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  • From 2016 to 2019,

    譯者: Regina Chu 審譯者: Marssi Draw

  • meteorologists saw record-breaking heat waves around the globe,

    從 2016 到 2019 年

  • rampant wildfires in California and Australia,

    氣象學家看到全球各地破紀錄的熱浪

  • and the longest run of category 5 tropical cyclones on record.

    加州及澳洲的野火肆虐

  • The number of extreme weather events has been increasing for the last 40 years,

    及史上持續最久的五級熱帶氣旋

  • and current predictions suggest that trend will continue.

    過去四十年,極端天氣事件不斷增加

  • But are these natural disasters simply bad weather?

    目前的預報顯示這種趨勢將持續下去

  • Or are they due to our changing climate?

    但是這些天災只是壞天氣而已嗎?

  • To answer this question

    或是因為氣候變遷造成?

  • we need to understand the differences between weather and climate

    要回答這個問題

  • what they are, how we predict them, and what those predictions can tell us.

    我們必須了解天氣與氣候的不同

  • Meteorologists define weather as the conditions of the atmosphere

    這兩者是什麼,要怎麼預報 及這些預報能告訴我們什麼

  • at a particular time and place.

    氣象學家定義天氣

  • Currently, researchers can predict a region's weather for the next week

    為大氣在某時某地的狀態

  • with roughly 80% accuracy.

    目前,研究人員可以預報 某一個區域下一週的天氣

  • Climate describes a region's average atmospheric conditions

    準確度大約是 80%

  • over periods of a month or more.

    氣候則描述某個區域的平均大氣狀態

  • Climate predictions can forecast average temperatures for decades to come,

    通常是一個月或更長時間的平均值

  • but they can't tell us what specific weather events to expect.

    氣候預報可以預測 未來數十年的平均溫度

  • These two types of predictions give us such different information

    但是不能告訴我們具體的天氣為何

  • because they're based on different data.

    這兩種預報會給我們大不相同的資訊

  • To forecast weather,

    是因為它們以不同的數據為基礎

  • meteorologists need to measure the atmosphere's initial conditions.

    要預報天氣

  • These are the current levels of precipitation, air pressure, humidity,

    氣象學家需要觀測大氣的初始條件

  • wind speed and wind direction that determine a region's weather.

    包括目前的降雨量、氣壓、濕度

  • Twice every day, meteorologists from over 800 stations around the globe

    風速及風向等等 這些都會決定某區域天氣的條件

  • release balloons into the atmosphere.

    全球八百多個氣象站的 氣象學家會每天兩次

  • These balloons carry instruments called radiosondes,

    釋放氣球進入大氣中

  • which measure initial conditions

    這些氣球帶著稱作 無線電探空儀的儀器

  • and transmit their findings to international weather centers.

    會觀測初始條件

  • Meteorologists then run the data through predictive physics models

    然後把結果傳輸到各個國際氣象中心

  • that generate the final weather forecast.

    氣象學家再用預報物理模式跑數據

  • Unfortunately, there's something stopping this global web of data

    產生最終的天氣預報

  • from producing a perfect prediction:

    可惜,有些東西會阻礙這個全球數據網

  • weather is a fundamentally chaotic system.

    產生完美的預報:

  • This means it's incredibly sensitive and impossible to perfectly forecast

    天氣本身就是一個混沌系統

  • without absolute knowledge of all the system's elements.

    這意味著它非常敏感

  • In a period of just ten days,

    如果沒有系統所有要素的絕對知識 不可能產生完美預報

  • even incredibly small disturbances can massively impact atmospheric conditions

    在短短的十天內

  • making it impossible to reliably predict weather beyond two weeks.

    即使是極細微的干擾

  • Climate prediction, on the other hand, is far less turbulent.

    也可以對大氣狀態產生極大的影響

  • This is partly because a region's climate is, by definition,

    無法準確預測兩週後的氣象

  • the average of all its weather data.

    另一方面氣候預報就沒有這麼亂

  • But also because climate forecasts ignore

    部分原因是某地區的氣候按定義來說

  • what's currently happening in the atmosphere,

    是其所有氣象數據的平均值

  • and focus on the range of what could happen.

    但也是因為氣候預報

  • These parameters are known as boundary conditions,

    會忽略目前大氣正在發生的事

  • and as their name suggests, they act as constraints on climate and weather.

    而專注在可能會發生什麼的範圍

  • One example of a boundary condition is solar radiation.

    這些參數是所謂的邊界條件

  • By analyzing the precise distance and angle between a location and the sun,

    如同字面所說

  • we can determine the amount of heat that area will receive.

    它們扮演氣候及氣象的限制條件

  • And since we know how the sun behaves throughout the year,

    邊界條件的一個例子就是日射

  • we can accurately predict its effects on temperature.

    透過分析某位置和太陽之間的 精確距離及角度

  • Averaged across years of data,

    我們可以算出那個區域 會接收多少熱能

  • this reveals periodic patterns, including seasons.

    既然我們知道太陽一年的變化

  • Most boundary conditions have well-defined values that change slowly, if at all.

    我們就可以準確預測它對溫度的影響

  • This allows researchers to reliably predict climate years into the future.

    把跨數年的數據取平均值

  • But here's where it gets tricky.

    就會揭示周期性的模式,包括季節

  • Even the slightest change in these boundary conditions

    大多數邊界條件都有明確定義的值 這些值如果有變化也非常緩慢

  • represents a much larger shift for the chaotic weather system.

    這讓研究人員能確實預報 未來幾年的氣候

  • For example, Earth's surface temperature has warmed by almost 1 degree Celsius

    但這也是事情變得棘手的地方

  • over the last 150 years.

    即使這些邊界條件僅有細微的變化

  • This might seem like a minor shift,

    也會讓混沌的天氣系統產生大幅變化

  • but this 1-degree change has added the energy equivalent

    例如,地球表面溫度

  • of roughly one million nuclear warheads into the atmosphere.

    在過去 150 年已經暖化了 將近攝氏一度

  • This massive surge of energy has already led to a dramatic increase

    聽起來變化不大

  • in the number of heatwaves, droughts, and storm surges.

    但是這個一度的改變增加的能量當量

  • So, is the increase in extreme weather due to random chance, or changing climate?

    等於發射一百萬個核子彈頭進入大氣

  • The answer is that

    這麼巨大的能量驟增已經導致

  • while weather will always be a chaotic system

    熱浪、乾旱及風暴潮的數量急劇增加

  • shifts in our climate do increase the likelihood of extreme weather events.

    所以,極端天氣事件會增加 只是隨機發生還是因為氣候變化?

  • Scientists are in near universal agreement that our climate is changing

    答案是

  • and that human activity is accelerating those changes.

    雖然天氣永遠都是混沌系統

  • But fortunately,

    氣候變化的確會增加 極端天氣的可能性

  • we can identify what human behaviors are impacting the climate most

    科學家目前幾乎已達到共識 就是我們的氣候正在改變

  • by tracking which boundary conditions are shifting.

    而人類的活動正在加速這些變化

  • So even though next month's weather might always be a mystery,

    幸運的是

  • we can work together to protect the climate for centuries to come.

    我們可以找出什麼樣的人類行為 對氣候的影響最大

From 2016 to 2019,

譯者: Regina Chu 審譯者: Marssi Draw

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