These are
the continuing notes from the Radio Ecoshock
Show for January 8th, 2010 with Richard B. Alley,
Professor of Geosciences, at Penn State University. Alley is a Fellow of the American Geophysical Union, and a member
of the National Academy of Sciences.
His popular book about ice cores is called "The Two Mile Time
Machine."
Alley was
expected to give one of the best speeches of the 2009 annual meeting of the AGU
- and he did not disappoint. I'm Alex
Smith of Radio Ecoshock, and I'm going to give you a short digest of that hour-long
Bjerknes Lecture to the AGU in San Francisco in December.
Below,
you will find some transcripts from the speech, possibly the only written
transcript available, so far.
The first
20 minutes of Alley's speech go into the many ways that scientists can measure
past CO2 levels. These include actual
air samples trapped in ice cores, plus a whole range of cross-checking
available from sea-bed analysis, shells of creatures, and a list of techniques
to long to list here.
In a
sense, this is the most important foundation for everything we will hear next -
because it establishes how we know. These
are not mere guesses, or religious beliefs, but the results of millions of
careful measurements by hundreds of thousands of scientists around the
world. The result is compiled and
cross-checked by large scientific bodies, ranging from national Academies of
Science, to the Intergovernmental Panel on Climate Change, through peer review
and criticism by the world's scientific community. The results are not opinion, and are moving toward established
facts about our world.
Dr. Alley explains, with graphs, the "Rock-Weathering Thermostat" that operates, over long periods of time, to balance both the CO2 and the temperature on planet Earth. This was developed by Walker, Hays and Kasting in 1981, and has stood the test of further research.
Beyond
the facts, such as the amount of a certain carbon isotope in rocks, we have the
level of theory. Scientific theory
stands until it is proven incorrect, or superceded by a better theory. Einstein's theory of relativity is still a
theory, as is Newton's theory of gravity.
But we managed to send humans into space, and broadcast television,
based on these theories.
In some
areas, we still don't know. That is the
realm of conjecture. We guess, based on
the available evidence, but admit our ideas may be wrong. When dealing with the very deep past of our
planet, there is more conjecture.
As mere
humans trying to understand our home planet, and serious risks we pose to it,
you and I need to go beyond the child's demand for complete certainty. We must embrace an intelligence based on
being able to separate facts, theory, and conjecture. There is a role and a place for each. Just because we are uncertain about some things, does not make
all climate theory wrong! At times,
denialists attempt to defeat science because of it's honesty.
Dr. Alley
tells us about the coldest times, labeled "Snowball Earth". But we begin our radio coverage with an
event that must concern us all: 250 million years ago there was a massive
extinction event called "The Great Dying".
"Basically,
250 million years ago, almost every critter on the planet dies. "The Great Dying", the end Permian
extinction. Maybe 95 percent of the
species go, but because you can keep a species alive with a reasonably small
number of individuals, this is really nasty.
It turns
out that there are bugs in the ocean, green sulfur bacteria, that use hydrogen
sulfide, rather than water in their photosynthesis, and they have very
interesting biomarkers, and those biomarkers are found widespread at the time
of the dying. Which means - and these
things are living in the photic zone of the ocean, and they're living on
hydrogen sulfide, which means that the ocean's surface is filled with hydrogen
sulfide. And if you breath very much
hydrogen sulfide, you die.
And it's
probable that was true for a whole lot of oxygen-breathing critters back in the
past. And so some time here, the ocean
runs out of oxygen, and then it gets [unknown term] and fills up with hydrogen
sulfide, and then it kills off most stuff on the planet.
And it
turns out that happens to be a warm time.
There's a big warming coming up to that and the warming seems to have
been because there was a big volcanism [volcanoes erupting]."
This is
the theory popularized in the book "Under A Green Sky" by Peter
Ward. Listen to our Radio Ecoshock
interviews with Dr. Peter Ward, especially our "Under A
Green Sky" interview in the September 12h, 2008 program, and then his
later explanation "The Medea Hypothesis" in the October 10th,
2009 Radio Ecoshock Show. It's best
to listen to the earlier interview first.
