It is my pleasure to be here with you.
You teachers, you're heroes, okay?
Our daughters – we have one daughter who is a schoolteacher,
one daughter who is a graduate student and will teach someday.
And I wanna thank you for spending an hour with me,
tonight, or 45 minutes, or whatever we do.
I am hopeful that I am about to be sharing my screen with you,
and I am hopeful that you are seeing
a picture of me bungee-jumping for science.
If you're not, I hope that Bruce will yell at me really fast.
But if you're seeing my screen, in addition,
I will, in the course of the discussion here,
I will scribble on things.
So you will see me scribble on things,
so I hope you just saw me scribble on me bungee-jumping,
and that will work.
So, at any rate, I am going to launch into a talk;
if there's any problem,
please stop me or yell at me or something like that,
and we'll see where we can go from there.
But this is a –
there is nothing in climate science that's really hard,
but there's a lot in climate science that's really long.
And it gets complicated, because there are so many pieces to it.
And I have sort of the bullet points right here.
If we had a few hours – I'd love to have a few hours –
but we could show you the very high scientific confidence
that the world is warming, that we are the main cause,
primarily from CO2. That the changes that we face,
if we continue on the path we're on,
will be large compared to the changes
that we have faced so far.
That this will cause winners and losers,
but that the losers grow to grossly dominate.
That we will be better off, in money,
to deal with this than to ignore it.
That there are ethical issues:
the people that win are mostly wealthy people in cold places,
and the people that lose are mostly poor people
in warm places and people that haven't been born, yet.
And that when we respond to this,
we can improve our economy,
we get more jobs, we get greater national security,
and we can be more true to the golden rule,
for everyone, forever.
Okay, so that's the story of climate change,
if you put the whole thing together,
but we can't do that in an hour. Not even close, okay?
So, what we're going to do is try to get somewhere in an hour, here
and see if we can move forward, here.
You will hear, "Isn't the science uncertain?"
Yes, this is science:
science always has uncertainties,
that's a guarantee.
But ignoring the science, the uncertainty makes it worse,
and the reason is that the uncertainties are mostly
on what you would say is the bad sad.
And I'll through this. There is a most-likely future;
things may be a little better than that,
they may be a little worse,
they may be a lot worse, for very good physical reasons.
This is not made up; this is actually real.
And you probably know the common-sense argument
why the uncertainties will be mostly on the bad side.
It's easier to break something than it is to build it.
To try to build a house, you don't just need a hammer,
you need all sorts of tools and materials and –
but you can break the house with a wrecking ball.
It's much easier to break things than it is to build them.
Simply cranking up CO2 by burning lots of fossil fuels
is very, very unlikely to turn the earth into Eden.
But it might break things, because CO2 –
getting it right would make getting a lot of things right,
and CO2 is only one thing.
And so, the uncertainties are mostly on the bad side.
And I'm going to walk you through ice cores
and the history of climate, to show you that,
and then come back to the good news
that we actually can make ourselves better-off
if we deal with this.
So, let me take you to Greenland –
this is a picture of coastal Greenland.
If you ever get the chance to go,
it's such a wonderful place, you just have no idea.
It's truly fantastic. This corridor glacier
in east Greenland – this is south Greenland.
The ice used to be bigger than it is now,
so 100 years ago or so, the ice went all the way
down to near the bottom of this picture,
and you can see the deposits.
But even though it's melting back,
it's still very, very pretty.
You know, it's – these are caribou, reindeer;
they're up on the ice,
because they're trying to get away from the mosquitoes
which are down on the tundra. If you do go to Greenland
and go down on the tundra, it can be a little bit buggy.
We're in the middle of the ice sheet;
we are 200 miles from the nearest rock,
and this fox came trotting into camp,
one of the more remarkable things in my life.
This is a picture of a fine day in Greenland.
We had been there for a month, so the USA
Today over here on the side was not exactly current.
However, you'll notice, there over on the other side,
that the USA Today was perfectly functional.
You will notice that this is a good day in Greenland,
because there's only a small amount of snow on the seat.
Now, if you wish to see a bad day in Greenland,
there is, as we say, more snow on the seat.
So, Greenland is an interesting place to work:
we are in the middle of the ice sheet,
we're 200 miles from the nearest rock,
and we're on 2 miles of ice here, okay?
So, it's fun. This is pictures of the Fourth of July.
We were having a party, playing volleyball
on two miles of ice,
and this is the famous scientist,
Eric Salsman, who's in the snow trap.
Picture on the right, after a month, you know,
you might decide that your socks
are taking on a character of their own,
and so, this is freeze-drying laundry.
So, it's a fascinating thing to live on the ice sheet,
and I'm glad I've done it.
I'm gonna take you right into the science.
You're up there in Greenland, and a storm comes,
and the wind blows, and it howls,
and the drift goes through everything.
And after it's done,
if you look at the surface of the snow, it's fairly smooth.
There are snowdrifts, but it's a fairly smooth-looking surface.
The wind has packed the snow down,
and you can see it there in this picture.
But then what happens?
The sun comes out during the day,
and it shines brightly; it doesn't melt.
We're at a place that, in a typical year,
never gets up to freezing, but it does warm the snow.
And then at night, the sun gets low;
this is the midnight snow in the middle of Greenland.
And as the sun gets low, the air cools off,
and it goes down to minus-30, and you get a fog.
And the fog grows frost. And if you've ever gotten up
in a dewy morning or a frosty morning,
Greenland gets frost that puts those to shame.
And so, this is a frost in Greenland,
and if you remember the surface I showed you a little bit ago,
now, if you look down at the bottom of the picture,
this is really serious frost
with lots of lumps and bumps in it.
And the frost grows on everything.
