Rachel Pike: The science behind a climate headline

譯者: Yung Hsiang Tseng 審譯者: Dennis Lin

今天讓我們來談談

I'd like to talk to you today about the scale of the scientific effort

在頭條新聞的背後

that goes into making the headlines you see in the paper.

科學家們所做的種種努力

Headlines that look like this when they have to do with climate change;

這是跟氣候變遷有關的頭條新聞

而這是空氣品質或是煙霧汙染有關的頭條新聞

and like this when they have to do with air quality or smog.

They're two branches of the same field of atmospheric science.

以上兩種新聞內容分別屬於大氣科學的兩個分支

Recently, the headlines looked like this

這是最近的一則頭條，內容是說IPCC...

when the Intergovernmental Panel on Climate Change, or IPCC,

也就是聯合國的"政府間氣候變化專門委員會"

發表了一篇關於大氣系統現況的報告

put out their report

on the state of understanding of the atmospheric system.

這篇報告是由來自40個國家的

That report was written by 620 scientists from 40 countries.

620位科學家合力完成

They wrote almost 1,000 pages on the topic,

整篇報告將近一千頁

and all of those pages were reviewed

然後再經由另外來自113個國家的

by another 400-plus scientists and reviewers

400多位科學家和審查員審定而成

from 113 countries.

It's a big community;

這可是個浩大工程

such a big community, in fact,

that our annual gathering is the largest scientific meeting in the world.

事實上，我們每年的聚會可說是物理學界的年度盛事

Over 15,000 scientists go to San Francisco every year for that.

每年會有超過一萬五千名科學家齊聚於舊金山

Every one of those scientists is in a research group,

每個人都代表一個研究團隊

也代表每個團隊的研究議題

and every research group studies a wide variety of topics.

我們在劍橋的團隊，研究議題非常多樣

For us at Cambridge, it's as varied as the El Niño Oscillation,

像是影響天氣與氣候的聖嬰現象

which affects weather and climate,

to the assimilation of satellite data,

人造衛星的數據同化

to emissions from crops that produce biofuels, which is what I study.

或是我正在研究的農作物與生化燃料

And in each one of these research areas, of which there are even more,

而在每個研究領域裡

都有許多跟我一樣的博士生

there are PhD students, like me, and we study incredibly narrow topics,

每人負責一個專精的主題

things as narrow as a few processes or a few molecules.

專精到像是小小的反應過程，或一些小分子

我研究的是名叫異戊二烯的分子，如螢幕所示

And one of the molecules I study is called isoprene, which is here.

這是種微小的有機分子，你們可能從來沒聽過

It's a small organic molecule.

You've probably never heard of it.

The weight of a paper clip is approximately equal

一個迴紋針的重量

大約等於10的21次方個異戊二烯分子

to 900 zeta-illion -- 10 to the 21st -- molecules of isoprene.

But despite its very small weight,

雖然它非常輕

enough of it is emitted into the atmosphere every year

但它每年排放到大氣中的量

卻相當於地球上所有人的體重總和

to equal the weight of all the people on the planet.

這可不是團小東西，跟甲烷的重量比起來也不相上下

It's a huge amount of stuff. It's equal to the weight of methane.

正因如此，它在大氣系統中扮演了至關重要的角色

And because it's so much stuff,

it's really important for the atmospheric system.

我們會不遺餘力地研究異戊二烯

Because it's important to the atmospheric system,

理由也在此

we go to all lengths to study this thing.

我們將它炸裂並觀察它遺留的碎片

We blow it up and look at the pieces.

這是位於西班牙的EUPHORE煙霧實驗室

This is the EUPHORE Smog Chamber in Spain.

大氣中的完全燃燒

Atmospheric explosions, or full combustion,

所產生的爆炸次數是車子引擎裡的一千五百倍

takes about 15,000 times longer than what happens in your car.

即使如此，我們仍致力於觀察它的碎片

But still, we look at the pieces.

We run enormous models on supercomputers; this is what I happen to do.

我們會用超級電腦運算大量的模型

我目前在做的就是這個

Our models have hundreds of thousands of grid boxes

模型裡有上千個網格在運算

calculating hundreds of variables each, on minute timescales.