Isn't it important to know how the worst case climate scenario
developed? If that explains how rampant
warming could kill off 95 percent of life on Earth?
One great
extinction, that of the dinosaurs, was not caused by warming or excess
CO2. Of the 5 great extinctions,
scientists theorize 4 were caused by warming, but the dinosaurs were killed off
by climatic conditions set off by the crash landing of a meteorite into the
current Gulf of Mexico. The dust blown
into the upper atmosphere brought a darkening and cooling that ended many life
forms.
We know
that Earth has experienced extreme warming, where crocodiles played in tropical
seas at the Poles.
"Now
come a little farther forward in time, and we're now in the Saurian Sauna of
the mid-Cretaceous. It's still
hot. There's no ice near sea level at
the Poles, anywhere. You have balmy
temperatures, you have forests crowding up to the edge of the Arctic Ocean.
The
continents are not that different from now.
And if you put them in a model, as has been done, you melt all the ice,
and the sea level gets a little higher, and that changes the planet's Albedo a
little, and you get a little bit of warming.
And you move the currents around, and you get a little bit of warming
with some configurations, you can't get much.
And so
it's really stinking hot, and the only explanation we can find on this is that
CO2 is really high again. Probably again
because volcanism is running pretty fast.
If you put high CO2 in the models, you sort of match what happened,
except the world seems little bit too warm at the Poles. If you leave the CO2 out of the models, you
don't get very close.
The only
way we can attribute this warmth, of having an ice-free world, is to have a
high CO2."
But let's
look at another horror example from Earth's past climate shifts. This is the Paleocene-Eocene Thermal
Maximum - something that looks possible for us even today.
"And that's a very interesting little blip. It's where the Paleocene meets the Eocene, and it is a thermal maximum, so we call it the Paleocene-Eocene Thermal Maximum...
What do
we find there? There's a big isotopic
anomaly that says 'CO2, CO2, CO2'.
Maybe starting as methane, but going to CO2.
There's a
big temperature change. The whole world
is already hot, and it cranks up a few degrees C. in a fairly short order. The ocean acidifies, and all the shells on the
sea floor are dissolving, and there's a big extinction event of things that
live on the sea floor.
Pretty
much all the ecosystems get kicked around.
There's huge migrations, there's seems to be the start of some evolution
going on. There's a lot of ecosystem
disruption. Things get out of place,
and out of time, as it were.
You can't
possibly blame this on drifting continents.
The CO2 rises in a few thousand years, and it falls in tens of
thousands, a hundred thousand years, so this is not a drifting continent
thing. The CO2 shows up and it gets
hot. And it's fast compared to other
things.
And the
way that it recovers looks just like our carbon cycle models."
Alley
continues with a detailed time-line of Earth's temperatures, showing a direct
correlation between CO2 and temperature periods. The measurements again are amazing for their breadth, running
from soil and sea samples, to fossil teeth, to leaf damage in fossil
leaves. The work of scientists all over
the world, over decades. Boom! the CO2
goes up, and Boom! so does the temperature.
Like dancing partners.
There
were times that didn't seem to fit, beyond the meteorite hit. But, says Alley, in the last decades, almost
all of those have been reasonably explained, and most turn out to be
CO2-related after all.
At minute
40 in the talk, Richard Alley goes into the science discounting other theories
of climate disruption, such as the volcanoes and the Sun. Of course, there are many factors in this
complex system, and volcanoes and the Sun, among others, do matter. But myriads of scientific studies show
they are not "the control knob" when it comes to climate. CO2 is.
One
theory, which still needs more research is:
"People
say "Oh, wait a minute, the Sun doesn't change much, but the Sun modulates
the Cosmic Rays, the Cosmic Rays modulate the clouds, the clouds
modulate the temperature so the Sun is amplified hugely."
