00:00:00
so we're going to be talking today
00:00:03
about a geological period
00:00:07
that i think of all the geological
00:00:09
periods may have
00:00:11
the greatest consequence on our life
00:00:14
today
00:00:15
and so what we're going to be doing is
00:00:18
looking
00:00:18
at this particular point in time
00:00:23
i have sort of a a personal legacy that
00:00:26
ties me to
00:00:27
the carboniferous and it goes back to
00:00:31
when i was a kid when i was
00:00:33
probably 10 or 11 somewhere in there my
00:00:36
father was a bunch of other folks local
00:00:39
people
00:00:40
bought a hunting camp in the mountains
00:00:42
of western pennsylvania
00:00:44
and the allegheny mountains and it was a
00:00:47
bit more rustic than
00:00:48
the one shown here but it was a
00:00:50
wonderful place to go
00:00:51
as a kid to hike and hunt and fish it
00:00:54
was just
00:00:56
just one of my favorite places in the
00:00:58
world and
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it's a whoops
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it was in the allegheny mountains a
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beautiful countryside
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and at that time i was
00:01:11
interested in geology i'd been
00:01:14
collecting rocks
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for years
00:01:19
and so my parents bought me books about
00:01:21
geology to what my interest
00:01:24
and they talked about how the earth had
00:01:26
changed and that just didn't
00:01:28
resonate with me i couldn't quite get a
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hold of the sense that
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there had been such vast changes in
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the character of the earth and
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so one day i was walking along one of
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the trails
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and i looked down and there was a funny
00:01:47
rock
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a rock that i'm right now holding in my
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hand
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and when i picked that up i realized i
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had something
00:01:59
that really didn't belong to this
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particular landscape
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i didn't know what it was but i was
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pretty sure it was part of a fossil
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plant
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and my guess was it was a fossil palm
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tree
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and that said that the world had
00:02:14
definitely changed it brought home
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to me how much variation
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there has been on this planet through
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geologic time
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whoops that was a rock just falling on
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the floor
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they uh
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and uh so i think that particular
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experience was it factored into my
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decision
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some years later to major in geology at
00:02:40
ohio state
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and the rest is kind of history
00:02:48
then i got back to the carbon difference
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again
00:02:51
when i did my phd dissertation on a
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carboniferous limestone
00:02:55
that cropped out around the bay of fundy
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in nova scotia
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and that was sort of the last time i
00:03:03
really worked on
00:03:04
the carboniferous i had one other
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carboniferous experience it was
00:03:08
it was kind of funny i
00:03:13
took a field trip participated in a
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field trip as a participant
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um and colorado looking at
00:03:22
some shallow marine carboniferous
00:03:25
deposits there and we started off the
00:03:27
very first day
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in a quarry that was abandoned
00:03:32
and uh pretty much overgrown but
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could still see lots of rocks and we got
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there
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and the field trip leader who was a
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friend of mine from the university of
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indiana
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said right off the bat well
00:03:47
a year ago ed clifton was in my office
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and i showed him
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several little samples from this quarry
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and i asked him
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what they were and he glanced at them
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and said oh
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those are tidal deposits
00:04:02
so ed why don't you show us what it is
00:04:04
about this quarry
00:04:06
that makes it tidal well talk about
00:04:09
being put on the spot
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i've never seen these rocks before in my
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life
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so i i started to stall for time i
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started talking about all of the things
00:04:21
we might look for and i got the group
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together in a