So, here is a picture of the frost,
in our upper-left corner,
there; this is frost growing on the volleyball net,
and this is a lens cap down here next to the frost.
And this is a student who is working with me,
now the chair of geography at Berkeley, Kurt Cuffey,
this is his skiing tracks through the frost.
It's a beautiful thing, okay?
So, we're watching the surface of Greenland do things.
Now, if I take my Swiss army knife,
which you can see over there in the far-right,
so, over here is the Swiss army knife,
and if I take the Swiss army knife
and I cut out a little block of snow, what do we see?
Down below is the snow that the wind packed,
and here is snow that actually has sublimated.
Some of it has gone up into the air, and then at night,
it has come down to make the frost on top.
And so, we have taken a wind-packed
little piece of snow,
and turned it into this big fuzzy thing.
And you actually can watch this happen from space,
by using microwaves, and –
it's just a wonderful thing to watch happen.
And that will get buried.
So, more snow falls after this snow,
and now what are we gonna do.
Down here in the lower-right here,
this is Joan Fitzpatrick,
the famous scientist from the United States Geological Survey.
This is me without the shirt.
And we're shoveling, and we have dug two holes,
a big hole that we're in and another big hole over here.
We're gonna put a board on the hole I'm in,
we're gonna cover up Joan and me –
Joan is cutting stairs, so I can get out.
And we put a board on this one, and we leave this one open.
And then what happens, the sun shines in,
and then it's going to shine through this wall that you see.
And you'll be in the dark sitting in here
where I am in my no-shirt,
and we will see the layers in this wall.
So, we're gonna climb down in this hole,
and then pull the board over the top,
and then we're gonna see what we see.
And this is what we see: snow is blue,
and it is blue, essentially, for the same reason that water is blue.
And what we're looking at is a little piece,
here, that is about six inches on a side.
And you remember that frost that grew on the surface,
it is low in density, it is coarse grain,
and the light shines through it easily.
So, this is one of those frost complexes.
This is snow that the wind packed,
so this had wind on it,
and it's a very funky-looking dark thing.
This is another frost from before that;
you can see where the wind
scoured into one of these surface frosts.
One year, we dug up a snow mobile track –
we can recognize these things. But here are the layers
that form during the summer in Greenland.
Now, if we go and back up a little,
which we're going to do next, what do we do?
These are the whole pit wall, sitting in here.
That previous picture that we just saw
is the little white square over on the right.
So that previous picture you just looked at
is this little thing over there –
sorry, I made it go away –
it's this little thing over there,
and so, you can see where it is.
And now what you see, these are the layers that accumulated
during the winter when there wasn't sun.
These are the layers that accumulated during the summer,
when the sun was warming the surface to evaporate,
so that it could come back down as frost.
Here's the previous winter. As you go down, it gets darker,
but you can see all the funky layers of the previous summer.
So, what do you have here?
Here is a summer, and here is a winter,
and here is a summer,
and here is a winter, okay? And there's two meters.
But this will get squeezed by the weight of more snow,
and will become ice.
So now let's follow that. So what are we gonna do?
We build this great big drill, and it's a 100-foot-tall tower,
and it's going to drill down into the ice sheet.
And here's Katherine from Alaska,
and this big National Science Foundation-supported project.
These are the kinds of things
that are done by the ice core drillers,
who are such fantastic people, they really do great things.
Here we are, now, we're done in a secret undersnow laboratory.
Bill Campbell from University of New Hampshire,
here, is cutting an ice core;
you can see the ice core sitting there.
This particular undersnow laboratory
would make any dean or principal happy:
if your lab isn't big enough, you get a chainsaw
and you womp out a piece of the wall, and it's bigger.
Because the wall is just snow, and it's a constant minus-20,
and everybody's happy.
[Laughs] So, here are ice cores, and these are ice cores –
this one is from 1,547 meters down,
and other depths are in here.
So this is 10,000-year-old ice, something like that.
And we're sitting there waiting to be analyzed
in our secret undersnow laboratory.
And the analyses were done by people like Wanda Kapsner,
over here on the right,
and Kurt Cuffey over here on the left,
and Wanda is cutting little sections,
and Kurt is looking at a core.
And so, we did a lot of analyses there,
then we shipped them on to the US National Ice Core
Laboratory in Denver, and did more things,
and it's all fascinating.
And here, lying on its side, is a core;
1411.8 here is 1,411.8 meters down.
And 1411.9 is 1,411.9 meters down.
So, up towards the surface – it's on the side,
we lay the core on its side, to look at it.
Those layers that the sun hadn't cooked had big crystals,
they made big bubbles; the bubbles have been squeezed,
but you can still see the darker layers are the _____
ones.
And so, these layers in here are a summer, and this is a winter,
and next to it are the layers that are summer,
and next to it is another winter.
And so, here we have what was forming at the surface,
because the sun shines in the summer
and it doesn't in the winter,
and we see it preserved in the ice sheet.
And this one's from 8,400 years,
because we have counted down 8,400 of these layers.
All right, now, why should you believe me?
So, what do we do? I count, and Chris _____
counts, and Deb _____ counts, and _____
_____ counts, and Kurt Cuffey counts
– there are other things that vary from summer to winter,
and so we count in different things.
We count in isotopes, and we count in dust,
as well as counting in this way. And then we check ourselves.
In 1954, the US blew up Bikini Atoll
with a really big, really dirty atomic bomb.
The fallout from that went the whole way around the world.
It is still in the ice sheet,
and you can find the radioactive layer from that
and from a bunch of Soviet tests in the mid-'60s.
And so, we can count down to that
and see if we match that fallout.
When a big volcano erupts,
it puts a little bit of ash around the whole world.
