[Music]
[Applause]
[Music]
there’s a temple in Bali where you have
to be on your guard because the monkeys
that live there have learned a new trick
they watch the tourists what they’re
watching for is the belongings that the
tourists are carrying the monkeys have
evolved a completely new behavior when
they see tourists carrying expensive
objects they’ll jump down
sneak up they’ll take those objects away
and then they’ll climb up and hide on
high spots out of reach but they’re not
trying to get the objects they’re trying
to get food so the sit and taunt the
tourists with their foster grants until
the tourists realize that they have to
pay a ransom and this ransom is in the
form of food which is then paid over to
the monkeys now if that food is
presented in sufficient quantity and the
quality is good enough then the items
that had been stolen are dually returned
to their owners and everybody who
departs happily so the monkeys have
evolved an entirely new way of behaving
this new behavior gets them food and
they’ve learnt it over a period of years
you could almost say that is evolution
so we’ll return to those monkeys a
little bit later on global warming it’s
a phenomenon that variously described
between extremes from we’re doomed mass
extinction is inevitable you’re all
going to die so hey guys soon each
holidays are going to be a lot warmer I
think this needs a little bit more of a
perspective and that’s what I’d like to
look at today that the earth is warming
is not disputed it’s well documented in
scientific evidence and one of the ways
in which this is studies is fascinating
and it involves looking at the oxygen
isotopes in water oxygen exists in two
forms the normal one is oxygen 16 and
the alternative form is oxygen 18
and the difference between the two is
that oxygen-18 has two extra neutrons in
its nucleus and this makes it very
slightly heavier now oxygen is used by
organisms in the water to make chem
shells because it goes through the food
chains and ultimately it appears in
compounds such as calcium carbonate so
organisms and make little shells might
actually reveal how the oxygen
components within the water vary it
turns out that the oxygen-18
is more likely to be in water during
periods of time when the earth is very
cold with ice caps and oxygen-16 is more
likely to be present in the water in
greater quantities when the ice caps are
absent so could the fossils then be used
to reveal to us the history of warming
and cooling events on the earth
well a pioneer in this field was
Professor zanuck shackleton director
Cambridge and he used to work on little
organisms called blobby Jurina
isn’t that beautiful little thing what
Nick did is he developed a technique
which involved analysis of the shells of
these things using mass spectrometry and
using that he was able to work out the
ratios between the two isotopes in the
shells and tally that with the age of
the actual fossil now what was revealed
was that during times when there were
ice caps the water that evaporates into
the air is cooled a little bit more
quickly than at other times and so the
rain and pulls a little bit sooner and
the earliest rain to fall contains most
of the oxygen-18
and the reason for that is oxygenating
is very slightly heavier and therefore
it’s going to condense first and so the
sea is enriched with oxygen 18 meanwhile
the rest of the air carries on towards
the polar regions where it will finally
forward probably as snow but by that
time the oxygen-18 is no longer present
and the air there arrives at the poles
is enriched with oxygen 16 and so as it
falls as snow the snow itself becomes
repository and locks away oxygen-16
so the ice caps at the poles
indisputably egg evidenced by the
fossils and further work recently has
helped to reinforce this this is a
picture of a clam clams are much longer
lived than forum in a fridge which is
the possibly source now these have
annual growth rings and so if you take
these fossils and section them it’s
possible to look at the growth rings
individually and to look at the oxygen
isotope ratios within those rings on an
annual basis thereby gaining a
fluctuating pattern from year to year
but the great rings also show another
difference they show a difference in
thickness depending on how well the
animal was fed that year so on a good
year the growth rings going to be wider
and on a poorer year the growth ring
will be narrower and so it’s possible to
take the shells and to match them up so
that you can determine how the patterns
of growth rings overlap and establish by
comparing successively older shells
eventually with fossil shells a complete
growth ring record going back many years
possibly even thousands of years this is
called sclera chronology and what it’s
allowing scientists to do is to develop
a record we like of global temperature
changes which are recorded in the oxygen
isotopes in the growth rings of the
shells of these clams this is very
similar to the way in which they’ve
collated dendrochronology data to look
at dating with carbon dating as well so
what’s emerging from all of this is the
pattern that shows us that when ice is
present at the poles it locks away the
oxygen-16
and so the sea becomes enriched with
oxygen 18 all Yorkists which live in
there showed an increase in oxygen 18
within their shells at that time
conversely at other times when there are
no poles the reverse is true because the
melting ice returns the oxygen 16 to the
wall
where it dilutes among the whole isotope
ratio the ice itself is also a
repository of information because it
contains the oxygen isotopes too so ice
drills and cores can be used to
reinforce the data which is emerging
what has emerged from the studies of
apostles’ the picture is very firm now
about the warming of the of the earth so