I believe
this is the main theory from dissenting University of Alabama scientist Roy
W. Spencer. He's coming out with
two new books from the Conservative publisher Encounter Books, titled
"Climate Confusion: How Global Warming Hysteria Leads to Bad Science,
Pandering Politicians and Misguided Policies That Hurt the Poor" in
January 2010, and "The Great Global Warming Blunder: How Mother Nature
Fooled the World's Top Climate Scientists" in March 2010. A barrage of denial of human-induced climate
change, and a comfort to fossil fuel producers and users everywhere.
Alley
says of this theory:
"It's a really interesting hypothesis. There's really good science to be done on this. But we have reason to think it's a fine tuning knob. Because this record, this is sixty thousand years ago on the left, up to today, and this is a record that is Beryllium 10 in the ice core. And Beryllium 10 is made by cosmic rays.
Now the
Sun modulates cosmic rays, so do the magnetic field. Forty thousand years ago, the magnetic field basically zeroed
out, in what we call the Le Champs anomaly, for a millennium or so. And when it did, the cosmic rays came
screaming into the Earth's system, and you see, and basically in all
sedimentary records, this peak in cosmic rays-produced nucleotides.
We had a
big cosmic ray signal - and the climate ignores it. And it's just about that simple.
These cosmic rays didn't do enough that you can see it. So it's a fine tuning knob at best."
Alabama
scientist Roy W. Spencer has also denied the theory of evolution, replacing it
with intelligent design and creationism, theories embraced by the deeply
Conservative Christian movement.
Here
is the end of the talk by Professor Richard B. Alley, to the American Geophysical Union,
December 2009, in San Francisco:
"So
where do we end up? ... If higher CO2
warms the Earth, climate history makes sense.
And if CO2 doesn't warm, then we have to explain why the physicists are
stupid, and we also have no way to explain what happened.
And it's
really that simple. We don't have any
plausible alternative at this point, and so it surely looks like it...
CO2 can
be a forcing. It can be a feed-back. The warming effect of a CO2 molecule - it
does not remember why it's there. It
only remembers that it is there. And
the paleo-climate data shows that sort of the mid-range models are right, and
if there's a problem, the world is a little more sensitive to CO2 on some time
scales than the models tend to predict.
Now, be
clear. There's lots of knobs that
control the climate. The Sun knob,
we're really lucky it doesn't get twiddled very much. The cosmic rays, the space dust, the magnetic field, and the
other knobs, if they matter, we can't find it yet.
There are
really interesting things to be learned.
And I hope that the science rolls forward on those. But so far, they're either not doing
anything, or they're not doing much.
They are fine tuning knobs, and that's how it looks.
This is
not a regional story! You close the
Isthmus of Panama and the people who used to have coastal property don't
anymore. Their climate changed.
You take
India from the Pole, and you run it to the Equator, and it's climate
changes. The Younger Dryas was a big
regional thing. There's lots of things
in regional climate, that don't do much to the globe. The Younger Dryas is warm in the South and cold in the North, so
it doesn't do much to the global temperature.
So, in
terms of things that people care about, CO2 is just the start, it's not the
end. There's real interesting things to
be done in here. And I think there's a
lot more work that needs to be done here yet, because where we really stand
now, we're not quite yet at that pound on the table, this is nailed, we're done
and this is our confidence interval level.
The
paleo-climate date they are coming in real fast, they're really good, it's
really sharp. But, sort of, these
latest advances have not had time to percolate through to the IPCC yet. And so we're going to see more on this. We're going to see more discussion on
this. This story is very clearly not
done.
But it's
fairly clear where we stand now. Which
would be: an increasing body of science indicates CO2 has been the most
important controller on the global average climate of the Earth."
[Applause]
But
what if we burn all the fossil fuels we can get our hands on?
Richard Alley answers this question in the short Q and A session.
"The question was: if we burn we burn all the fossil fuels, where do we get to. And there's this huge gap between sort of proven reserves, and what we think is out there if we're really clever and really desperate.