Some of those are sufficiently distinctive chemically
that you can say, "This is Laki from Iceland.
This is Elja. This is Hekla. This is Katla. This is Vesuvius.
This is Etna," and you can actually see,
do we get the right age for that.
I will show you, in a minute,
that there have been abrupt climate changes.
And those abrupt climate changes
are not only recorded in our ice core,
they're recorded in the tree rings,
they're recorded in lake sediments.
And so, we can ask what age
do you get for those in your record,
to compare to ours in the ice core.
And we can do this on lots of different ice cores,
with different teams from different nations, and so on.
And what we ended up with is that,
for the last 11,500 years, we were good to 1 year in 100.
If I told you that I had gone 100 years,
it was 99 or 100 or 101,
and occasionally maybe 98 or 102,
but it was pretty good. We counted 110,000 years.
It was a little bit bigger errors as you got older –
in the Ice Age,
it didn't snow as much and the layers were thinner –
but you can actually go down with these a very long way.
Now, if you can count the annual layers,
and you know a little bit about the weight
squeezing snow to ice and the flow of the ice sheet,
the thickness of a layer tells you how much it snowed.
And there is a flow correction, but nonetheless,
you can get how much it snowed.
You can measure dust and sea salt
and little micrometeorites from space
and all sorts of things that fall in the ice
and are trapped there.
If you see a dirtier layer, it either is dirtier
because there was more dirt
or because there was less snow to dilute the dirt.
But if you know how much it snowed,
you know how dirty the air was.
So now you can measure dust coming through the air,
you could ask whether the amount of micrometeorites
from space changed.
And they didn't, but you can ask those questions.
If we had more time, I would walk you through
how we estimate past temperature on the ice sheet,
there are several ways, they're really wonderful,
and they actually work very well.
And in that ice, there are bubbles,
and in the bubbles are little samples of old air.
And it's the only place we know to find old air.
And they're all in there together.
So, we can learn about snowfall in Greenland –
or Antarctic if it was an Antarctic core –
temperature on the ice sheet, we can learn how much dust
and how much sea salt and how many micrometeorites
and how many volcanoes and all sorts of things,
what was the composition of the atmosphere all together, okay?
So it's just a fascinating undertaking.
Now, we're doing this on ice, but we have friends doing trees,
and doing lakes, and doing the muds on the seafloor,
and all sorts of other things. As we look further back in time,
our ability gets fuzzier, nature tends to recycle,
and so really old things are harder to find,
but we find them. And we learn so much
that you just can't possibly imagine all of it.
I teach an entire semester on this
to just introduce the topics, not even to solve them all.
But as we learn, what do we see?
When the sun changes in brightness, the climate changes.
When volcanoes block the sun with particles,
the climate changes.
If you change how reflective the surface is, the climate changes.
If you move continents around, the climate changes.
And yet, as we look through short times and long,
what we're learning, more and more,
is that the biggest control on climate,
over all of history, has been carbon dioxide.
And I'll actually show you where you can go look this up later.
I have an hour talk
that I gave to the American Geophysical Union,
that you can find online, on the biggest control knob
that walks through the history of earth's climate _____
CO2, but what we find is that CO2 has been really important.
Nature has changed CO2.
We now know that what we're doing
is more important than nature,
because we're burning it so fast.
But CO2 has mattered in the past, and it must matter.
The physics of CO2 and the air warming are physics,
and they are physics we can't get rid of,
they are physics we've known for over a century,
and they're physics that were really worked out
by the Air Force, right after World War II,
for things such as sensors on heat-seeking missiles.
If you're the Air Force, after World War II,
you knew that enemy bombers
could do horrible things to a city.
You knew that an enemy bomber would have a hot engine,
and that would make heat radiation.
And you knew that you could see that heat radiation
with the special sensor,
follow it, blow up the enemy bomber,
before they destroyed your city.
And so, they built heat-seeking missiles
such as the one that is pictured here,
so this is a heat-seeking missile being launched.
And on this, there's a little eye that looks in the infrared,
and it looks for the heat radiation, the infrared,
from the enemy bomber.
But if you use the wrong sensor, you can't see,
because CO2 is soaking up the energy.
And CO2 then gets excited,
and then it collides with oxygen or nitrogen,
and warms the air rather than letting you see.
And so, the Air Force learned what CO2 blocks
and what water vapor blocks, and what they don't.
Down in the lower-right, here, this is a satellite picture
that puts into action what the Air Force learned.
This is how much radiation is being seen,
how well you could see a target,
and this is different wavelengths.
You could think of this as different colors,
but they're all in the infrared.
The earth is warmed by the sun, radiation comes down,
the earth radiates back to space,
and this is the satellite watching the earth cool off.
And this – I'll click one,
here, if I can – this is what CO2 is blocking –
so I've put this in magenta, here.
Every day, satellites look at the earth
and they see the greenhouse effect of CO2 soaking up energy.
If we put more CO2 in the air, more energy can be blocked,
and that's the red, here.
And so, CO2 is blocking; it can block more.
It is blocking; it can block more.
People ask you,
"Why do you believe in the Greenhouse Effect?"
we can't avoid it.
It's physics, it's observed, it's proven every day.
And the piece that goes with this
is that we are putting up CO2. There's a scaling, here.
If you put out trash for the trash collector –
the typical resident of the US puts out at the curb,
for the trash collector,
something less than 1,000 pounds of trash per year.
The CO2 produced by all of the fossil fuel burning in the US,
divided by the number of people,
our share each of the CO2 from the US
is about almost 40,000 pounds per person per year.
So, think of all of the trash you throw away,
the CO2 going into the air is 40,000 pounds per person
[glitch interferes with audio]
40 times bigger, _____ almost that much.
