Transcript: David Archer | Mar 17, 2007

[Theme music plays]

The opening sequence rolls. The logo of “Big Ideas” featuring a lit lamp bulb appears against an animated yellow slate.
Then, Andrew Moodie appears in the studio. The walls are decorated with screens featuring lit lamp bulbs, and two signs read “Big Ideas.”
Andrew is in his early forties, clean-shaven, with short curly black hair. He's wearing a beige shirt under a brown coat.

He says HELLO!
I'M ANDREW MOODIE AND THIS IS
BIG IDEAS,

He shows a folded newspaper and says
AND THIS IS A NEWSPAPER!
AND IT'S FULL OF STORIES ABOUT
POLITICIANS GOING AFTER EACH
OTHER BECAUSE THE OTHER
POLITICIAN DOESN'T HAVE THE
PROPER UNDERSTANDING OF CLIMATE
CHANGE.
AND IT DOESN'T MATTER WHAT
POLITICAL STRIPE YOU ARE, IT'S
THE POLITICS OF FINGER-POINTING.
MAN, THAT'S WHERE IT'S AT.
AND DOING SOMETHING, WELL, DOING
SOMETHING TAKES UNDERSTANDING,
FORETHOUGHT, AND MONEY.
TO POINT A FINGER HAS A VERY,
VERY LITTLE CONSEQUENCE EXCEPT
PERHAPS A CHANCE TO GET YOUR
FACE AND NAME IN THE NEWSPAPER.
NOW BEFORE YOU OUT THERE WAG A
CRITICAL FINGER AT ME, I'LL HAVE
YOU KNOW THAT MY WIFE AND I USE
ANGEL CLOTHS INSTEAD OF A LOT OF
NASTY CHEMICALS.
I BIKE EVERYWHERE, AND THIS
NEWSPAPER IS GOING RIGHT INTO
THE RECYCLING BIN THE MOMENT I'M
DONE WITH IT.
NOW, OF COURSE SOME OF YOU MIGHT
SAY THAT THE VERY FACT THAT THE
TREE WAS CHOPPED DOWN TO MAKE
THIS NEWSPAPER IS ITSELF A
SERIOUS ECOLOGICAL
FAUX PAS.
EVERY TREE IS ESSENTIAL TO FIGHT
CO2 AND RECYCLING ONLY CREATES
MORE GREENHOUSE GASES THROUGH
THE COAL THAT'S BURNT TO POWER
THE RECYCLING PLANT.
AND I WOULD SAY TO YOU THAT--
WELL, I WOULD SAY THAT YOU AND I
ARE GOING TO LISTEN TO DAVID
ARCHER.
HE IS A COMPUTATIONAL OCEAN
CHEMIST AT THE UNIVERSITY OF
CHICAGO AND HE IS GOING TO SPEAK
TO US ABOUT GLOBAL WARMING AND
THE EFFECTS OF GREENHOUSE GASES.
IT'S TIME TO PAY CLOSE ATTENTION.

A clip plays in which David Archer stands on a stage in a university classroom. He room is dimly lit and a giant screen shines behind him.
David is in his early forties, with short curly brown hair and a stubble. He’s wearing a beige suit, white shirt, and pin dotted black tie.

David says THE GLOBAL
WARMING FORECAST IS NOTHING NEW.
THIS IS THE FIRST PAGE OF A
PAPER PUBLISHED IN 1896 BY A
SWEDISH CHEMIST NAMED SVANTE
ARRHENIUS, AN ASTONISHING PAPER.

A picture of the paper appears on the screen. It reads “Philosophical magazine and journal of science. Arrhenius, 1896.”

David continues HE PREDICTED THAT DOUBLING THE
CO2 CONCENTRATION OF THE
ATMOSPHERE WOULD RAISE THE
TEMPERATURE OF THE EARTH BY
ABOUT 4 TO 6 DEGREES CENTIGRADE.
AND NOW, AFTER A CENTURY OF HARD
WORK AND EXPLOITING COMPUTER
POWER AND EVERYTHING, WE NOW
THINK IT'S 3 TO 5 DEGREES
CENTIGRADE.