每分鐘能運算上百筆數據

It takes weeks to perform our integrations,

而整合這些數據則花費了數週時間

and we perform dozens of integrations in order to understand what's happening.

整合次數也不計其數

耗費那麼多心力只為了更瞭解異戊二烯

We also fly all over the world looking for this thing.

此外，我們也在世界各地尋找這種分子

I recently joined a field campaign in Malaysia -- there are others.

最近我參加了一個在馬來西亞的實地調查活動

We found a global atmospheric watchtower there

我們還在當地建立了一個全球大氣觀測站

in the middle of the rainforest,

就位在雨林中央，上面懸掛了許多昂貴的科學儀器

and hung hundreds of thousands of dollars' worth of scientific equipment

價值約數十萬美元

都是為了尋找異戊二烯

off this tower,

to look for isoprene and other things while we were there.

當然，也順便觀察其他種類的分子

這就是那座觀測站，照片是從飛機上拍的

This is the tower in the middle of the rainforest from above,

這張是從底下拍的

and the tower from below.

我們還從FAAM借來了一架BA146飛機進行觀測

On part of that field campaign we even brought an aircraft with us.

(譯註：FAAM是英國一家提供大氣觀測機的機構)

And this plane, the model BAe-146, which was run by FAAM,

這種飛機載客量約120到130人

normally flies 120 to 130 people,

so maybe you took a similar aircraft to get here today.

也許有人今天就是乘坐類似的飛機來到這裡的

But we didn't just fly it.

但我們是以距離樹冠層僅一百公尺的高度在飛行

We were flying at 100 meters above the top of the canopy

非常危險，但這都是為了測量異戊二烯

to measure this molecule -- incredibly dangerous stuff.

We have to fly at a special incline to make the measurements;

為了進行測量，飛機必須以一特定角度飛行

we hire military and test pilots to do the maneuvering;

所以我們請來了軍方和測試飛行員來駕駛飛機

當然，特殊的飛行許可也是不可少的

we need special flight clearance.

當飛機沿著河谷飛過時，G力會達到2G

As you come around the banks in these valleys,

the forces can get up to two Gs;

科學家們必須完全承受住這些壓力

the scientists must be completely harnessed in

因為他們還要在飛機上進行測量事宜

in order to make measurements while on board.

所以，各位應該可以想像

So as you can imagine,

飛機上的狀況絕對不會像要去度假一樣悠閒

the inside of the aircraft doesn't look like one you'd take on vacation.

對我們而言，那就像個空中實驗室

It's a flying laboratory we took to make measurements of this molecule.

We do all this to understand the chemistry of one molecule.

以上就是我們為了瞭解一個化學分子所做的努力

And when one student like me has some sort of inclination

只要有某個學生像我一樣特別執著於某一種分子

或對某一種分子有著深入了解

or understanding about that molecule,

他們就會把自己的想法寫成一篇篇的論文

they write one scientific paper on the subject.

藉由一個實地調查活動，我們可以瞭解許多分子

And out of that field campaign we'll probably get a few dozen papers

許許多多的研究論文便應運而生

on a few dozen processes or molecules.

我們的知識體系便由此而建構

As a body of knowledge builds up, it will form one subsection,

進而衍生出更進一步的研究與探索

or one sub-subsection,

of an assessment like the IPCC, although we have others.

這些研究結果於是成為IPCC評估報告的構成要素

And each one of the 11 chapters of the IPCC has six to ten subsections.

在報告書的十一個章節裡頭

每章都有六到十小節闡述進一步的研究成果

So you can imagine the scale of the effort.

所以各位可以想像，科學家們為此付出了多少心力

In each one of the assessments we write, we always tag on a summary,

報告完成之後，我們會將報告書的內容...

整理成一篇摘要

and the summary is written for a non-scientific audience.

以提供給非專業領域的大眾閱讀

And we hand that summary to journalists and policy makers

最後我們把這篇摘要交給記者以及政府的決策官員

in order to make headlines like these.

報紙上的頭條新聞便由此而生

謝謝大家

Thank you very much.

(Applause)

(掌聲)