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spot where i could look out and sort of
00:04:27
see the whole quarry and look at places
00:04:30
identify places that we could look to
00:04:31
see if we could find some of these
00:04:33
things and sure enough we went out then
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and we found them and my my reputation
00:04:37
was
00:04:38
still intact but i think that was
00:04:42
probably the point which i was most put
00:04:45
on the spot
00:04:46
since maybe i took my roles at johns
00:04:49
hopkins or something like that
00:04:52
in any event i haven't had much
00:04:54
experience with the
00:04:55
for a sense but it's always remained one
00:04:58
of
00:04:58
i think the parts of the geologic record
00:05:02
that i
00:05:03
i find most intriguing
00:05:15
so what is the carboniferous it is a
00:05:18
period of time
00:05:20
that extended between 300 and 360
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million
00:05:24
years in the past
00:05:27
and geologists divide
00:05:32
time up into periods each one with sort
00:05:36
of its own flavor its own set of
00:05:38
organisms its its
00:05:39
its own character and every one of these
00:05:44
has contributed to our world today
00:05:47
each one has in its own way manifested
00:05:50
itself
00:05:51
in our current environment our current
00:05:54
living
00:05:56
some more than others
00:05:59
probably the period that is most
00:06:02
familiar
00:06:03
to people today is the jurassic
00:06:06
thanks to all the publicity it has had
00:06:09
in recent years
00:06:10
so what does the what's
00:06:14
what are the legacies of the jurassic
00:06:17
period
00:06:18
well birds originated in the jurassic
00:06:21
and um that certainly is important in
00:06:24
our modern world
00:06:25
but otherwise not a whole lot a book
00:06:29
or movies and that's pretty much the
00:06:32
legacy
00:06:32
of the jurassic
00:06:36
on the other hand the carboniferous has
00:06:38
numerous legacies
00:06:40
that extend into our world today
00:06:43
and it's those that i'm going to be
00:06:44
talking about the rest of this talk
00:06:49
it was a time of really dense
00:06:52
lush vegetative growth huge swamps
00:06:55
and forests that existed and some very
00:06:59
strange animals that lived there
00:07:01
so what are the legacies of
00:07:04
the carboniferous well
00:07:08
it had a global climate that was most
00:07:11
like our own
00:07:13
in the last 400 million years
00:07:16
so we can really identify our climate
00:07:19
today or our world today with that
00:07:21
of the carboniferous it was a remarkable
00:07:25
period in the evolution of plants
00:07:27
we'll see some of those plants later on
00:07:31
and it is where we see our oldest
00:07:35
identifiable ancestors in our
00:07:38
particular line from primates to
00:07:42
vertebrates
00:07:45
and it exasperated
00:07:49
an extinction event that opened the door
00:07:52
to dinosaurs and mammals
00:07:55
and we are
00:07:59
it fueled the industrial revolution and
00:08:02
it shaped our modern world
00:08:04
that way and it contributes to a
00:08:06
contemporary threat the likes of which
00:08:09
we've not seen
00:08:12
so you're invited to a field trip to the
00:08:14
carboniferous
00:08:16
i recommend that you bring rain gear and
00:08:18
waterproof
00:08:19
boots it's going to be pretty wet back
00:08:21
there and
00:08:22
oh yes a really effective
00:08:25
insect repellent might come in very
00:08:28
handy
00:08:31
so what was the world like as we went
00:08:33
into the carboniferous
00:08:35
in the late devonian the period just
00:08:37
before the carboniferous we had two
00:08:39
continents laurasia and gondwana
00:08:42
and they were moving together gondwana
00:08:45
was
00:08:46
creeping north towards eurasia
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by the middle of the carboniferous it is
00:08:51
just about arrived
00:08:54
the two continents are starting to merge
00:08:57
there are lots of low
00:08:58
lowlands and shallow marine
00:09:02
areas that are opened up because of this
00:09:06
and then and also
00:09:09
at that time north america and western
00:09:11
europe are joined on the
00:09:13
eurasian continent the rift that will be
00:09:17
the mid-atlantic rift that separates the
00:09:19
two plates today hadn't yet developed
00:09:22
so north america and western europe are
00:09:25
on the same continent and
00:09:26
in about the same latitude which becomes
00:09:29
important a little bit later on
00:09:33
by the end of the carboniferous the two
00:09:36
continents had really
00:09:37
jammed into one another and where
00:09:40
before there had been lots of swamps and
00:09:44
and uh wetlands there are now mountain
00:09:47
ranges that are building
00:09:49
and it is a time of
00:09:52
glacial development in antarctica
00:09:56
and a climate probably pretty close to
00:09:59
the present day
00:10:02
climate
00:10:06
so in the united states
00:10:09
in the early part of the
00:10:13
carboniferous much of the country would
00:10:17
have been covered by
00:10:18
a shallow inland sea and then
00:10:21
as time progressed and we go into the
00:10:23
latter part of the
00:10:24
carboniferous we get extensive swamps
00:10:28
building out into that sea
00:10:31
and if you remember this sample of mine
00:10:34
it came from approximately right there
00:10:37
in the middle
00:10:38
of these great swamps that were building
00:10:40
out in the latter part
00:10:41
of the of the carboniferous
00:10:45
and because we have these these two
00:10:47
different types of
00:10:49
deposition marine deposition first and
00:10:52
then the non-marine deposition
00:10:54
a lot after that
00:11:00
the north american carboniferous
00:11:04
is really divided into two periods the
00:11:07
mississippian period
00:11:08
which is dominated by marine deposits
00:11:11
overlaid by the pennsylvanian period
00:11:14
which is overlapping which is consists
00:11:16
of the
00:11:18
non-marine deposits
00:11:22
whereas the rest of the world keeps them
00:11:25
lumped together in the carboniferous
00:11:26
period that's what we will do
00:11:28
here i won't break it into the
00:11:30
pennsylvanian and
00:11:31
the mississippian
00:11:36
so why the carboniferous period what
00:11:39
makes it special
00:11:40
well it was a very lush green world that
00:11:44
was dominated
00:11:45
by plants and this was
00:11:48
kind of a first in the evolution of the
00:11:50
earth
00:11:52
back 500 million years ago
00:11:56
there were plants in the sea but on
00:11:59
shore
00:12:00
it was pretty much a bleak and barren
