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TEDGlobal 2009

Rachel Pike: The science behind a climate headline

July 24, 2009

In 4 minutes, atmospheric chemist Rachel Pike provides a glimpse of the massive scientific effort behind the bold headlines on climate change, with her team -- one of thousands who contributed -- taking a risky flight over the rainforest in pursuit of data on a key molecule.

Rachel Pike - Atmospheric chemist
Rachel Pike studies climate change at the molecular level -- tracking how emissions from biofuel crops react with the air to shape weather trends globally. Full bio

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Double-click the English subtitles below to play the video.
I'd like to talk to you today about the scale
00:15
of the scientific effort that goes into making
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the headlines you see in the paper.
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Headlines that look like this when they have to do with climate change,
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and headlines that look like this when they have to do with air quality or smog.
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They are both two branches of the same field of atmospheric science.
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Recently the headlines looked like this when the Intergovernmental
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Panel on Climate Change, or IPCC,
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put out their report on the state of understanding of the atmospheric system.
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That report was written by 620 scientists
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from 40 countries.
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They wrote almost a thousand pages on the topic.
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And all of those pages were reviewed by another 400-plus
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scientists and reviewers, from 113 countries.
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It's a big community. It's such a big community, in fact,
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that our annual gathering is the largest scientific meeting in the world.
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Over 15,000 scientists go to San Francisco every year for that.
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And every one of those scientists is in a research group,
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and every research group studies a wide variety of topics.
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For us at Cambridge, it's as varied as the El Niño oscillation,
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which affects weather and climate,
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to the assimilation of satellite data,
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to emissions from crops that produce biofuels, which is what I happen to study.
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And in each one of these research areas, of which there are even more,
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there are PhD students, like me,
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and we study incredibly narrow topics,
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things as narrow as a few processes or a few molecules.
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And one of the molecules I study is called isoprene,
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which is here. It's a small organic molecule. You've probably never heard of it.
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The weight of a paper clip is approximately equal to
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900 zeta-illion -- 10 to the 21st -- molecules of isoprene.
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But despite its very small weight,
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enough of it is emitted into the atmosphere
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every year to equal the weight of all the people on the planet.
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It's a huge amount of stuff. It's equal to the weight of methane.
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And because it's so much stuff, it's really important for the atmospheric system.
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Because it's important to the atmospheric system,
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we go to all lengths to study this thing.
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We blow it up and look at the pieces.
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This is the EUPHORE Smog Chamber in Spain.
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Atmospheric explosions, or full combustion,
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takes about 15,000 times longer than what happens in your car.
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But still, we look at the pieces.
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We run enormous models on supercomputers;
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this is what I happen to do.
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Our models have hundreds of thousands of grid boxes
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calculating hundreds of variables each, on minute timescales.
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And it takes weeks to perform our integrations.
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And we perform dozens of integrations
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in order to understand what's happening.
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We also fly all over the world looking for this thing.
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I recently joined a field campaign in Malaysia. There are others.
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We found a global atmospheric watchtower there,
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in the middle of the rainforest, and hung hundreds of thousands
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of dollars worth of scientific equipment
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off this tower, to look for isoprene,
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and of course, other things while we were there.
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This is the tower in the middle of the rainforest, from above.
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And this is the tower from below.
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And on part of that field campaign we even brought an aircraft with us.
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And this plane, the model, BA146, which was run by FAAM,
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normally flies 120 to 130 people.
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So maybe you took a similar aircraft to get here today.
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But we didn't just fly it. We were flying at 100 meters above the top of the canopy
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to measure this molecule -- incredibly dangerous stuff.
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We have to fly at a special incline in order to make the measurements.
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We hire military and test pilots to do the maneuvering.
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We have to get special flight clearance.
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And as you come around the banks in these valleys, the forces can get up to two Gs.
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And the scientists have to be completely harnessed in
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in order to make measurements while they're on board.
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So, as you can imagine,
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the inside of this aircraft doesn't look like any plane you would take on vacation.
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It's a flying laboratory that we took to make measurements in the region of this molecule.
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We do all of this to understand the chemistry of one molecule.
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And when one student like me has some sort of inclination
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or understanding about that molecule,
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they write one scientific paper on the subject.
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And out of that field campaign we'll probably get
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a few dozen papers on a few dozen processes or molecules.
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And as a body of knowledge builds up,
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it will form one subsection, or one sub-subsection
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of an assessment like the IPCC, although we have others.
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And each one of the 11 chapters of the IPCC
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has six to ten subsections.
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So you can imagine the scale of the effort.
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In each one of those assessments that we write,
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we always tag on a summary,
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and the summary is written for a non-scientific audience.
03:56
And we hand that summary to journalists and policy makers,
03:59
in order to make headlines like these.
04:01
Thank you very much.
04:03
(Applause)
04:05

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Rachel Pike - Atmospheric chemist
Rachel Pike studies climate change at the molecular level -- tracking how emissions from biofuel crops react with the air to shape weather trends globally.

Why you should listen

Rachel Pike knows the intricacies of climate research -- the laborious, exacting and subtle techniques behind findings that end up in IPCC reports and, later, news headlines.

As a Ph.D candidate at Cambridge, Pike's research on isoprene, a major biofuel crop emission, and other molecules has taken her soaring over rainforest canopies in multi-ton labs-on-wings, into the cooled-down sub-levels of supercomputer grids, and into massive experimental atmospheric chambers. Her exhaustive work represents a major step toward a complete picture of how human activity affects the global ecosystem.

The original video is available on TED.com
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