And so,
do we get it out of the oil shales, do we get it... and people are kicking
around numbers like five or six thousand gigatons, I think is the number. There's a big number that's floating around
on what might be recoverable.
And if
you take all of that, and you turn it to CO2 pretty fast, there's some chance
of getting above that Cretaceous level.
Like I say, the temperatures might have been a little high at that site,
because the Atlantic is a little narrower, and so the ocean circulation has slowed
a little bit - but that was 37, 38 sea surface temperature. That was hot.
So you
start thinking about this, and say 'well you know' if we really crank it up,
are we really confident we're stopping at 2 or 3 or 4 or 5 or 6 or 7, or, you
know - you can think of a burn it all future getting really hot."
In other
words, out of control global heating, where the seas could reach 38 degrees
Celsius, or 100 degrees Fahrenheit - hotter than the human body.
According
to NOAA the 20th century average sea surface temperature was 16.4 degrees C, or
61.5 degrees F. If we burned up all the
fossil fuels, it is conceivable the average sea temperature could more than
double in Celsius, or rise about 40 degrees Fahrenheit. Given what it takes to heat water, that kind
of super-record warming would presumably take at least centuries, if not
millennia, but in our strange case of rapid emissions, we really don't
know. Human fossil mining is an
ahistorical event, nothing in the natural record prepares us for this.
Surely
humans, and the ecosystems which support humans, would have gone extinct before
that happens? Maybe not. The delay in warming, caused by sea
absorption, among other factors, means we could burn many gigatons of carbon,
before we see the results a generation or two later. But then, the change can last at least 100,000 years, as shown by
David Archer in his book "The Long Thaw" (see our Radio Ecoshock
interview with Dr. Archer here: http://www.ecoshock.net/gn960/gn960_090920_Archer_LoFi.mp3)
We are already
doubling tar sands production, and frackin gas shales, while drilling miles
deep below the ocean - all to get more fossil fuels. Right now, barring a vast revolution in our economy, we are
headed toward Thermageddon, as described by the late Greenpeace founder, Robert
Hunter.
[http://www.ecoshock.org/podcasts/HunterThermageddon.mp3]
[A7
optional Can We Remove CO2? Rock weathering etc...]
But wait,
we didn't allow Dr. Alley to answer one of the biggest denier complaints: that
the climate record often shows CO2 following a temperature rise - so how could
CO2 cause climate change? That's why
they want him fired, if not charged with crimes against humanity.
Let's
quickly dive into that.
[CO2 lag
explained 4 min 42 sec no transcript, sorry, available only in audio]
My
understanding of Dr. Alley's explanation is the same as he said at the end of
his speech:
"CO2
can be a forcing. It can be a
feed-back. The warming effect of a
CO2 molecule - it does not remember why it's there. It only remembers that it is there."
When
other lesser control knobs, like exploding chains of volcanoes, or even the
regular tilt in Earth's orbit, begin the process of warming - CO2 becomes an
amplifying factor which drives the planet into a much warmer state. That has happened many times.
But now,
for the first time, a species on Earth has brought out CO2 accumulated over
huge eras, and burned it in a century or two.
In this case "CO2 can be a forcing". That is, human can trigger a great warming event, and it seems
almost certain we have done so.
Could
we save ourselves by mimicking natural processes?
That's the last question of the night.
So far, that doesn't look possible, because things like rock weathering
take thousands, tens of thousands of years.
If we try to mine the right rock, grind it up, expose it to form calcium
carbonate - the energy involved in the process might be greater (and more
carboniferous) than the carbon removed.
It is easier, Dr. Richard Alley says to applause, to prevent the carbon
from entering the atmosphere in the first place.
In
February 2009, Richard Alley shared the 2009 Tyler Prize for Environmental
Achievement with Veerabhadran (Ram) Ramanathan, "for their scientific
contributions that advanced understanding of how human activities influence
global climate, and alter oceanic, glacial and atmospheric phenomena in ways
that adversely affect planet Earth."
I'm Alex Smith. Feel free to download and share this program with others - from our web site, ecoshock.org.