00:12:03
landscape
00:12:07
by the time we get into the solarian and
00:12:10
about 480
00:12:12
million years ago we're starting to see
00:12:14
plants
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creep out of the water and starting to
00:12:18
colonize the land
00:12:20
to do that they had to make a couple of
00:12:22
evolutionary changes
00:12:24
a couple of hoops to jump through
00:12:28
and one of these
00:12:30
[Music]
00:12:34
was the development of a waterproof
00:12:36
cover because if you
00:12:38
are a plant and you don't have a
00:12:41
waterproof cover you're going to dry out
00:12:42
pretty fast
00:12:44
if you leave the safety of
00:12:47
the ocean or fresh water what
00:12:50
whatever the water body you're
00:12:53
in so one of the things that the plants
00:12:56
evolved
00:12:58
developed was this cover very much like
00:13:01
a sheet of plastic
00:13:02
in many regards
00:13:05
that retained the water inside the plant
00:13:09
but plants also have to
00:13:12
breathe they have to bring in carbon
00:13:16
dioxide
00:13:16
for their photosynthesis and
00:13:20
in order to do that they had to have
00:13:22
openings
00:13:23
in that cuticle and the openings were
00:13:26
formed by
00:13:27
what are called stomatas little little
00:13:31
sets of cells that would fill with water
00:13:33
and get distended
00:13:35
when they got distended they would be
00:13:36
open as they are in the upper
00:13:38
upper right and then
00:13:42
or the upper left i'm dyslexic
00:13:47
and then they when they wanted to close
00:13:50
so that they didn't lose water
00:13:52
they'd release the water from those
00:13:54
cells
00:13:55
they'd collapse and it would close up
00:13:58
and so that
00:13:58
provided them with a mechanism for
00:14:01
essentially breathing
00:14:03
that was necessary another another step
00:14:06
in their movement
00:14:07
onto the land and so
00:14:10
some of the early ones probably looked
00:14:12
very much like modern day liverwort a
00:14:16
plant that is
00:14:17
is pretty primitive in its character
00:14:22
well so far the plants were really tied
00:14:24
to bodies of water
00:14:26
they needed to have the water available
00:14:30
for their survival
00:14:33
and to get away from the water they need
00:14:36
to develop
00:14:37
a vascular plant system which means
00:14:41
xylem and phloem uh the xylem
00:14:45
are essentially water mains they're made
00:14:47
of dead plant material
00:14:49
they're watertight and so the water
00:14:51
moves by capillary action
00:14:53
through them throughout the entire plant
00:14:56
and then
00:14:57
the phloem on the other hand are made of
00:15:00
living cells
00:15:01
and they're perforated where they join
00:15:03
so that
00:15:04
water can escape with the sugar
00:15:08
that is provided by the leaves
00:15:11
can be transported throughout the plant
00:15:13
and it can
00:15:14
in this way be fed and once plants
00:15:18
developed
00:15:18
this vascular plant system they could go
00:15:21
anywhere
00:15:22
where there was water in the soil so
00:15:25
this freed them
00:15:26
completely from their bonds to
00:15:29
upstanding bodies of water
00:15:34
this happened in the devonian before the
00:15:37
carboniferous
00:15:38
and it was at that time we got the first
00:15:42
trees and the first forests
00:15:48
so we get into the carboniferous and
00:15:52
what's happening is these continents are
00:15:54
starting to move together
00:15:56
they're starting to merge and so there
00:15:58
are lots of
00:15:59
low wet areas in a zone that is
00:16:03
typically pretty wet
00:16:04
between the tropic of capricorn and
00:16:07
tropic of cancer i think but i'd
00:16:10
have to check on that but i think that's
00:16:12
what it is
00:16:13
anyway 30 degrees north and south of
00:16:16
the equator is a wet zone and this
00:16:19
is where our carboniferous deposits
00:16:22
are accumulating in things that are
00:16:25
probably much like this peat swamp
00:16:27
in barneo
00:16:30
so a carboniferous swamp might look like
00:16:33
this
00:16:35
lots of strange vegetation and
00:16:39
some real peculiar forests with
00:16:43
some strange strange trees
00:16:47
this is a tree that grew up 150 to
00:16:50
up to 150 feet tall calamities
00:16:54
um it was hollow on the inside it was
00:16:57
bamboo like
00:16:59
in its trunk and it stems
00:17:05
it was a wetland tree that formed in the
00:17:08
low
00:17:08
wet areas
00:17:11
and you might see a similarity with its
00:17:15
modern day
00:17:16
counterpart although some of them
00:17:19
looked a bit different they're still the
00:17:22
same
00:17:23
general kind of structure and we see it
00:17:25
today
00:17:26
you probably all have seen this horse
00:17:29
tail
00:17:30
rushes or equisetums
00:17:33
these are the living relatives
00:17:36
of those great trees of the
00:17:37
carboniferous
00:17:40
there's another tree called
00:17:42
archaeopterus which is really kind of
00:17:44
confusing
00:17:45
confusing because archaeopteryx
00:17:49
was a very early fossil
00:17:52
bird so this is
00:17:56
a tree and a tall tree
00:18:00
but if you look at the leaves in the
00:18:02
upper
00:18:04
left-hand corner
00:18:07
you see their leaves are very much like
00:18:09
ferns and these were just
00:18:11
giant fern trees
00:18:16
then there were the scale trees those
00:18:18
called because their barks
00:18:19
looked scaly and there were two of these
00:18:22
that were particularly prominent
00:18:24
one of them is lipodendron
00:18:28
lepidendron could form really tall trees
00:18:31
and notice they on the
00:18:34
left-hand side the things that look like
00:18:37
pine gold hanging down
00:18:39
those are not pine cones this is not a
00:18:41
pine they're spore cases
00:18:44
and they grew out on the ends of those
00:18:47
branches as sort of the last bit of
00:18:50
growth
00:18:51
on a branch would be a spore case
00:18:54
and so the tree would grow produce the
00:18:57
spore cases
00:18:59
and then couldn't grow anymore and that
00:19:01
was the end of its life
00:19:03
so they would reproduce once at the end
00:19:05
of the life
00:19:06
they could get up to 100 feet tall
00:19:12
another scale tree that was related to
00:19:14
them you can sort of see why they were
00:19:15
called scale trees
00:19:17
in this artist's recognition
00:19:20
the singularia singularia was a similar
00:19:23
tree sort of hollow stumped
00:19:26
um sometimes you could find casts of the
00:19:29
almost the entire tree as in this
00:19:33
example from great britain
00:19:37
and i had a strange root system because
