • But there's more.

    還不只如此。

  • Because trees are growing so close together,

    因為樹木生長的距離非常近,

  • and because tree species, tree sizes and ages

    因為長在大片區域中的樹木,

  • are so similar across large areas,

    種類、尺寸、年齡都太相似,

  • fires not only move easily from acre to acre,

    火勢不但很容易從 一英畝延燒到下一英畝,

  • but now, so do diseases and insect outbreaks,

    發生的疾病和昆蟲疫情 也一樣容易傳播,

  • which are killing or reducing the vitality

    因此造成現在的森林

  • of really large sections of forest now.

    大片區域地死亡或衰弱。

  • And after a century without fire,

    一整個世紀沒有火災之後,

  • dead branches and downed trees on the forest floor,

    在森林地面上的枯枝和倒樹

  • they're at powder-keg levels.

    處在一觸即發的層級。

  • What's more, our summers are getting hotter

    此外,夏天越來越熱,

  • and they're getting drier

    越來越乾燥,

  • and they're getting windier.

    風也越來越大 。

  • And the fire season is now 40 to 80 days longer each year.

    如今每年的火季長了 40~80 天。

  • Because of this, climatologists are predicting

    因此,氣候學家預測,

  • that the area burned since 2000

    自 2000 年起燒掉區域的面積,

  • will double or triple

    在接下來三十年間會 變為兩倍或三倍。

  • in the next three decades.

    而我們在這其中蓋房子。

  • And we're building houses in the middle of this.

    兩份近期發佈的研究告訴我們,

  • Two recently published studies tell us

    超過 60% 的新住房

  • that more than 60 percent of all new housing starts are being built

    被建築在這種可燃且危險的地方。

  • in this flammable and dangerous mess.

    所以一旦發生火災,

  • So when we do get a fire,

    會有大片的面積化為灰燼。

  • large areas can literally go up in smoke.

    現在你們對於我一開始

  • How do you feel now

    讓各位看的那張森林圖片

  • about the forest image

    感覺如何?

  • that I first showed you?

    它把我嚇壞了。

  • It scares the heck out of me.

    我們應該怎麼做?

  • So what do we do?

    我們得要恢復拼湊之作的力量。

  • We need to restore the power of the patchwork.

    我們得要把「對」的那種火

  • We need to put the right kind of fire

    再次放回到系統當中。

  • back into the system again.

    這種方式能讓我們改變 許多未來火災的嚴重程度。

  • It's how we can resize the severity of many of our future fires.

    讓人感到欣慰的是

  • And the silver lining is that we have tools

    我們有工具,

  • and we have know-how to do this.

    也有該怎麼做的實際知識。

  • Let's look at some of the tools.

    咱們來看看其中一些工具。

  • We can use prescribed burning to intentionally thin out trees

    我們可以用計畫性火燒(控制燒除)

  • and burn up dead fuels.

    來刻意讓樹木變稀疏,

  • We do this to systematically reduce them and keep them reduced.

    並燒盡可燃物。

  • And what is that going to do?

    這麼做可以系統性地減少 並保持它們於少量。

  • It's going to create already-burned patches on the landscape

    那會有什麼結果?

  • that will resist the flow of future fires.

    那會在地景上創造出 已經燒光的區塊,

  • We can combine mechanical thinning with some of these treatments

    能夠防止未來大火的竄燒。

  • where it's appropriate to do so,

    我們可以把機械式的稀疏做法 和這類處理方式結合,

  • and capture some commercial value

    在適當的情況下這麼做,

  • and perhaps underwrite some of these treatments,

    並獲得一些商業價值,

  • especially around urban areas.

    也許還能承保這類處理方式,

  • And the best news of all is that prescribed burning produces

    特別是在都市地區。

  • so much less smoke than wildfires do.

    最好的消息是計畫性火燒所產生的煙

  • It's not even close.

    遠遠少於野火產生的煙。

  • But there's a hitch:

    差距很大。

  • prescribed burning smoke is currently regulated under air quality rules

    但有個問題:

  • as an avoidable nuisance.

    依目前空氣品質規定的規範,

  • But wildfire smoke?

    計畫性火燒的煙是可避免的妨礙行為。

  • It simply gets a pass.

    但野火的煙呢?

  • Makes sense, doesn't it? (Laughs)

    它沒被規範。

  • So you know what happens?

    合理嗎?(笑聲)

  • We do far too little prescribed burning,

    所以會發生什麼事?

  • and we continually eat smoke in the summers

    我們計畫性的火燒做得太少了,

  • from megafires.

    因而使我們在夏天 持續吸入來自超級大火的煙。

  • We all need to work together to get this changed.

    我們得要同心協力來改變這一點。

  • And finally, there's managed wildfires.

    最後,還有管制野火。

  • Instead of putting all the fires out,

    不要撲滅所有的野火,

  • we need to put some of them back to work

    得要讓其中一些繼續燒下去,

  • thinning forests and reducing dead fuels.

    讓森林變稀疏,減少乾枯的可燃物。

  • We can herd them around the landscape

    我們可以在地景上「放牧」野火,

  • when it's appropriate to do so

    在適當的情況下這樣做,

  • to help restore the power of the patchwork.

    就能協助恢復拼湊之作的力量。

  • And as you've probably figured out by now,

    現在你們可能已經想通了,

  • this is actually a social problem.

    這其實是個社會問題。

  • It's got ecological and climate explanations,

    它的確有生態上和氣候上的解釋,

  • but it's a social problem, and it will take us humans to solve it.

    但它是個社會問題, 需要我們人類來解決。

  • Public support for these tools is poor.

    沒有多少大眾支持這些工具。

  • Prescribed burning and managed wildfires are not well-supported.

    計畫性火燒和管制野火 並沒有受到很好的支持。

  • We actually all simply want fires to magically go away

    事實上我們只想要大火 神奇地自己熄滅掉,

  • and take that pesky smoke with them, don't we?

    也一併帶走討厭的煙,對吧?

  • But there is no future without lots of fire and lots of smoke.

    但未來不可能沒有 多場火災和很多的煙。

  • That option is actually not on the table.

    其實桌面上並沒有這選項。

  • Until we, the owners of public lands, make it our high priority

    直到公共土地的所有者

  • to do something about the current situation,

    將這問題列為優先,

  • we're going to experience continued losses to megafires.

    針對目前的情況行動,

  • So it's up to us.

    不然我們就會繼續經歷 超級大火造成的損失。

  • We can spread this message to our lawmakers,