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Cloudy climate change. How clouds affect earth's temperature
模糊的氣候變遷 雲層如何影響地球溫度
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Earth's average surface temperature has warmed by point eight celsius since 1750
地表平均氣溫從1750至今 增加了0.8度
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when carbon dioxide concentration in the atmosphere have doubled
大氣中二氧化碳的濃度增加了一倍
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which is expected before the end of the twenty first century
21世紀末才會發生的改變提早到來
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Researchers project global temperature will have raisen by 1.5 to 4.5 degrees Celsius
研究員預測地球溫度會上升1.5度 變成4.5度
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if the increase is near the low end 1.5 celsius
如果預測的1.5度是最小值
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then we're already half way there
我們已經達到最小值的一半
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we should be more able the adopt with some regions are becoming dryer and less productive
如此一來 某些地方會更乾燥貧瘠
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but others becoming warmer wetter and more productive
另一些卻會更溫暖、潮濕、肥沃
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on the other hand, a rise of 4.5 degree celsius would be similar in magnitude
氣溫提高4.5度後 就相當於發生了
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to the warming that's occur since the last glacier maximum, 22 thousand years ago
兩千兩百萬年前末次冰盛期至今的暖化
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when most of the north America was under ice sheet 2 kilometer's thick
當時北美大半都覆蓋在2公里的冰層底下
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so that would represent the dramatic change of climate
這表示氣候經歷了急遽的變遷
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so it's vitally important for scientists to predict the change in temperature
精確預測溫度的波動刻不容緩
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with as much precision as possible. so the society can plan for the future
人們得及早替未來打算
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the present range of uncertainty simply too large to be confident of how best to respond to climate change
目前氣溫變化幅度太大 無法提出最佳相應措施
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but this estima to 1.5 to 4.5 celsius for doubling the carbon dioxide hasn't change in 35 years
但「二氧化碳增加一倍 氣溫上升1.5到4.5度」的估計 停滯了35年
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why haven't we been able to narrow it down?
為什麼無法再縮小範圍呢?
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the answer is we don't yet understand aerosols in clouds well enough
因為我們還不了解雲朵裡的浮質
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but the new experimentists is tackling the problem
不過已經有人開始做實驗了
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in order to predict how the temperature will change. Scientist need to know some called earth climate sensitivity.
為了預測溫度如何變化 科學家必須知道何謂「氣候敏感性」
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the temperature change in response to radiative forcing
也就是因應輻射強迫 產生的氣溫波動(ΔF為輻射強迫、ΔT為輻射強迫帶來的地表溫度改變)
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A radiat forum set is a temperate imbalace between the energy receive from the sun
輻射效應指的是地球吸收
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and energy radiate back out to space like the imbalance cause by increase of green house gases
和發散的輻射量不平衡 而會不平衡是由於溫室氣體增加了
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to correct imbalance of warms up or cools down,
藉由取得暖化和冷化之間的平衡
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we can determine earth climate sensitivity from the experiment we've already performed in industrial age since 1750.
就能從1750年工業時代做的實驗推知氣候敏感性
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and then the uses number to determine how much more it will warm to varies projected radiated forcing in the twenty first century
然後用相關數字推算21世紀的暖化程度 對輻射效應會有什麼影響
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to do this, we need to know two things.
要達成以上目的 得先知道兩件事
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First, the global temperature rise since 1750.
首先 1750年至今的地球溫度上升了
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And second, the radiative forcing of the present day climate relative to the pre-industrial climate
再來 今天的輻射強迫現象和前工業時期的氣候息息相關
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for the radiative forcing we know that human activities has been increased green house gases in the atmosphere which warm the planet
人類活動增加了大氣中的溫室氣體 讓地球變暖
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but our activities have at the same time increase the amount of aerosols particles in clouds which have cooled the planet.
但同時也增加了雲層裡的氣溶膠粒子(註: 固體或液體 藉吸收或發散輻射影響氣候) 讓地球降溫
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Pre-industrial green house gas concentrations are well measured
前工業時代的溫室氣體濃度很明確
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From bubbles trap in ice course of tent in Greenland and Antarctic.
藉著研究格陵蘭和南極冰塊中的泡泡結構
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So the greenhouse gas forcings are precisely known.
就能知道溫室氣體的影響
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But we have no way of direct recongnition how cloudy it was in 1750.
但畢竟不可能親眼看到1750年代的雲有多少
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And that’s the main source of uncertainty in earth climate sensitivity.