00:19:40
the things that look like roots here
00:19:41
aren't really roots they're really
00:19:43
branches that are branching out
00:19:45
below the surface of the ground
00:19:49
and the roots are attached to these
00:19:54
little rootlets that fasten on each one
00:19:57
of these little spots
00:19:58
is a place where one of these rootlets
00:20:02
attached and if that looks kind of
00:20:04
familiar
00:20:06
well yeah there it is
00:20:09
so what i've got here is a cast
00:20:13
of a root of a singularia or a
00:20:17
lepidendren they're both pretty much the
00:20:19
same in their root structure
00:20:21
and so i'm seeing the roots of a fossil
00:20:25
extinct tree
00:20:29
so these were the scale trees they were
00:20:32
they were
00:20:32
a major component of the carboniferous
00:20:35
forest
00:20:38
and today they're represented there's
00:20:41
their
00:20:41
family is still around but they're quill
00:20:44
warts and quill warts
00:20:45
i'd never heard of before but they are
00:20:48
aquatic plants or semi-aquatic plants
00:20:50
that live in the cooler climates of
00:20:53
the world that's what's left of the
00:20:56
scale trees
00:20:57
today
00:21:01
the rainforest provided
00:21:04
space and food for a lot of animals that
00:21:08
were developing
00:21:11
amphibians first came ashore first
00:21:14
developed
00:21:15
in the preceding period and during the
00:21:17
devonian
00:21:19
and basically fish got into shallow
00:21:23
water
00:21:24
and eventually developed lungs to help
00:21:26
them breathe
00:21:27
and use their fins to move about in a
00:21:30
very shallow water and these became
00:21:32
feet and so we've had the first
00:21:35
quadrupeds
00:21:37
which are these devonian amphibians
00:21:40
but the amphibians are still tied to the
00:21:43
water
00:21:44
and they're tied to the water because
00:21:46
their eggs
00:21:47
don't have a protective shell they're
00:21:50
just a membrane
00:21:51
and if they're not in the water they dry
00:21:54
out and
00:21:55
the embryonic forms are lost
00:22:01
so in the carboniferous very likely
00:22:05
the amphibians were laying their eggs in
00:22:07
shallower in the shallowest water they
00:22:09
could get away with because that would
00:22:11
be
00:22:11
the safest from marine or freshwater
00:22:15
predators that lived in the water fish
00:22:17
particularly that would feed on the eggs
00:22:20
and eventually the eggs got to the point
00:22:24
where they started to have a case
00:22:27
that was not breakable was not permeable
00:22:30
it was something that could be taken
00:22:32
with the water in it
00:22:34
and carried away from water
00:22:38
so a little reptile could develop inside
00:22:42
an egg even though the egg
00:22:45
were completely out of the water because
00:22:47
it carried
00:22:48
the water with it and sealed it
00:22:52
and so this broke the bond then of
00:22:55
the reptiles or allowed the reptiles to
00:22:58
develop broke the bond that the
00:23:00
amphibians had
00:23:01
with the water and allowed reptiles
00:23:04
to move away and to actually occupy
00:23:08
the earth's surface this
00:23:11
is the earliest confirmed of
00:23:14
reconstruction of the earliest confirmed
00:23:17
reptile
00:23:18
about 312 million years which is
00:23:21
getting toward the late uh carboniferous
00:23:25
about eight to ten inches long would not
00:23:27
look particularly out of place in a
00:23:29
forest
00:23:30
today
00:23:34
this is a little reptile
00:23:38
that is the oldest known diopside
00:23:41
reptile
00:23:42
diopside what does that mean
00:23:46
and why is it important
00:23:50
vertebrates come with essentially three
00:23:53
different types of skulls
00:23:55
depending upon the number of openings
00:23:58
besides the eye socket
00:23:59
and the nostril the anapsids
00:24:04
have no additional holes and today
00:24:08
they're represented by the turtles and
00:24:10
there are no unequivocal
00:24:11
carboniferous forms they may have been
00:24:13
there but they haven't found them yet
00:24:16
the diopsids have two holes
00:24:19
in the skull and they're represented
00:24:21
today by birds snakes
00:24:23
crocodiles and lizards and also were
00:24:25
represented by
00:24:26
the dinosaurs the synapsids
00:24:30
have a single hole and today
00:24:33
this is representative of
00:24:36
all the mammals including us we're all
00:24:40
synapsids
00:24:43
and synapses reptiles first appear
00:24:47
in the latter part of the carboniferous
00:24:51
so in terms of taking our ancestry back
00:24:55
through geologic time
00:24:58
our particular type of skull can be
00:25:00
found
00:25:02
in these animals
00:25:05
so they one of them or something like
00:25:08
them
00:25:09
was the base of the family tree
00:25:13
that eventually includes the mammals and
00:25:16
us
00:25:20
so these earliest known synapses appear
00:25:23
toward the end of the carboniferous
00:25:26
but very important
00:25:29
they're also they have to contend with
00:25:32
some big
00:25:32
amphibians early ops
00:25:36
was the biggest about six feet long or
00:25:39
so
00:25:39
and uh mouthful of big teeth this
00:25:43
was an animal that probably fed
00:25:45
primarily on fish
00:25:47
although it probably would have snapped
00:25:50
up a little
00:25:51
reptile if one got in its way it had
00:25:54
a pretty nasty set of teeth
00:26:00
so it was it was the prime predator
00:26:03
of the day big amphibian
00:26:10
now one of the characteristics of the
00:26:11
carboniferous
00:26:13
is the atmosphere was different from the
00:26:16
atmosphere
00:26:17
almost any other time in the earth's
00:26:19
history
00:26:21
the oxygen levels were as high as
00:26:24
possibly 35 percent
00:26:26
compared today with our 21 that we have
00:26:35
and this is probably a consequence
00:26:38
of the immense amount of plant growth
00:26:42
that had developed
00:26:45
plants photosynthesize taking
00:26:49
energy from the sun and carbon dioxide
00:26:51
and water
00:26:52
and using the energy of the sun they
00:26:55
photosynthesize and
00:26:57
as a part of the process they make
00:27:00
molecular sugar and they release oxygen
00:27:05
so photosynthesis releases oxygen
00:27:09
and so carbon dioxide is pulled
00:27:13
into the plants oxygen
00:27:16
is released and so that's what's going
00:27:19
on with
00:27:20
these great forests they're bringing
00:27:21
carbon dioxide out of the atmosphere
00:27:24
and they are releasing oxygen sometimes
00:27:27
you see
00:27:28
someone say that they pulled the carbon
00:27:30
dioxide out and thereby
00:27:32
increased the oxygen and that's not