if we have this pattern how far should
we go
before we start descending into mass
panic well it really depends on how you
look at the data I think so let’s
suppose we showed that to global warming
data just over the last hundred years
what you can see is a clear trend the
Earth’s warming up over the last 100
years that’s a convenient timescale
isn’t it because it allows us to point
that finger of accusation a human
pollution industrialization it’s all our
fault but what about if we change that
timescale a little bit and now you look
at it over a period of forty thousand
years now you can see that yes we are in
a period of time when the world’s
warming up
no doubt about it but it’s just another
warming in a repeating natural sequence
of warming and cooling that the earth
has it’s a natural rhythm it’s possible
then that we human beings are just
accelerating what’s already inevitable
so where we upset about that well if the
world is going to warm up the ice caps
are going to go we’re gonna lose
ecosystems habitats are going to go big
cuddly creatures and they’re gonna have
anywhere to live and we’re gonna be a
bit sad he wants the polar bear to get
extinct probably none of us but that
might be an inevitability and so we’re
going to be emotional and worried and
we’re gonna have global agreements
between nations to try and stop all this
ever happening we’re trying to stop
something which is happening
irrespective of our own activities even
if we are accelerating is of course
so what about any perspective so those
are stood here now ten thousand years
ago not today
what would I then be saying to you I’m a
bit upset the woolly mammoth is just
about to go extinct everyone we’re not
gonna see it again big furry animal
great grand creature it’s a tragedy but
what about if I now walk forward in time
from that moment now what do I see I’d
see the emergence of an entirely new
bunch of creatures animals plants I’d
see the emergence of the glorious
biodiversity of a rainforest I’d see the
evolution of intricate new orchids I’d
see the fragrance of a Bluebell wood and
the fabulous biodiversity of a coral
reef see life always finds a way to
bounce back one argument is that
evolution takes an awfully long time
when I’d argue it a little bit
differently from now I think evolution
carries on at a pace that steeps
necessity after all it can’t have taken
those baboons millions of years to learn
the difference between a Cartier and a
Timex so if I really could time travel
like Doctor Who what would I do
well I’d actually go backwards because
I’d want to see the fossil plants I
study growing in their natural
environment and in all that brewery see
what they really were like I might like
to go and see a Tyrannosaurus but I’d
never go forwards because by doing that
I might just spoil the coming
evolutionary surprise thank you
you
[Applause]
[Applause]
[Music]
there’s a temple in Bali where you have
to be on your guard because the monkeys
that live there have learned a new trick
they watch the tourists what they’re
watching for is the belongings that the
tourists are carrying the monkeys have
evolved a completely new behavior when
they see tourists carrying expensive
objects they’ll jump down
sneak up they’ll take those objects away
and then they’ll climb up and hide on
high spots out of reach but they’re not
trying to get the objects they’re trying
to get food so the sit and taunt the
tourists with their foster grants until
the tourists realize that they have to
pay a ransom and this ransom is in the
form of food which is then paid over to
the monkeys now if that food is
presented in sufficient quantity and the
quality is good enough then the items
that had been stolen are dually returned
to their owners and everybody who
departs happily so the monkeys have
evolved an entirely new way of behaving
this new behavior gets them food and
they’ve learnt it over a period of years
you could almost say that is evolution
so we’ll return to those monkeys a
little bit later on global warming it’s
a phenomenon that variously described
between extremes from we’re doomed mass
extinction is inevitable you’re all
going to die so hey guys soon each
holidays are going to be a lot warmer I
think this needs a little bit more of a
perspective and that’s what I’d like to
look at today that the earth is warming
is not disputed it’s well documented in
scientific evidence and one of the ways
in which this is studies is fascinating
and it involves looking at the oxygen
isotopes in water oxygen exists in two
forms the normal one is oxygen 16 and
the alternative form is oxygen 18
and the difference between the two is
that oxygen-18 has two extra neutrons in
its nucleus and this makes it very
slightly heavier now oxygen is used by
organisms in the water to make chem
shells because it goes through the food
chains and ultimately it appears in
compounds such as calcium carbonate so
organisms and make little shells might
actually reveal how the oxygen
components within the water vary it
turns out that the oxygen-18
is more likely to be in water during
periods of time when the earth is very
cold with ice caps and oxygen-16 is more
likely to be present in the water in
greater quantities when the ice caps are
absent so could the fossils then be used
to reveal to us the history of warming
and cooling events on the earth
well a pioneer in this field was
Professor zanuck shackleton director
Cambridge and he used to work on little
organisms called blobby Jurina
isn’t that beautiful little thing what
Nick did is he developed a technique
which involved analysis of the shells of
these things using mass spectrometry and
using that he was able to work out the
ratios between the two isotopes in the
shells and tally that with the age of