And so, w can't avoid a warming effect of this CO2,
and we're putting up a lot.
And so when they ask, "Why do you believe in global warming?"
there's no way we can avoid global warming.
Okay, so, let me now tell you that,
if you wanna go chasing, you could search
"biggest control knob at agu" on my name,
and you will find the talk. This is also online _____ _____
_____ and a bunch of other places.
That climate has always changed, it always will change,
but CO2 has been very important,
and probably the most important thing in climate.
How do we recognize the climate changes?
Often, by seeing what they did to living things
far back in time: extinctions, and migrations,
and getting too hot for big critters
so you only have little ones, and things of that sort.
The natural CO2 changes recognized back in time,
we may make one that big, and we may be faster
than the great majority of them, okay?
So, the [glitch interferes with audio]
physics says our CO2 from our fossil fuels is a huge deal.
History says, "Yes, that's right," okay?
And you can find the talks, you can find the information,
this is a big story, it's a long story,
but eventually, that story is real.
Just as an arson investigator studies natural fires
to learn about human ones,
we who study natural climate change
learn about human climate change.
And we confirm what the physicists know,
that we're making a big change in the atmosphere,
and that will influence the climate.
Okay?
What I'm next going to do is take you away from CO2,
for about ten minutes,
and show you something that was not caused by CO2.
We climate scientists work very, very hard to find what nature
can do without CO2 – we gave to understand that.
I'm gonna walk you through that,
we'll come back to the possibility
that CO2 might do something like that,
and then we'll finish up.
So, we can do history of climate,
we learn from climate that CO2 matters a lot,
we learn from climate that other things do matter,
and let's look at one of those. So, let's go back to Greenland.
This is the cathedral at Hvalsey.
This is sitting on the side of a fjord in Greenland.
It's a beautiful Viking church.
This beautiful Viking church was used for a couple centuries,
into the early-1400s, and then it was abandoned.
And it's sitting there, in its beautiful religiosity,
on the side of the fjord, to this day.
It's one of the more meaningful places I have ever visited –
I really enjoyed being there.
This is climate records,
and allow me to walk you through this.
The first thing is, today is over on your left, okay?
Time is running backwards to what you're used to,
so today is way over there on the left.
And over on the right is 10,000 years ago, all right?
On the side, here, is temperature; warmer is up.
And these are central Greenland climate records.
And I just want you to focus on the top one up here,
labeled "temperature." There is a big arch,
and that arch, over 10,000 years,
is features of earth's orbit moving the sunlight around.
These are very slow features, but the earth nods,
and it wiggles, and those move sunshine around on the planet,
and that's part of Ice Age cycling.
So there's that big arch you see,
and then there's these wiggles.
And these wiggles are volcanoes blocking the sun,
that makes it cold,
they are the sun getting brighter and dimmer,
they are changes in ocean currents,
and maybe some other things.
One of these wiggles, right down here
sort of in the middle of this orange bar,
is the Medieval Warm Period.
That is when the Vikings settled in Greenland
and when they built that beautiful cathedral.
And then it got cold.
Most of the world is a little warm for our comfort;
a little of the world is a little cold for our comfort,
and that includes Greenland.
Greenland did not become uninhabitable;
the native people, the Inuit, survived just fine.
But it became very difficult for the bishop
to get through the sea ice to visit the cathedral,
and somewhere about here,
at the start of the Little Ice Age, the Vikings said,
"Oh, to heck with it," and they left.
And so, this was enough of a climate change
to affect people who were sort of living on the edge
and had little open boats rather than icebreakers
[glitch interferes with audio].
Now, you'll notice I didn't show you what's back here,
because I wanna do something dramatic,
so if you'll bear with me. This is a climate change.
Now, if these little things over on the left
were enough to really affect people,
this sucker is interesting. And this is real.
There's no doubt that this is real.
It was a very big climate change,
and it was very fast, okay, and it happened.
Now, this climate change over here is now
in this little tiny corner of this picture, it's this one.
And you can see that, in Greenland,
there were lots of these big climate changes
during the Ice Age,
and that it got really boring right up here,
which is when agriculture and civilization appear.
So, these were large widespread abrupt changes,
and they really mattered, and they really happened.
And they didn't – there's –
the Vikings leave with this little change _____
_____ _____ agriculture as soon as things got boring,
and so this is real.
This is back to the Greenland one,
and I happen to have the Greenland one in green,
up at the top,
and you can see this big abrupt change right here.
And this is a completely independent record,
on a completely different place – this is from Venezuela.
And essentially, when Greenland got cold, dry, and windy,
Venezuela got cold, dry, and windy.
And in fact, as we go around the world, what do we find?
We find that when Greenland's climate changed,
everybody's climate changed.
But if you raise CO2, it warms all over the world.
If this change was cold in the north gave warm in the south,
and then warm in the north gave cold in the south.
It changed different things in different places.
It's a more interesting type of climate change.
Now, it's a fascinating thing, it's real,
it happened over and over and over again,
it mattered, you know, it's just really fascinating –
I love studying this.
I will briefly walk you through what happened.
If this is too fast, I will apologize.
I would not do it this fast to the students in my class,
but you're smart people,
and if I'm too fast, we'll find you the references –
we can find these for you, as needed.
So, I apologize, in advance, for being too fast,
but let's try it, okay?
In the winter, it gets cold. Cold makes seawater contract.
As it does, it becomes more sinkable,
but it also tends to freeze – and you can freeze seawater.
And so, there's two options, as it gets cold in winter.
If the water is a little salty, it gets really cold,
it gets really dense, and it sinks.
And then, warmer water comes to replace it,
and it doesn't freeze.