00:27:35
really true because
00:27:37
today carbon dioxide is about four
00:27:40
hundredths of a percent
00:27:41
of the atmosphere oxygen about 21
00:27:45
you could pull all the carbon dioxide
00:27:46
today out of the atmosphere
00:27:48
it wouldn't really affect the amount of
00:27:50
oxygen we have
00:27:52
but the plants were also not only
00:27:56
taking carbon dioxide out they were
00:27:58
putting oxygen back
00:28:00
into the atmosphere
00:28:03
today there seems to be a fairly good
00:28:07
balance between the amount of oxygen
00:28:10
that
00:28:10
is released by photosynthesis
00:28:13
and the amount that is consumed by
00:28:16
respiration by both the plants
00:28:18
and the animals and this is true both
00:28:21
for
00:28:21
the non-marine the terrestrial
00:28:25
environment as well as the marine
00:28:28
environment
00:28:30
and
00:28:34
so that respiration
00:28:37
part of it is plants but also part of it
00:28:39
is animals
00:28:42
well in the carboniferous
00:28:46
we have an awful lot of plants and we
00:28:48
don't have that many animals
00:28:50
there's not that much that will draw the
00:28:53
oxygen
00:28:54
out of the atmosphere that's being
00:28:56
produced by photosynthesis
00:28:59
and so as a result we have this
00:29:02
oxygen level that's about 35
00:29:06
of the atmosphere compared with the 21
00:29:09
that we have today
00:29:14
and this allowed for some rather
00:29:16
remarkable
00:29:17
insects
00:29:20
this is a fossil dragonfly and it's
00:29:23
about
00:29:24
30 inches across it's two and a half
00:29:26
feet
00:29:28
that is one big bug
00:29:31
and the dragonflies weren't the only big
00:29:33
things
00:29:35
cockroaches have been found that were
00:29:37
also quite big
00:29:39
i don't know how many of you have had
00:29:40
the experience of turning on the light
00:29:43
and seeing cockroaches scuttle off the
00:29:45
kitchen floor headed for the dark
00:29:46
corners
00:29:48
but we spent several years living in
00:29:50
houston in the 90s and
00:29:51
yes this is something we didn't see on
00:29:53
occasion
00:29:55
i can only imagine the horror that
00:29:58
one would feel if you turned on the
00:30:01
light and
00:30:01
cockroaches the size of bedroom slippers
00:30:04
were scuttling about the floor
00:30:06
good lord don't even think about that
00:30:11
and then wait those look like
00:30:15
tire tracks in carboniferous
00:30:20
rock
00:30:23
what do we have is is this evidence of
00:30:26
ancient aliens that visited the earth
00:30:31
well actually no although the
00:30:34
organisms that produced them is about as
00:30:37
alien as you can get
00:30:41
it was a giant millipede or
00:30:43
centipede-like
00:30:44
animal and these things
00:30:48
were up to eight feet long and several
00:30:51
feet across
00:30:55
if i saw one of these in the backyard i
00:30:58
don't think i've got enough bug spray
00:31:00
in the house or anywhere else to
00:31:04
deal with it they're pretty formidable
00:31:09
so why did the insects get this big
00:31:14
well insect respiration breathing
00:31:18
they don't have lungs they don't pump
00:31:19
the air through the air just
00:31:21
circulates through it goes through
00:31:23
little holes in their side called
00:31:25
spiracles
00:31:26
and then enters tubes called trachea
00:31:29
they get smaller and smaller and finally
00:31:31
diffuse out in
00:31:32
to the insects body so it's just a
00:31:35
simple diffusion of air
00:31:37
from the atmosphere through this tube
00:31:39
system
00:31:40
and the tube system is is pretty small
00:31:44
so if the bug gets bigger and the tube
00:31:48
system
00:31:49
stays the same size it's not going to
00:31:51
get enough oxygen to support it
00:31:53
but in a world where there is a lot of
00:31:56
excess oxygen
00:31:57
already in the atmosphere it allows
00:32:01
the insects to get big and that's
00:32:03
probably the primary reason
00:32:05
we see these really giant insects
00:32:08
in the carboniferous
00:32:12
so a big change from our world of today
00:32:15
a lot more oxygen then
00:32:17
i'm not sure how dangerous that
00:32:20
level of oxygen would be to us today
00:32:23
oxygen is
00:32:24
toxic and
00:32:27
we'd probably adapt to 35 oxygen
00:32:31
but i know that when i was an aquanaut
00:32:33
years ago
00:32:35
one of the great concerns was keeping
00:32:36
the oxygen level
00:32:38
down at a level that we weren't getting
00:32:41
too much oxygen in our breathing because
00:32:43
it could cause all kinds of problems
00:32:48
one of the features of the geological
00:32:52
features
00:32:54
of the carboniferous rock is something
00:32:56
geologists call
00:32:57
cyclothyms and cyclothems
00:33:01
are cycles of repeated cycle of
00:33:05
rock type in the sediment
00:33:09
and this would be a fairly typical one
00:33:11
it starts at the bottom
00:33:12
with a marine mudstone that passes
00:33:14
upwards into a
00:33:16
sandstone and formed on a shoreline and
00:33:18
sitting on top of that some non-marine
00:33:21
muddy sandstones maybe some fresh water
00:33:24
limestone mudstone above that then coal
00:33:29
and sitting directly on the coal is
00:33:31
marine mudstone
00:33:33
that eventually might pass to marine
00:33:35
limestones up
00:33:37
further up section and then back to
00:33:39
marine mudstone and then
00:33:41
upwards into a shoreline sandstone a
00:33:44
cycle
00:33:46
that's repeated in the rocks
00:33:55
and so what we're really seeing in terms
00:33:57
of the environment is a shallowing
00:34:00
of the sea until we get shoreline
00:34:02
deposits
00:34:04
and then a shoreline deposits pass into
00:34:06
non-marine
00:34:08
and from the non-marine we end up with a
00:34:12
a swamp where coal is produced
00:34:15
and then the sea comes in over the top
00:34:17
of that
00:34:19
and continues to deepen until finally it
00:34:22
starts to shallow and then we start
00:34:25
generating the cycle all over again
00:34:29
and let me back up one
00:34:33
you'll note that we have this
00:34:37
change from the non-marine swamp
00:34:41
jumps into marine deposits
00:34:44
immediately at the top and i think this
00:34:47
is fairly
00:34:48
typical of shorelines that are
00:34:50
retreating
00:34:51
for example this is the east coast and
00:34:54
uh the sea is encroaching there's
00:34:57
not that much sand that's available to
00:35:00
the system because it's being trapped in
00:35:02
the rivers
00:35:03
so without sand getting out into the
00:35:05
marine environment
00:35:07
the bit of sand that you've got is
00:35:09
pushed by the waves up into beaches and
00:35:11
