The science behind a climate headline Rachel Pike
I’d like to talk to you today about the
scale of the scientific effort that goes
into making the headlines you see in the
paper headlines that look like this when
they have to do with climate change and
headlines that look like this when they
have to do with air quality or smog
they’re both two branches of the same
field of atmospheric science recently
the headlines looked like this when the
Intergovernmental Panel on Climate
Change or IPCC put out their report on
the state of understanding of the
atmospheric system that report was
written by 620 scientists from 40
countries they wrote almost a thousand
pages on the topic and all of those
pages were reviewed by another 400 plus
scientists and reviewers from 113
countries it’s a big community it’s such
a big community in fact that our annual
gathering is the largest scientific
meeting in the world over 15,000
scientists go to San Francisco every
year for that and every one of those
scientists is in a research group and
every research group studies a wide
variety of topics for us at Cambridge
it’s as varied as the El Nino
oscillation which affects weather and
climate to the assimilation of satellite
data to emissions from crops that
produce biofuels which is what I happen
to study and in each one of these
research areas of which there are even
more there are PhD students like me and
we study incredibly narrow topics things
as narrow as a few processes or a few
molecules and one of the molecules I
study is called isoprene which is here
the small organic molecule probably
never heard of it the weight of a
paperclip is approximately equal to 900
Zeta iliyan 10 to the 21st molecules of
isoprene but despite its very small
weight enough of it is emitted into the
atmosphere every year to equal the
weight of all the people on the planet
it’s a huge amount of stuff it’s equal
to the weight of methane and because
it’s so much stuff it’s really important
for the atmospheric system because it’s
important for the atmospheric system we
go to all lengths to study this thing we
blow it up and look at the pieces this
is the U for smog chamber in Spain
atmospheric explosions or full
combustion takes about 15,000 times
longer than what happens in your car but
still we look at the pieces we run
enormous models on supercomputers this
is what I happen to do our models have
hundreds of thousands of grid boxes
calculating hundreds of variables each
on minut timescales and it takes weeks
to perform our integrations and we
perform dozens of integrations in order
to understand what’s happening we also
fly all over the world looking for this
thing
recently joined a field campaign in
Malaysia there are others we found a
global atmospheric watchtower there in
the middle of the rainforest
and hung hundreds of thousands of
dollars worth of scientific equipment
office tower to look for isoprene and of
course other things while we were there
this is the tower in the middle of
rainforest from above and this is the
tower from below and on part of that
field campaign we even brought an
aircraft with us and this play in the
model ba one four six which is run by
Pham normally flies 120 to 130 people so
maybe you took a similar aircraft to get
here today but we didn’t just fly it we
were flying at 100 meters above the top
of the canopy to measure this molecule
incredibly dangerous stuff we have to
fly in a special incline in order to
make the measurements we hire military
and test pilots to do the maneuvering we
have to get special flight clearance and
as you come around the banks in these
valleys the forces can get up to 2 GS
and the scientists have to be completely
harnessing in order to make measurements
while they’re on board so as you can
imagine the inside of this aircraft
doesn’t look like any plane you would
take on vacation it’s a flying
laboratory that we took to make
measurements in the region of this
molecule we do all of this to understand
the chemistry of one molecule and when
one student like me has some sort of
inclination or understanding about that
molecule they write one scientific paper
on the subject and out of that field
campaign will probably get a few dozen
papers on a few dozen processes or
molecules and as a body of knowledge
builds up it will form one subsection or
one sub subsection of an assessment like
the IPCC although we have others and
each one of the eleven chapters of the
IPCC has six to ten subsections you can
imagine the scale of the effort in each
one of those assessments that we write
we always tag on a summary and the
summary is written for a non-scientific
audience and we hand that summary to
journalists and policy makers in order
to make headlines like these thank you
very much
you