這就是地球氣候敏感性如此不確定的主因
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To understand pre-industrial cloudy is we must use computer models
想了解前工業社會的雲量狀況 就必須用電腦模型輔助
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that reliably simulate the process is responsible for forming nuclei in clouds.
模擬雲裡的形核過程
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Now, to most people aerosols are the things to make your hair stick.
在許多人眼中 氣溶膠就等於髮膠
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But that’s only one type of aerosols.
但髮膠只是氣溶膠的一種
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Atmospheric aerosols are tiny liquid or solid particles suspended in the air.
煙霧質常以微小的液體或固態形式懸浮於大氣中
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There are either primary from dust sea spray salt, burning biomass
第一種主要存在於灰塵、海水、餘燼裡
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Or secondary formed by gas to particle conversion in the atmosphere
第二種是氣體轉換成粒子的產物
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Also known as particle nucleation.
又稱為粒子核化
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Aerosols are everywhere in the atmosphere. And they can block out the sun and polluted urban environments.
大氣中充滿了煙霧質 它們會阻擋太陽光、汙染都市環境
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Or bath distant mountain in blue pace.
或讓遠處山峰染上藍霧
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More importantly the cloud droplet cannot form without an aerosol particle seed.
雲是由煙霧質分子組成的
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So without aerosol particle, there’ll be no clouds.
沒有煙霧質 就沒有雲
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And without clouds, there will be no fresh water.
沒有雲 就沒有淡水
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The climate will be much hotter. And there will be no life.
沒有淡水 天氣會越來越熱 生物就會隨之滅絕
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So we owe our existence to aerosol particles.
有煙霧質分子才有你我的存在
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However, despite their importance how aerosol particles form in the atmosphere
雖然煙霧質在大氣中的形成很重要
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aren’t very effect on clouds and poorly understood.
雲層隱含的意義、
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Even the vapor is responsible for aerosol particle formation and not well established.
蒸氣就能產生煙霧質的道理 卻沒什麼人知道
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Because at present in only might mute amount near one molecule per million million molecules are there.
現在大氣中的煙霧質極少 濃度是一萬億分之一
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This lack of understanding is the main reason for the large uncertainty in climate sensitivity.
缺乏的雲層認識 是無法掌握氣候敏感性的主因
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And the corresponding wild range of future climate projections.
連帶影響到氣候預測
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However, an experiment under way is certain named surprisingly cloud has manage to build a steel vessel
有個名為「驚人雲朵」的實驗正在進行中
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That’s large enough and has low enough contamination that aerosol formation can
他們用龐大的鋼鐵量筒 去掉裡頭雜質 在人為環境下
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For the first time, be measured under tightly controlled atmosphere condition in the bar of tray.
初次測量到了煙霧質的量
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In the first five years of operation, cloud has identified the vapor
研究的頭五年 科學家發現雲就是蒸氣
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responsible for the aerosol formation in the atmosphere.
可以影響大氣中煙霧質的構造
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Which includes sulfuric acid, ammonia amines and biogenic vapours from trees.
煙霧質包括: 硫酸、氨、胺、從樹而來的生物蒸氣
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Using an eye and icing particle bean for the certain proton synchrotron
使用質子同步加速器 以冰粒子的觀點來看
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Cloud is also investigating if galactic cosmic rays enhance the formation of aerosols in clouds.
雲層也可用來探索銀河宇宙線是否會鞏固雲裡的氣膠結構
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This has been suggested as possible unaccounted natural climate forcing agent
有人說宇宙射線可能是影響氣候的天然媒介
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since the flux of cause midgrade raining down in the atmosphere.
因為大氣層裡的豐沛雨量
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There is with solar activity.
會和太陽互相作用
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So cloud is addressing two big questions:
由「雲」可以衍伸出兩個問題:
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Firstly, how cloudy was the pre-industrial climate?
前工業時期有多少雲?
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And hence, how much have clouds changed due to human activities?
人類活動又對那些雲有什麼影響?
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That knowledge will help sharpen climate projections in the 21st century.
尋求這兩個解答 將能更精準預測本世紀的氣候變化
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And simply, could the puzzling observation of solar climate variability in the pre-industrial
觀察前工業時代氣候與太陽變化得到的複雜結果
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be explained by an influence of galactic cosmic rays on the clouds?
是否可用銀河宇宙線對雲層的影響來解釋?
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Ambitious but realistic goals, when your heads in the clouds
探究雲層 追求更加偉大、實際的目標