barrier islands and then
00:35:12
as sea level rises these just move
00:35:14
forward well behind
00:35:17
those beaches are marshes and this is
00:35:19
where the coal would form
00:35:21
and then the berry island sands would
00:35:23
move right on across
00:35:25
over the top of that and you start
00:35:27
getting
00:35:28
marine muds deposited on top of those
00:35:31
old coley deposits
00:35:35
so that is the character of a cycle of
00:35:38
them
00:35:38
a pattern of shallowing
00:35:42
and going from marine to non-marine
00:35:45
back and forth and back and forth it
00:35:48
isn't just carboniferous rocks that show
00:35:50
this
00:35:50
um this kind of pattern i i have found
00:35:54
basically in shallow open coast deposits
00:35:57
all around the world and it is a very
00:36:01
common signature but it's particularly
00:36:03
common
00:36:03
and well developed in the carboniferous
00:36:09
so this is the pattern shallowing then
00:36:11
non-marine
00:36:12
then the coal marine incursion over the
00:36:16
top of that that gets deeper
00:36:18
and then shallowing back up again so
00:36:21
it's a change
00:36:22
you could call it a change in sea level
00:36:24
in a sense
00:36:28
for those of you who sat through the
00:36:31
talk
00:36:31
on uh that i gave earlier
00:36:35
on climate through time we talked a bit
00:36:38
about
00:36:38
malinkovic cycles these cycles that are
00:36:41
caused by
00:36:42
variations in the earth's orbit or the
00:36:44
tilt
00:36:45
of its spin axis and
00:36:52
we noted that there was a real profound
00:36:56
link between particularly this
00:36:58
eccentricity curve
00:37:00
and the episodes of glaciation shown
00:37:03
here in blue and interglacial
00:37:06
interglaciation joan and brown
00:37:09
but there's a seems to be a real
00:37:12
consistent pattern
00:37:14
to that in our recent past
00:37:17
in fact a part of the world were
00:37:19
probably still
00:37:20
part of with this pattern
00:37:23
we just happen to be stuck at the top of
00:37:26
one of these things now
00:37:27
there's no reason to think that that
00:37:29
pattern is not going to continue
00:37:31
as it has in the past
00:37:34
this is a fairly recent study
00:37:38
about five years ago that was looking at
00:37:41
observed cycles
00:37:42
in the rocks which are shown here in red
00:37:47
and predicted malencovich cycles which
00:37:50
are shown with the dashed blue line
00:37:53
and again there is a pretty remarkable
00:37:56
correspondence between what they found
00:37:58
it looks like
00:37:59
these molecular cycles that have
00:38:00
dominated our pleistocene world were
00:38:04
also there dominating some of the
00:38:07
carboniferous world
00:38:08
as well
00:38:14
which takes us to another subject and
00:38:17
that is the origin
00:38:18
of coal because we had
00:38:22
these immense swamps where trees
00:38:26
plants were dying getting buried in the
00:38:29
water
00:38:30
and they were not decomposing today wood
00:38:34
that gets into the water
00:38:35
their bacteria and their fungi that
00:38:38
consume the wood and basically it
00:38:41
doesn't really form
00:38:42
coal today
00:38:46
but things like this fungus
00:38:49
hadn't evolved yet this came in probably
00:38:53
about another 100 million years later
00:38:56
and it then
00:38:59
would decompose the wood but in the
00:39:02
carboniferous there's
00:39:03
really not much that decomposes that
00:39:06
wood so all that carbon
00:39:08
that is carried down into these swamps
00:39:11
is preserved in a form of peat
00:39:17
which is probably everybody's familiar
00:39:19
with it from garden work
00:39:22
just a black heavy soil most of the peat
00:39:25
today comes from
00:39:27
mosses that hadn't yet involved
00:39:30
in the carboniferous so all of the peat
00:39:33
from the carboniferous was from these
00:39:35
woody plants that had died and decayed
00:39:38
in these swamps
00:39:41
and this was in a zone that was
00:39:44
um today it would be considered between
00:39:48
the
00:39:48
30 degrees north and 30 degrees south
00:39:50
and basically
00:39:52
what we have here north america we have
00:39:55
europe
00:39:57
china all forming within this zone
00:40:02
where you might call it the peat zone
00:40:06
so lots of carbon being sequestered into
00:40:10
the sediment and that carbon
00:40:13
in the form of peat when it's put under
00:40:15
heat and pressure
00:40:17
is converted to coal
00:40:21
it goes through a phase early on of
00:40:23
lignite
00:40:25
lignite is brownish it will burn but
00:40:28
lots of impurities a lot of water
00:40:30
still within it it's not a very
00:40:33
efficient
00:40:33
fuel but if it gets
00:40:36
compressed a bit more and put under
00:40:39
pressure
00:40:40
a little bit of temperature it creates
00:40:43
common coal
00:40:44
bituminous coal and if you take
00:40:48
a coal and put it under a lot of
00:40:51
pressure
00:40:52
to the point that you're making a
00:40:53
metamorphic rock out of it
00:40:55
you get a raucous nearly pure carbon
00:40:58
anthracite
00:40:59
sort of the the prime coal
00:41:02
of of them all
00:41:07
and if you took this anthracite
00:41:12
and put it under a whole lot more
00:41:14
pressure
00:41:16
get something else
00:41:20
so if you can figure out a cheap way to
00:41:22
convert
00:41:23
coal into diamonds let me know
00:41:28
well how it was done how it was
00:41:30
converted to anthracite
00:41:32
and the better quality coal
00:41:35
essentially came from the mountain
00:41:36
building and the compression and the
00:41:38
pressures that were divided as those two
00:41:40
continents
00:41:41
mash together in the latter part of the
00:41:44
carboniferous and
00:41:46
later
00:41:49
coal has been utilized
00:41:53
for centuries the romans used coal
00:41:57
and one of the early uses in china was
00:41:59
as a carving material
00:42:01
which is kind of cool
00:42:04
in great britain there are exposed
00:42:07
carboniferous rocks
00:42:09
and that are exposed at the surface and
00:42:12
are just below the surface covered by
00:42:15
younger rocks
00:42:18
quite a bit of it and you can see
00:42:21
there's a real correspondence between
00:42:24
the upcrops of carboniferous rocks
00:42:28
and the coal fields of great britain
00:42:31
great britain had a lot of carboniferous
00:42:33
coal
00:42:34
and so it was not an accident that it
00:42:37
was really the first nation to move
00:42:40
into the industrial world
00:42:45
with the industrial revolution the early
00:42:48
coal mines
00:42:50
were not a really healthy place to be
00:42:55
and one of the strangest things about