[Audience laughter]

David continues SO THAT'S WHAT
WE'VE BEEN--
THAT'S WHAT WE'VE BEEN DOING
WITH, UH--
BUT WHAT'S CHANGED IS THAT THE
TEMPERATURE IS ACTUALLY STARTING
TO WARM IN RESPONSE TO RISING
CO2 CONCENTRATIONS.
SO, AS RECENTLY AS 1990, THE
INTERGOVERNMENTAL PANEL ON
CLIMATE CHANGE SAID, WELL,
THERE'S NOT ENOUGH WARMING YET
TO DISCERN IT ABOVE THE NATURAL
NOISE OF NATURAL VARIABILITY,
BUT WE PREDICT THAT, BY THE END
OF THE CENTURY, WE WILL BE ABLE
TO PICK OUT GLOBAL WARMING FOR
SURE.
AND ACTUALLY, IT CAME EARLIER
THAN THAT.
IN 1995, THE IPCC SAID THAT
THERE IS A DISCERNIBLE HUMAN
IMPACT ON CLIMATE.

A new picture on the screen shows two photographs of a glacier captioned “1978” and “2004.” Another caption reads “Ice sheets and glaciers are melting around the world.”

David continues SO ICE SHEETS AND GLACIERS ARE
MELTING ALL AROUND THE WORLD.
IT'S VERY DIFFICULT FOR A YOUNG
GLACIOLOGIST TO FIND AN
ADVANCING GLACIER TO STUDY
ANYMORE BECAUSE THEY'RE ALL
RECEDING.
I THINK THERE'S ONE IN NORWAY.
THE WARMING THAT HAS BEEN
OBSERVED IS REPRODUCED IN ALL OF
THESE PLOTS AS THE THICK, GREY
LINE THERE.

The presentation changes to a graph and David points at it as he continues
IT'S SORT OF--
THERE IS A PERIOD OF WARMING
FROM RIGHT AT THE TURN OF THE
CENTURY TO ABOUT 1940 AND THEN A
PERIOD OF SLIGHT COOLING FROM
1940 TO 1970, AND THEN WARMING
SINCE THEN.

A caption appears on screen. It reads "David Archer. Department of Geophysical Sciences. University of Chicago. ‘Global warming: Understanding the forecast.’ Perimeter Institute, Waterloo. December 6, 2006."

David continues AND IF WE TRY
TO EXPLAIN THAT USING ONLY
RISING CO2 CONCENTRATIONS, WE
MISS THIS INITIAL HUMP AND
THINGS LOOK TERRIBLE.
AND SO, YOU CAN STILL HEAR
PEOPLE SAY, WELL, OBVIOUSLY
GLOBAL WARMING IS A MYTH BECAUSE
LOOK HOW TERRIBLE IT LOOKS.
BUT WHEN WE PUT
TOGETHER BOTH THE ANTHROPOGENIC,
WHICH MEANS HUMAN-CAUSED--
AND IT'S A FUNNY WORD.
ANTHROPOGENIC SOUNDS LIKE YOU'RE
MAKING PEOPLE RATHER THAN, UH--
COMING FROM PEOPLE.
BUT THAT'S THE WORD THAT WE'RE
STUCK WITH.
YOU PUT TOGETHER THE
ANTHROPOGENIC AND THE NATURAL
forces, THEN YOU CAN EXPLAIN
THE TEMPERATURE TRENDS IN THE
LAST DECADES QUITE WELL.
SO, YOU KNOW, BY THE NORMAL
RULES OF SCIENCE, HERE'S AN
EXPLANATION.
IT'S THE SIMPLEST EXPLANATION
AND IT WORKS AND SO, YOU KNOW,
THERE YOU GO.

A new chart appears with the caption “Only greenhouse gas forcing looks like the recent temperature rise.”