If the ocean is a little fresher, it freezes.
Today, if you go to the Arctic Ocean in winter, it freezes.
If you go off of Alaska in winter, it freezes.
If you go anywhere near the Pole in winter, it freezes,
except off of Norway where it's a little salty,
and there it sinks.
And that means off of Norway in winter, it never freezes,
and it never gets below freezing,
and the British play soccer all winter,
because it's really pretty warm up there,
because you can't put frozen ocean offshore.
If you freshened that, it would freeze.
And then it would go from at the freezing point
to about 30 or 40 degrees below the freezing point,
and the British would not play soccer in winter,
because they would have North Dakota offshore, basically.
And so, there's this very interesting thing that,
if you make a little bit fresher off of Norway,
it freezes in the winter.
So, what happened in the Ice Age is,
whenever it would start to warm up,
it would melt the ice around the Norwegian Sea,
and the freshwater would run into the ocean,
and it would freeze.
And that would get ridiculously cold, okay?
Now, today, when the water sinks off of Norway,
a warm current comes from the south to replace it.
And that current comes all the way from around Antarctica,
up the surface of the Atlantic, past Brazil, across the Equator,
up as part of the Gulf Stream, splits off from the Gulf Stream,
and it goes to Norway.
And the sun shines on it off of Brazil,
and then, when it gets up to Norway,
it gives Norway Brazil's heat.
If you freeze off of Norway, it leaves Brazil its own heat,
and it gets warmer in the south
while it gets colder in the north.
And so, this seesawing and all this other stuff is related
to changes in the circulation, okay?
But suppose you make it freeze off of Norway.
It's cold there, there's no sinking,
but the wind is still blowing from the Atlantic
to the Pacific in the Trade Winds.
And water evaporates from the Atlantic,
and it goes to the Pacific [glitch interferes with audio],
and the Atlantic gets a little saltier.
And saltier is more sinkable.
And eventually, it starts sinking again,
and then that water goes south in the deep ocean,
and it goes around Antarctica, and it goes up in the Pacific,
and it mixes to the surface
and gets back with the wind blowing over Panama.
And there's this fantastic Rube Goldberg device –
no one would ever invent
this as an efficient way to make the world work, but it does.
And so, so either it sinks off of Norway
or it freezes off of Norway, and that's the tipping point.
It's a sudden change that's really startling
and really sort of frightening,
but it could happen very suddenly.
So, and this wouldn't be another Ice Age, but
– when we were learning this, it scared us. Why?
Because we're making it warm in the north Atlantic,
and Greenland is there, and Greenland can melt,
and that freshens off of Norway,
and maybe a warming world would get warmer,
but it would get cold off of Norway in the winter.
And in the Ice Age,
when it got cold off of Norway in the winter,
a drought came to where some billions of people lived.
And so, we were scared that we would melt Greenland,
freshen the north Atlantic,
freeze it, and dry out the monsoons,
and cause horrible problems for billions of people.
Now, since we learned this, a lot of science has been done,
and the science has said everything I just told you
is basically right.
We are pushing in a bad direction,
but we're highly confident that we aren't
pushing fast enough, we're not going to melt
Greenland fast enough to freshen off of Norway
fast enough to freeze it in the winter
before it gets too hot to freeze.
And so, we probably won't bring this terrible drought down
on billions of people.
In fact, the best assessments gave less than a 1 in 10 chance
of a disaster, probably much less,
but less than a 1 in 10 chance. And now, let's go back.
Global warming, CO2 makes it warm, warm influences this,
but there might be surprises,
and those surprises might be fairly bad.
A less than 10 percent chance is not 0.
And so, this is one of those things,
yes, there are uncertainties, but are they good uncertainties?
Do we find a way
that huge abrupt changes would make us happy?
It's hard to find.
Do we find a way that huge abrupt changes would scare us?
Yes, we do. Okay?
Now, think of other huge abrupt changes
that might be a little scary.
Today, most of our corn is grown in conditions
that are similar to or a little warmer
than what corn likes in the summer.
Sometimes you don't get a good crop because it's too hot;
even if it rains, it's too hot. For much of the world,
the hottest summer we've ever seen
will be considered cool by late in this century,
if we keep burning fossil fuels.
And if our crops are already heat-stressed,
will we have summers that we can't grow food easily?
Could we make it too hot for us to live in the Tropics?
Could we – you know, there are –
you can think of things that could go really wrong,
but we don't see how just turning up CO2
will make everything perfect, okay?
So, let me walk you through this.
I am a lucky person: I ride my bicycle to work,
and in the winter, I jog.
But suppose that you are one of these poor Schmoes
who has to get in your car and drive to work, all right?
Let me walk you through what a commuter faces, all right?
So, this is problems on the bottom,
and this is how likely it is to have those problems.
The most likely thing that any commuter faces
is you're gonna get stuck in traffic,
and you'll miss the traffic light,
and you'll turn on the radio, and it's not –
the Captain and Tennille is singing Muskrat Love,
and you're just
[glitch interferes with audio], right?
So, the most likely thing is a few annoyances,
but you get to work and you do your job and it's no big deal.
It is possible that you get in your car
and you drive to work and it's fantastic,
there is no traffic, and you turn on the radio,
and they're doing the Beachboys Festival
and you're just groovin',
and you get to work and you got a big smile on.
It is also possible that you get in your car,
and you drive to work,
and you sit in traffic for an hour,
because there's been an accident in front of you.
And you turn on the radio,
and they're testing the emergency broadcast system
and it's going yeeeeeee, and you're not going anywhere,
and your blood pressure is going up,
and you're really unhappy. It is also possible
that you were the person in the accident,
and you were run over by a drunk driver,
and you're badly injured or dead.