the actual fossil now what was revealed
was that during times when there were
ice caps the water that evaporates into
the air is cooled a little bit more
quickly than at other times and so the
rain and pulls a little bit sooner and
the earliest rain to fall contains most
of the oxygen-18
and the reason for that is oxygenating
is very slightly heavier and therefore
it’s going to condense first and so the
sea is enriched with oxygen 18 meanwhile
the rest of the air carries on towards
the polar regions where it will finally
forward probably as snow but by that
time the oxygen-18 is no longer present
and the air there arrives at the poles
is enriched with oxygen 16 and so as it
falls as snow the snow itself becomes
repository and locks away oxygen-16
so the ice caps at the poles
indisputably egg evidenced by the
fossils and further work recently has
helped to reinforce this this is a
picture of a clam clams are much longer
lived than forum in a fridge which is
the possibly source now these have
annual growth rings and so if you take
these fossils and section them it’s
possible to look at the growth rings
individually and to look at the oxygen
isotope ratios within those rings on an
annual basis thereby gaining a
fluctuating pattern from year to year
but the great rings also show another
difference they show a difference in
thickness depending on how well the
animal was fed that year so on a good
year the growth rings going to be wider
and on a poorer year the growth ring
will be narrower and so it’s possible to
take the shells and to match them up so
that you can determine how the patterns
of growth rings overlap and establish by
comparing successively older shells
eventually with fossil shells a complete
growth ring record going back many years
possibly even thousands of years this is
called sclera chronology and what it’s
allowing scientists to do is to develop
a record we like of global temperature
changes which are recorded in the oxygen
isotopes in the growth rings of the
shells of these clams this is very
similar to the way in which they’ve
collated dendrochronology data to look
at dating with carbon dating as well so
what’s emerging from all of this is the
pattern that shows us that when ice is
present at the poles it locks away the
oxygen-16
and so the sea becomes enriched with
oxygen 18 all Yorkists which live in
there showed an increase in oxygen 18
within their shells at that time
conversely at other times when there are
no poles the reverse is true because the
melting ice returns the oxygen 16 to the
wall
where it dilutes among the whole isotope
ratio the ice itself is also a
repository of information because it
contains the oxygen isotopes too so ice
drills and cores can be used to
reinforce the data which is emerging
what has emerged from the studies of
apostles’ the picture is very firm now
about the warming of the of the earth so
if we have this pattern how far should
we go
before we start descending into mass
panic well it really depends on how you
look at the data I think so let’s
suppose we showed that to global warming
data just over the last hundred years
what you can see is a clear trend the
Earth’s warming up over the last 100
years that’s a convenient timescale
isn’t it because it allows us to point
that finger of accusation a human
pollution industrialization it’s all our
fault but what about if we change that
timescale a little bit and now you look
at it over a period of forty thousand
years now you can see that yes we are in
a period of time when the world’s
warming up
no doubt about it but it’s just another
warming in a repeating natural sequence
of warming and cooling that the earth
has it’s a natural rhythm it’s possible
then that we human beings are just
accelerating what’s already inevitable
so where we upset about that well if the
world is going to warm up the ice caps
are going to go we’re gonna lose
ecosystems habitats are going to go big
cuddly creatures and they’re gonna have
anywhere to live and we’re gonna be a
bit sad he wants the polar bear to get
extinct probably none of us but that
might be an inevitability and so we’re
going to be emotional and worried and
we’re gonna have global agreements
between nations to try and stop all this
ever happening we’re trying to stop
something which is happening
irrespective of our own activities even
if we are accelerating is of course
so what about any perspective so those
are stood here now ten thousand years
ago not today
what would I then be saying to you I’m a
bit upset the woolly mammoth is just
about to go extinct everyone we’re not
gonna see it again big furry animal
great grand creature it’s a tragedy but
what about if I now walk forward in time
from that moment now what do I see I’d
see the emergence of an entirely new
bunch of creatures animals plants I’d
see the emergence of the glorious
biodiversity of a rainforest I’d see the
evolution of intricate new orchids I’d
see the fragrance of a Bluebell wood and
the fabulous biodiversity of a coral
reef see life always finds a way to
bounce back one argument is that
evolution takes an awfully long time
when I’d argue it a little bit
differently from now I think evolution
carries on at a pace that steeps
necessity after all it can’t have taken
those baboons millions of years to learn
the difference between a Cartier and a
Timex so if I really could time travel
like Doctor Who what would I do
well I’d actually go backwards because
I’d want to see the fossil plants I
study growing in their natural
environment and in all that brewery see
what they really were like I might like
to go and see a Tyrannosaurus but I’d
never go forwards because by doing that
I might just spoil the coming
evolutionary surprise thank you
you
[Applause]
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