David continues THIS IS WHAT THE VARIOUS
forces OF CLIMATE CHANGE LOOK
LIKE.
SO THESE ARE ALL IN UNITS OF
LOTS PER METRE SQUARED.
SO A LOT IS A UNIT OF ENERGY,
LIKE A HAIR DRYER OR A, YOU
KNOW, CAR STEREO OR SOMETHING.
AND ALL OF THESE PLOTS HAVE THE
SAME--
ONE WATT PER METRE SQUARE IS THE
SAME DISTANCE ON THE PLOTS.
SO, AT THE TOP, YOU CAN SEE THAT
THE SUN WARMS UP AND COOLS DOWN
A LITTLE BIT OVER THE DECADES.
NOT A WHOLE LOT.
HERE IS THE WARMING IMPACT OF
GREENHOUSE GASES, PRIMARILY CO2.
THERE ARE OTHER GREENHOUSE GASES
LIKE METHANE BUT CO2 IS THE BIG
ONE.
AEROSOLS, THESE ARE--
THE SORT OF HAZE THAT COMES OUT
OF COAL POWER PLANT SMOKESTACKS
AND IT REFLECTS LIGHT BACK OUT
TO SPACE.
AND SO THIS IS, UH--
THIS LEADS TO COOLING.
AND THEN VOLCANOES PUT HAZE UP
INTO THE ATMOSPHERE, TOO.
ENOUGH OF IT, ALL AT ONCE, THAT
YOU GET A REALLY HIGH CLIMATE
FORCING, BUT IT'S A VERY SPIKY
THING.
IT'S A VERY SHORT-LIVED THING.
SO THE LAST BIG VOLCANO WAS
MOUNT PINATUBO THAT COOLED THE
EARTH DOWN FOR A YEAR OR TWO BY
HALF A DEGREE OR SOMETHING LIKE
THAT.
BUT THE POINT IS THAT, IF WE
WANT TO EXPLAIN THAT LAST UPTAKE
OF WARMING SORT OF HERE, THE
ONLY WAY WE CAN DO THAT IS WITH
THE GREENHOUSE GASES 'CAUSE NONE
OF THE OTHER forces LOOK LIKE
THAT.
YOU CAN HEAR PEOPLE TALK ABOUT
THE CLIMATE IMPACTS OF COSMIC
RAYS OR SOLAR VARIABILITY OR
ANYTHING LIKE THAT BUT NONE OF
THOSE CAN EXPLAIN THE WARMING
THAT WE'VE SEEN.
SO NONE OF THOSE ARE A GOOD
COMPETING THEORY TO GLOBAL
WARMING.

New charts pop up. The titles read “Temperature forecast: 2 to 4 degrees centigrade warming by 2100” and “General increase in precipitation in a warmer world.”

David continues SO THIS IS WHAT THE FORECAST
LOOKS LIKE.
IT DOESN'T LOOK SO TERRIFYING,
YOU KNOW, ON THE FACE OF IT.
THE FORECAST IS FOR 2 TO 4,
MAYBE 5 DEGREES C OF WARMING
GLOBALLY AVERAGED BY THE END OF
THE CENTURY, BY THE YEAR 2100.
WARM AIR CAN HOLD MORE WATER
VAPOUR THAN COLD AIR SO, WITH
THE WARMING OF THE GLOBE COMES
THE SLIGHT WARMING IN THE
AVERAGE PRECIPITATION BY A FEW
PERCENT.
SO ONE OF THE PIECES OF THE
GLOBAL WARMING RESPONSE THAT
ARRHENIUS PICKED UP WITH HIS
PENCIL AND PAPER BACK IN 1896
WAS THAT THE WARMING IS MORE
INTENSE IN HIGH LATITUDES.

Two colourful charts pop up. They show the natural temperature changes from 1750, the changes for the year 2100, and the changes for the year 2300. Warming is most intense farther from the Equator.