What we expect is the most likely outcome
is way on the good end of what's possible.
Now, what we do about that is we buy cars with airbags
and crumple zones and antilock brakes,
and we put on our seatbelts
and we put our kids in the kids' seats,
and we take out insurance
and we support Mothers Against Drunk Driving,
and we have traffic engineers
and we have police trying to get the drunk drivers off the road.
We put a lot of our budget into dealing with something
that we don't expect to happen,
because if it happened, it would be so catastrophic.
And this is the reality of our lives,
we deal with this all the time.
We know that the worst that could happen can be really bad,
and so we deal with that.
Now, if you take the climate story,
there is a best estimate of what we face.
It is not the end of the world – don't go out and commit
hari-kari or anything – but it causes problems.
And as I said, the whole story, if we put it all together,
is that dealing with this makes us better off.
The uncertainties are maybe the changes won't hurt us as much,
maybe they'll be slower or smaller than we think,
but maybe they'll be larger or faster.
And maybe we'll cause
that drought that hurts billions of people,
or will wipe out the Brazilian rain forest,
or will collapse the ice sheet,
or will do one of these other abrupt climate changes
that we see the record of.
And the possibilities are mostly out on the bad side.
Now, I have had the remarkable experience
of testifying to congress in many cases,
and I have to admit that at least in a couple of cases,
I have been involved in this argument:
"This is our best estimate." "Couldn't it be better?"
"This is our best estimate."
"Oh, it could be better than that."
"This is our best estimate." "But what about being better?"
Look, we've heard both sides.
Now, to be honest, if you wanted to hear both sides,
it would be a different discussion.
The science is in the middle,
and the middle is actually on the optimistic side,
and that's really what we learn by studying history
for a very long time.
Now, I helped make this TV miniseries,
it's based on a book I wrote,
we ran a MOOC – there are resources,
some that you don't have to pay for, very, very clear.
The TV is all on for free; the MOOC,
you can still go get it for free.
Be very clear: this does not tell you
who you have to vote for,
it does not tell you what you have to do.
But I can tell you, from the full story,
that we're the first generation in history
that can build a sustainable energy system
that powers everyone forever, without changing the world.
If you pretend I'm a liar, you pretend the Air Force
doesn't understand radiative transfer,
you end up, eventually, with a smaller economy,
with fewer jobs, less national security,
less insurance against disasters,
and a dirtier environment _____ _____ _____.
If you include the science and use it
with what you wanna do and where you wanna go,
you can actually end up much better off across the board,
whether it's environment economy,
employment equality, it's all there.
We can do this, there's no reason for panic whatsoever,
but be very clear that the whole story
is that we can use science and engineering,
and all the other things that you teach,
the people who market, the people who invest,
the people who teach, the people who advise,
we can use what we do to make a better world.
And we really can.
And I thank you for coming out and sharing this time with me,
and I hope we'll have a chance to chat, now.
Male: One of the first questions that we have,
coming from Melinda,
asks if any of the data from the ice cores
that are cut get lost in the cutting process.
She says, "I imagine that even a tiny sliver of ice missing
from one that's very, very far down
can represent a good period of time."
_____ it – we actually had one piece of core
that fell out of the barrel, in Greenland.
We saved all the ice,
but it got a little bit messed up, that does happen.
The modern drilling, though, what's –
the improvement in quality has been so fantastic
that you really can sort of put a – you go down
and bring up a chunk of core, and then go down and get more,
and you can just put'em back together and it's beautiful.
And the bubbles have high pressure and they try to break,
but they've built these special nettings
to hold it together, now.
And the quality of the drilling has become so good
that the old losses have essentially disappeared.
Female: And let me jump in, too,
and say that last season at the waste divide,
we developed and were successfully involved
with getting replicate cores.
So there's now the capability, on the technology side,
to go back into some of the previous boreholes
and, with this new technology, drill basically parallel cores.
So, at areas of high interest, like when the climate changes
from a really cold period to the Holocene,
they can go back, now, and get more data,
which is really helpful in duplicating some of that data
that we need.
The world had never seen this before: you drill down,
and then you sort of go out the side of the hole
and go next to it.
And no one had ever done that, and they did it, and they won
[inaudible phrase]. [Laughter]
Male: That's great.
Yeah, we have a question from Terry, here,
which says that, Richard, you use a lot of analogies
in your teaching others about climate change.
And Terry's wondering, which do you feel
are some of the most effective
for overcoming difficult concepts with younger students,
such as those in middle school?
Yeah, I think you – I mean, there was a note, here,
about Muskrat Love.
You know, probably not what's involved in Muskrat Love.
But [audio cuts out]
I think it's the ones that work for you.
If you believe in it, if you can take it
from there to the material, the students will come with you.
I really think that it's – they're smart,
they have a remarkable range
of at least sort of they've touched on things.
They know the Beatles if they don't know Muskrat Love,
but, you know [laughs]
– so, I think it's the ones that work for you.
And find ones that you're comfortable with,
try'em on your neighbors, your friends,
and those are probably the ones to use.
Male: Thank you. I have a question from Angela,
she mentions that the wild swings in climate in Greenland
are what people who like to pretend that climate change
is not happening use to say,
"Oh, see, there have always been huge changes in climate."
I mean, how do you speak to that?
You know, I think it's pretty straightforward:
there have always been forest fires,
but we have arson investigators
because sometimes people burn things.
And you really want your arson investigator
to know natural forest fires, so they know the difference.
The person who understands natural forest fires
is probably best positioned to realize
how destructive a human-caused one can be.
And somebody who had never seen a fire
and didn't know what it could do wouldn't be worried about arson.