00:42:57
some of them
00:42:58
is that they are very very low
00:43:02
designed specifically for children to
00:43:06
move the coal
00:43:07
out i've seen this in spain
00:43:10
and it was it was heartbreaking quite
00:43:12
honestly
00:43:13
to see this little three foot added
00:43:16
going off and
00:43:17
that kids would have to go in and
00:43:21
work to bring the coal out
00:43:25
coal mines commonly flooded because they
00:43:28
were
00:43:29
hollow and low so water would seek them
00:43:32
out
00:43:33
and so that was a constant problem with
00:43:35
these british coal fields
00:43:38
and so the first steam engines were
00:43:40
developed
00:43:42
in order to get the water out of the
00:43:44
mines that was her primary function
00:43:47
but once you develop a steam engine fuel
00:43:50
it with coal
00:43:51
you've got something that can do all
00:43:54
kinds of things in terms of manufacture
00:43:57
and this is the origins of the
00:44:01
industrial revolution that began
00:44:03
probably in the
00:44:04
16 maybe late 1700s in
00:44:09
england and uh carried on into
00:44:12
the early 1800s
00:44:17
one of the consequences was a railroad
00:44:20
trains that ran on coal
00:44:24
in this country in 1830
00:44:28
there were 23 miles of railway
00:44:32
by 1850 there were more than
00:44:36
9 000 railway miles and they were
00:44:39
growing fast
00:44:40
and notice that most of them are up in
00:44:43
the northern states
00:44:47
and this is a reflection i think of the
00:44:50
fact that we have
00:44:51
lots of carboniferous coal high-quality
00:44:54
coal
00:44:55
that is in this part of the country
00:44:59
and was fueling the industry and the
00:45:02
industrial revolution
00:45:04
that was occurring within the united
00:45:06
states following that
00:45:08
in great britain
00:45:16
was the american civil war
00:45:19
a legacy of the carboniferous
00:45:23
well i suspect my historian friends
00:45:25
would probably tell me i should stick to
00:45:27
rocks
00:45:28
but i look at that map but the
00:45:30
distribution
00:45:32
of carboniferous coal high quality coal
00:45:35
and you see it's mostly in the northern
00:45:38
states
00:45:38
and the proximity of that coal to
00:45:41
industry
00:45:42
to the development of industry
00:45:45
and then with the industry population
00:45:48
centers
00:45:49
the north developed an industrial base
00:45:55
that was quite different from the south
00:45:58
which
00:45:59
didn't have that much coal didn't have
00:46:00
that much industry and remained pretty
00:46:02
much
00:46:03
an agrarian society
00:46:06
with an economy that was fueled by
00:46:09
cotton
00:46:10
and slave labor
00:46:13
and so i don't know
00:46:17
maybe the carboniferous did
00:46:20
have an impact on the division
00:46:23
of the american civil war the division
00:46:27
of north
00:46:28
and south
00:46:31
so i don't know if we didn't have the
00:46:33
industrial revolution
00:46:36
whether we would have a city like this
00:46:39
i'm guessing there would be a city
00:46:42
but i suspect that without the
00:46:44
industrial revolution
00:46:46
that's largely based on carboniferous
00:46:48
coal
00:46:50
it wouldn't look like this
00:46:55
as we get to the end of the
00:46:56
carboniferous the swamps are
00:46:59
disappearing
00:47:01
and the carbon
00:47:05
that has been taken out of the
00:47:06
atmosphere by the plants
00:47:09
is starting it's having an effect it's
00:47:12
chilling effect
00:47:13
and so we're seeing a collapse
00:47:16
of the rain forest in the late
00:47:19
carboniferous
00:47:22
and with that we have some extinctions
00:47:26
and we move from the carboniferous
00:47:29
into the succeeding period the permian
00:47:34
a permian is a time as
00:47:37
a world dominated by large lizards like
00:47:41
these sailback lizards if you haven't
00:47:43
ever had a plastic dinosaur
00:47:46
set i'm sure you've seen these lizards
00:47:51
in them they're not dinosaurs they're
00:47:54
actually
00:47:54
a synapsid reptile which means they are
00:47:57
members
00:47:58
of the mammalian family tree they
00:48:01
are the descendants of those synapsid
00:48:05
reptiles that developed in the late
00:48:08
carboniferous
00:48:12
some of them may have been hairy but
00:48:14
they still laid eggs there was still
00:48:16
there were still reptiles
00:48:20
the permian had two significant
00:48:23
extinctions both
00:48:25
caused probably certainly associated in
00:48:28
time
00:48:29
with flood basalts major outpourings of
00:48:32
lava on the surface of the earth
00:48:37
and the second one of these at 250
00:48:39
million years
00:48:40
is called the great dying
00:48:44
and it was the greatest extinction event
00:48:48
in the history of the earth
00:48:50
96 of the marine species
00:48:54
died and 70 of the land species
00:48:58
major major catastrophe and greater than
00:49:01
anything else we have seen
00:49:04
so why that particular severity
00:49:10
well we have had a number of
00:49:14
basalt eruptions like that at the time
00:49:18
and they caused extinctions but nothing
00:49:20
like that why was this one
00:49:22
so much difference why the great
00:49:25
death of the marine
00:49:29
organ organisms and the answer
00:49:33
is that in siberia where
00:49:36
this eruption occurred
00:49:39
there were thick coal seams probably
00:49:42
not too different from this one in
00:49:45
montana
00:49:46
and when lava comes through that
00:49:50
volcanic action comes through that it
00:49:52
burns that coal
00:49:55
this is a paper that just came out this
00:49:57
year
00:49:59
but looking at volcanic ash from those
00:50:01
eruptions
00:50:02
they find lots of little pieces of coal
00:50:06
really documenting the fact that the
00:50:08
coal was there
00:50:09
and they're in abundance and the burning
00:50:12
of it probably
00:50:13
dumped a huge amount of carbon dioxide
00:50:17
into the atmosphere and that carbon
00:50:19
dioxide
00:50:22
would cause an acidification of the
00:50:25
ocean probably
00:50:27
greater than anything we have seen which
00:50:29
can account for this
00:50:31
tremendous die off in the oceans
00:50:34
and that particular event set the stage
00:50:39
then
00:50:40
the big diopsid lizards are gone there's
00:50:44
still
00:50:45
um diopsid reptiles around the circle is
00:50:48
around
00:50:49
one there looking at the two little
00:50:51
dinosaurs that have just
00:50:54
appeared on the scene around 230 million
00:50:56
years ago
00:50:57
but that little reptile
00:51:00
by another 20 million years or so
00:51:04
may well be producing its offspring
00:51:06