David continues SO YOU CAN SEE FROM THE COLOURS
HERE, IT'S MORE PRONOUNCED IN
THE BOTTOM FIGURE THAT THE HIGH
LATITUDES ARE WARMING
CONSIDERABLY MORE THAN THE
TROPICS DO AND THIS IS BECAUSE
ICE, WHEN IT EXISTS, IS VERY
REFLECTIVE AND IT SHINES
SUNLIGHT BACK OUT TO SPACE.
IT REFLECTS THE LIGHT.
WHEN YOU MELT THE ICE BY WARMING
A LITTLE BIT FROM THE CO2, YOU
THEN ABSORB THAT SUNLIGHT AND SO
YOU GET EXTRA WARMING.
SO THIS IS CALLED AN ICE ALBEDO
FEEDBACK.
ALBEDO MEANS THE REFLECTIVITY OF
THE ICE TO VISIBLE LIGHT.
AND SO THAT'S WHY YOU GET MORE
WARMING IN PLACES LIKE ALASKA
AND SIBERIA THAN YOU DO OTHER
PLACES.
AND YOU SEE THAT IN THE
TEMPERATURES TODAY, ACTUALLY,
ALREADY.
SO I REALIZE THIS PLOT MAY BE A
LITTLE SMALL FOR YOU TO SEE THE
SPECIFICS BUT THIS IS THE PLOT
OF THE MODEL RESPONSE OF THE--
JUST THE LANDSCAPE OF THE
SURFACE OF THE EARTH.

A new colourful world map appears showing the warming in 2000 and the projection for 2100.

David continues IF YOU JUST KIND OF TAKE OFF
YOUR GLASSES AND LOOK AT THE
MAPS, YOU CAN SEE THAT THE HIGH
NORTHERN LATITUDES IN THE TOP
PLOT, WHICH IS THE PRESENT DAY,
YOU HAVE ALL OF THIS TUNDRA AND
DESERT AND POLAR DESERT SORT OF
HIGH LATITUDE BIOMES AND THOSE
ALL SORT OF VANISH BY THE YEAR
2300, WHICH IS THE END OF THIS
SIMULATION.
WE HAVE THERMOMETERS THAT GO
BACK TO ABOUT 1860 THAT ARE
RELIABLE.
FAHRENHEIT INVENTED THE FIRST
THERMOMETER AND VERY QUICKLY
THEREAFTER THE TEMPERATURE
SCALES BECAME STANDARDIZED, AND
THE FREEZING AND MELTING POINTS
OF WATER, THOSE ARE SORT OF
INVARIANT THINGS THAT YOU CAN
CALIBRATE, TOO.
SO IT'S--
WE HAVE RECORD OF TEMPERATURE
GOING BACK FROM THERMOMETERS
PRETTY FAR BUT THEY DON'T GO
BACK FOREVER.
EARLIER THAN THAT, YOU HAVE TO
PUT TOGETHER WHAT THEY CALL
PROXY RECORDS OF CLIMATES, WHICH
YOU DO BY LOOKING AT THE
THICKNESS OF TREE RINGS.
TREE GROW BETTER IN A WARMER,
YOU KNOW, A WARMER YEAR THAN A
COLD YEAR, FOR EXAMPLE.
OR YOU CAN MEASURE THE
TEMPERATURE DOWN INSIDE THE
EARTH AND TRY TO FIGURE OUT WHAT
THE PROFILE WITH DEPTH TELLS YOU
ABOUT THE CHANGES THAT HAVE
HAPPENED IN THE SURFACE.
THERE ARE ALL KINDS OF CLEVER
WAYS THAT PEOPLE HAVE OF PUTTING
TOGETHER CLIMATE RECORDS.

A new chart shows the average temperatures for the last 2 millennia.