And so, in the same way, by learning what nature has done,
we can more clearly see the human fingerprint
on what is happening now.
And we more clearly appreciate how important this is.
Male: Thank you. And _____
would like to know, what sort of event do you
feel might've caused the abrupt warming
such as you presented in your slide about the driest period?
And how would all that melting ice impact
the oceanic circulation?
Right, so, too much melting ice, clearly,
allows it to freeze in the north.
Our best understanding now is that a lot of this
is just sort of a natural oscillation,
and when there is a big ice sheet around the north Atlantic,
that the melting freshens it and then it freezes.
But then the Atlantic is getting saltier and saltier,
because the wind is blowing across Panama with evaporation.
And as it gets saltier and saltier,
at some point, it will start to sink,
and then the sea ice goes away. And so, we think this is one,
it's – you know, if you push just a tiny bit –
if I was trying to knock over something balanced
on the shelf behind me,
you push just a little bit and nothing happens.
You push a little more, and it falls over.
And we think this is one that a very gradual change
in the saltiness of the Atlantic
[glitch interferes with audio]
and it's just fascinating that that focuses in there.
Male: Some other questions that we have from folks –
actually, one of them which has come up a little bit,
folks are, you know, asking a lot of questions about methane.
And we hear a lot about methane as being particularly important
with areas of permafrost melting,
and it's bubbling up from the oceans and whatnot,
and it being a strong climate gas.
So, can you sort of present
maybe a brief discussion of methane in comparison to CO2
and its effect on global warming?
Yeah, so, methane matters,
but CO2 is the bigger part of the story.
When we put methane in the atmosphere, in –
you know, methane is natural gas,
and we take it out of the ground and we burn it,
and we make CO2 by combining it with oxygen.
When nature puts methane in the air, in about ten years,
it combines with oxygen and it makes CO2.
So, there is warming from methane, nature –
whatever we do in warming the world,
we have high confidence that nature will use methane,
as well as CO2, to make our warming bigger.
But mostly, the methane turns to CO2,
and mostly, the leakage is fairly slow.
So, even the dramatic stories you're hearing
about methane belches from the Arctic
are still slow compared to our burning of fossil fuels.
So, methane matters,
but CO2 is ultimately going to be the big story.
And so, I would simply focus on methane
as being an amplifier that we don't like,
but it will almost certainly be small enough
that our decisions to handle CO2 will help handle methane.
Male: What a great segue into our next question
that's being asked by Lori,
which is, do you have any recommendations about ways
that we may be able to get off fossil fuels
as quickly as possible?
Female: [Laughs] You knew that was coming.
I knew that was coming.
But some of it is invention, some of it is –
so, we tried very hard in these TV shows –
which are completely free to you,
they're on YouTube, they're at our website,
they're all out there free to you –
to show the ways that people were getting off fossil fuels.
And to show how much good it was
doing for the people who were doing this.
And there's a whole lot of things
that you can work through.
And it really is sort of amazing what is possible, now.
So, some of it is being interested,
some of it is wanting to do so.
If you go to the – beyond the individual level
to the collective level,
I've had the remarkably wonderful experience of working
with some really good economists on this.
And what they say, very clearly,
is that right now, we subsidize fossil fuels.
There actually was a report came out
from the International Energy Agency,
and another one came out from the International Monetary
Fund, said subsidies for fossil fuels
are much bigger than subsidies for renewables.
And if you include the whole package,
that the US was actually
the biggest subsidizer of fossil fuels.
If you look at narrowly-defined ones, we're not,
but if you look at sort of all the tax rates and everything.
And then in particular, if you made wind turbines
and you had scraps left,
you'd have to pay somebody to throw them away.
And if you have trash in your house,
you pay somebody to throw it away.
And if you do something in your toilet,
you pay somebody to throw it away.
But the CO2 changes the climate for free.
And what the economists say, over and over and over,
put a price on changing the climate,
use that money to reduce the tax on something else you want,
or to do something you want.
And the economists love the idea of taxing carbon
and not taxing your paycheck.
And they say if climate change were a lie, taxing carbon
instead of your paycheck would make us better off anyway,
in all likelihood, or at least no impact on the economy.
And if you include the benefits of avoiding climate change
and the other things
you avoid with switching towards renewables,
it makes us a lot better off.
So, the big picture is to promote –
that the economists say. Now, like I say, I try very hard
not to tell you what to vote for,
but a lot of economists have said
you put a price on carbon, and that that is a way
that it can be internationalized, as well.
So, if a fair part of the world, if the US and Europe
and maybe someone else agreed to tax our own carbon,
then you can say, to other countries,
"Here's the deal: you tax your carbon,
you keep the money, do whatever you want with it.
Or: we will tax everything that we trade with you,
and we will keep the money. What would you like?"
[Laughter]
Male: Well, and let's hope that people will be listening
[inaudible phrase] hope.
You know, I actually did have an interesting question,
I thought, going back to some of the discussion about ice cores
and the drilling, and actually,
Kathleen wanted to know how and where the ice cores are stored.
And are they processed with a working section
and in an archive section,
the same way that sediment cores are treated?
Smart _____.
So, we have this wonderful National Ice Core Laboratory,
which is in the Denver Federal Center in Lakeland, Colorado.
It is funded by the National Science Foundation,
it is hosted –
it's been hosted by the United States Geological Survey,
it was founded, in part, with –
well, you know, wonderful people on both sides, Julia _____
at the National Science Foundation.
Joan Fitzpatrick, who you saw in the snow pit,
was instrumental in making it happen.
And there is an archive of all of these cores stored there.
In addition, there's little bits
in most of the main ice core labs,
so you will find a little bit in Maine
and a little in Colorado and other places,
and having it distributed like this is an extra safety.