producing
00:51:07
or being the first mammals
00:51:13
so carboniferous deposits fueled the
00:51:16
industrial revolution
00:51:19
and today they may carry on as a threat
00:51:22
to our way of life coal
00:51:26
emits more carbon dioxide per
00:51:30
amount of energy release
00:51:33
than any of the other fuels so it's
00:51:36
particularly i wouldn't call it dirty
00:51:38
it's just
00:51:38
very rich in carbon dioxide
00:51:42
and carbon dioxide as we noticed and
00:51:45
noted in the other talks that i gave
00:51:48
is clearly linked to temperature in this
00:51:51
this ice core
00:51:52
from antarctic the red line above
00:51:56
shows the inferred temperatures from
00:51:59
oxygen isotope data
00:52:01
and the curve down below the blue one
00:52:04
shows
00:52:04
carbon dioxide levels as indicated from
00:52:08
bubbles within the ice and there's
00:52:11
a real solid comparison between the two
00:52:16
and carbon dioxide has been going up and
00:52:19
as
00:52:19
carbon dioxide has been going up in our
00:52:21
modern world
00:52:23
so has the global temperature again
00:52:26
looking like there's a very distinct
00:52:29
connection between carbon dioxide
00:52:32
and temperature
00:52:36
coal production has
00:52:39
almost doubled in
00:52:42
this century so far
00:52:46
and the consumption has gone up
00:52:50
equally basically in asia
00:52:54
europe has declined a bit north america
00:52:56
is just about same
00:52:58
through this period of time but asia
00:53:00
coal
00:53:01
has become the major fuel
00:53:04
it looks like and
00:53:09
this putting carbon dioxide into the
00:53:11
atmosphere and warming
00:53:12
the atmosphere has one effect that i
00:53:15
want to
00:53:16
sort of focus on because i think it's
00:53:18
it's one of the most immediate
00:53:19
and scary effects of burning all that
00:53:23
coal
00:53:23
that i can think of
00:53:27
we've heard a lot about storms this year
00:53:29
there have been a bunch of them
00:53:32
including one magnitude 5 at the very
00:53:35
end
00:53:36
in the gulf of mexico and the big deal
00:53:39
with
00:53:40
these kinds of hurricanes and typhoons
00:53:43
it's not so much the wind that's
00:53:46
associated about the rise in water level
00:53:49
that's
00:53:49
carried by the storm of basically
00:53:52
bringing water into the shore and
00:53:55
flooding
00:53:56
the coastal areas with a lot of water in
00:53:58
a relatively
00:53:59
short period of time you see that new
00:54:02
orleans
00:54:04
2005 prime example of what can happen
00:54:10
there is a clear-cut link i think
00:54:14
between the water temperature
00:54:18
in the ocean and the power of tropical
00:54:21
storms
00:54:22
and i think you can see that pretty
00:54:24
clearly from this graph that shows storm
00:54:27
power
00:54:28
and sea surface temperatures over
00:54:31
a series of decades starting in 1950
00:54:36
i'm talking now about the storms that
00:54:38
form in the tropics the hurricanes the
00:54:41
typhoons
00:54:41
cyclones whatever you call them in the
00:54:44
pacific
00:54:49
and this source says that since 1979 if
00:54:52
you look at the strongest
00:54:53
hurricanes or typhoons and this is
00:54:56
several years ago
00:55:00
of the seven five of them formed in this
00:55:03
last
00:55:04
decade
00:55:08
and this is a diagram that i made just
00:55:11
looking at the number of magnitude 5
00:55:13
hurricanes through
00:55:15
the period of time from 1920 to 2020
00:55:18
the last hundred years and in the first
00:55:21
80 years we had 13 magnitude 5
00:55:25
hurricanes since 2000 in the last 20
00:55:28
years we've had
00:55:29
an additional 13. there's
00:55:32
doesn't seem to be much question that we
00:55:35
are getting
00:55:36
more big storms today than we had in the
00:55:39
past
00:55:40
and this almost certainly relates to
00:55:44
the warming of the oceans
00:55:49
so in the us there we've got problems
00:55:54
flooding from high tides has doubled in
00:55:56
just 30 years
00:55:59
these are essentially storm floods new
00:56:02
york city 50
00:56:03
of it's at risk and the plans
00:56:07
are it's going to take about 4 billion
00:56:10
dollars
00:56:10
to protect the city which is a lot of
00:56:14
money
00:56:15
and miami may not be protectable
00:56:19
in a any kind of an economic sense
00:56:23
there are some that suggest this city is
00:56:26
just going to have to be abandoned
00:56:29
and this is probably true new orleans as
00:56:31
well but the place where
00:56:33
i have the biggest concern is actually
00:56:36
in asia
00:56:38
in asia they have something that they
00:56:40
call the l e c z
00:56:42
the low elevation coastal zone this is
00:56:45
the land that's lower than about 30 feet
00:56:48
above
00:56:48
sea level or 10 meters above sea level
00:56:52
and a huge number of people live in that
00:56:55
zone
00:56:55
hundreds of millions of people in that
00:56:58
zone many of them already on deltas that
00:57:00
are subsiding
00:57:02
that are also that contributes to the
00:57:04
problem even more
00:57:06
and they are particularly vulnerable
00:57:10
to large typhoons
00:57:14
and these can just be absolutely
00:57:17
devastating
00:57:19
in their flooding effects and the floods
00:57:23
really are what takes a toll on humans
00:57:26
the number of deaths hundreds of
00:57:29
thousands of people
00:57:30
died and
00:57:33
it looks like to me that we've got a
00:57:37
recipe for
00:57:38
horrible disasters take
00:57:41
you want the recipe it's one global sea
00:57:43
level rise which is
00:57:45
not very high and you add that to
00:57:49
actively subsiding
00:57:50
highly populated sea coasts and mix in
00:57:53
more
00:57:54
violent storms due to warmer water
00:57:57
and add a handful of devastating storm
00:57:59
surges and
00:58:01
i think you can't get around the fact
00:58:05
that this century is going to see some
00:58:08
really serious rearrangement
00:58:12
especially in asia coastal population
00:58:15
centers
00:58:16
um very much an ill-wanted
00:58:19
legacy of the carboniferous
00:58:23
but there is with a silvery lining of
00:58:28
sorts and that is there's still a lot of
00:58:30
coal available
00:58:31
and we may someday find a way to utilize
00:58:34
it
00:58:35
without this great
00:58:38
problem with the carbon dioxide and it's
00:58:42
kind of money in the bank
00:58:43
it's it's maybe we'll never have to use
00:58:46
it
00:58:46
but sometime in the distant future
00:58:50
that may pull us through some crisis
00:58:53
or another and so with that
00:58:58
i wish you all wonderful holiday season
00:59:02
stay safe