But the professionalism and the quality of the storage
in the archival there,
you can get online and find the National Ice Core Lab,
and see what they have, and so on.
It's really a wonderful thing.
Female: One thing I would just share, Richard,
is that it might be interesting for students
to learn that the ice cores
that are drilled have sort of been predetermined
by the science that was proposed.
And so, when the cores get extracted,
people's names are on that, for the most part.
There is an archive that's saved at the NICL,
but in additional, each summer, as those cores come back –
and one of the clips that I showed you
on the Cool Stuff page shows how various graduate students
and people from the different labs
actually come with the cores
that their proposals have proposed to science for.
And chop up the various pieces, and it's determined by,
you know, whether they want the outside piece
for a particular characteristic of the science,
or whether they need the clean pristine interior.
And those segments get, then,
sent out to multiple national laboratories
for all these different types of assay tests.
And it's kind of neat for kids to understand
some of the process of doing research, as well,
and the role that they might have in working with the cores.
Male: That's really fascinating – I had no idea.
You know, one question that we had,
going back to your graph, Dr. Alley,
of some of the rapid changes in climate.
In your graph, you showed some changes
that were very extreme, very fast –
what was the timeframe for those very fast changes _____
_____, were they 5 years, 50 years, 500 years?
And if you like, we can pop your presentation back up.
Yeah, oh, no, this is sufficient.
_____ sort of 10 degrees Celsius or 18 degrees
Fahrenheit in Greenland in something like 10 years,
and some of the parameters changed faster than that.
So, the accumulation –
the snowfall basically doubled within about three years,
so, in Greenland, they were very, very fast.
They appeared differently in different places.
We see them beautifully in Antarctica,
but they're slower there,
because they sort of have to mix through the ocean to get there.
And they're not the whole world up
and the whole world down; they're rearrangements,
because they did not have a huge effect on CO2,
so they didn't have a huge effect on the greenhouse.
So, when you change CO2, the world tends to –
there's wiggles, but the world tends to go together.
When you change ocean currents,
you get more interesting patterns.
Male: Thank you. And, you know, in closing –
'cause we're running just a few minutes over,
which is fine [laughter] – just a final question,
and then I just have one or two final comments to close out on.
Will individual investments in renewable energy,
energy efficiency, electric vehicles,
be enough to reduce CO2 emissions?
I mean, Elizabeth mentions that she doesn't see, really,
politicians stepping up to solve these problems.
It's an interesting thing, and I'll try to keep this short,
but when I first testified to a subcommittee at the US senate,
it was chaired by a republican
who was about to introduce legislation
to put a cost on changing the climate.
And who was a little – seemed a little unhappy with me
because I was not more of an alarmist about the dangers.
And that was 12 years ago – I think it was 12, right?
So, what is politically –
you know, who's stepping up to the table,
it sometimes has changed, and it can change.
And if people make it possible for our elected officials, I –
I've had the remarkable experience
of talking toe senators without a TV camera,
we got on a plane and went to Greenland
with ten percent of the senate.
And when the doors closed and the camera is turned off,
they were the most amazingly bright, interested,
and interesting people who were looking solutions.
And I think that they are hoping for some help
from their constituents,
and I think that then they actually are interested
in doing good things.
And it's very, very different what you see
when the camera is not running
and when it is, so that is a good thing.
My suspicion is that if you make an investment that you enjoy,
you make an investment that works for you,
other people see that.
And it also helps in the – making this work.
If the person who comes to put shingles on your house says,
"Do you want me to plug in the solar cells while I'm here?"
it's a different world. There were just studies,
recently, that said we buy solar cells,
Germany buys solar cells, we pay about the same amount,
but we pay twice as much to get them plugged in.
And if the startup companies actually learn
how to do this better because they're supported,
maybe it gets cheaper and more people do it.
So, what you do by yourself can't change the world,
but what we do can,
and what we do is a lot of _____.
Male: Amen.
Thank you, Dr. Alley, and thank you, Linda
– really appreciate your time here, this evening,
taking time out of your busy schedules to join us,
Richard, during your conference,
and Linda, while you're taking some family time.
So, really just appreciate taking the time out,
and the energy and the effort to communicate with our educators,
this evening. There are some other –
Thank you to the teachers for coming out –
that's what I'm really impressed [crosstalk].
Female: Yes, awesome. They're the future.
[Laughs]
Thank you all. You have grades to fill out and papers to grade,
and you're here chatting with us about this. Thank you.
Male: All right, well, I will let you guys return, now.
I have some closing comments, and then we will wrap things up.
So, have a good evening.
Female: Right, good night to you all, mm-hmm.
Thank you. Bye.
Male: So, just to let people know that there are
a series of educational resources that we have provided.
You'll see the first few are from Linda Morris,
from the US Ice Drilling Program,
as well as information about the master's class
that she has mentioned,
and the date and time of those webinars.
In addition, there is a link that's down here,
which you can see, from climate.gov.
There are a myriad of educational resources
associated with ice cores and climate change,
all of which have been reviewed by the clean process.
I urge you to take some time and to check those out.
In addition, you should all know that these slides as well
as all of Dr. Alley's
and Linda Morris' presentations are already on the wiki,
as we've mentioned.
Finally, we hope that all NOAA climate students
will complete a reflection of this webinar,
and we're looking forward to all climate students
doing about an hour of independent PD each month,
and reflecting upon it, as you all know.
And with that, please go in, after you leave here,
and check your e-mail inboxes;
you will find our webinar poll already waiting for you.
It's been a pleasure to have Dr. Alley and Linda,
this evening, and your questions will be sent to them and posted.
So, with that, thank you very much,
and have a good night.
[End of Audio]