David continues AND SO, BASICALLY, WHAT EMERGES
IS A PERIOD, SORT OF IN THE LATE
PART OF THE LAST MILLENNIUM
CALLED THE LITTLE ICE AGE, WHEN
THE EARTH WAS MAYBE A DEGREE
CENTIGRADE OR SO COLDER.
NOW IT'S NOT COOLER IF THIS WAS
A GLOBAL THING OR IF IT WAS
MOSTLY IN THE NORTHERN
HEMISPHERE.
MOST OF THE TREE RING RECORDS
AND THINGS LIKE THAT ARE FROM
THE NORTHERN HEMISPHERE SO, YOU
KNOW, THERE ARE SOME CAVEATS BUT
ON THE ORDER OF A DEGREE COLDER
OR SO.
BEFORE THAT WAS A TIME CALLED
THE MEDIEVAL WARM CLIMATE OR
MEDIEVAL OPTIMUM CLIMATE, WHICH
MAY HAVE BEEN HALF A DEGREE WARM
OR SO.
SO PUTTING THE PRESENT INTO THE
CONTEXT OF THE PAST, THE
PRESENT-DAY CLIMATE, ABOUT 0.6
DEGREES WARMER THAN THE
LONG-TERM AVERAGE, IT'S KIND OF
COMPARABLE MAYBE TO THE MEDIEVAL
WARM CLIMATE.
THERE ARE THOSE WHO SAY WARMER,
OTHERS WHO SAY NO, NO, NO.
BUT, IN GENERAL, THEY'RE SORT OF
THE SAME ORDER OF MAGNITUDE.
THESE CLIMATE CHANGES IN THE
PAST WERE REAL AND THEY WERE
SIGNIFICANT BUT THEY WEREN'T
SORT OF GLOBALLY CATASTROPHIC,
REALLY.
THE MEDIEVAL WARM HAD ASSOCIATED
WITH IT A TENDENCY TOWARD
PROLONGED MULTI-YEAR DROUGHT.
IT'S WHAT THEY CALL A
MEGA-DROUGHT IN THE AMERICAN
SOUTHWEST THAT SORT SORT OF
WIPED OUT THE MAYAN
CIVILIZATION.
SO THEY PROBABLY WOULDN'T HAVE
GOOD THINGS TO SAY ABOUT THE
MEDIEVAL CLIMATE.
BUT GLOBALLY IT WASN'T A
DISASTER, IT WAS SORT OF A
SUBTLE THING.
AND THAT'S WHAT I WOULD SAY
WE'RE IN NOW.
NOBODY SAYS THAT WE'RE, YOU
KNOW, SUFFERING HERE AND NOW
YET, REALLY, FROM GLOBAL WARMING
ALTHOUGH RESIDENTS OF PACIFIC
ISLANDS, YOU KNOW, MAY DIFFER ON...

A new slide in the presentation reads “Lessons from the past.”

David continues SO, UH, FIRST LESSON FROM THE
PAST IS THE PRESENT-DAY CLIMATE
IS SORT OF COMPARABLE TO THESE
MEDIEVAL WARM OR LITTLE ICE AGE
KINDS OF CLIMATE CHANGES, WHICH
ARE REAL AND NOTICEABLE BUT
THEY'RE NOT GLOBALLY
CATASTROPHIC.
WE CAN LOOK BACK FURTHER INTO TIME.

A new chart titled “Glacial cycles in ice sheets and CO2” shows the CO2 up to 600 thousand years ago, and a proxy for the temperature.

David continues NOW, WE'RE GETTING OUR DATA FROM
ICE SCHOLARS WHO ACTUALLY CAN
DIG OUT LITTLE BUBBLES OF
ANCIENT ATMOSPHERE FROM THE ICE
AND MEASURE THE CO2
CONCENTRATION.
AND THEY SEE THAT GOING UP AND
DOWN.
THIS IS THE PRESENT--
WELL, THE PRESENT-DAY BEFORE
GLOBAL WARMING, THE CO2
CONCENTRATION IS NOW PROBABLY
OFF THE SCREEN AT ABOUT 380.
THEN HERE IS--
THERE ARE SOME RECORDS OF
TEMPERATURE DOWN IN ANTARCTICA.
SO THE GLOBAL MEAN TEMPERATURE
CHANGE BETWEEN THE GLACIAL TIME
AND THE PRESENT DAY WAS ABOUT 5
OR 6 DEGREES C.
SO THAT NOW IS GETTING--
ACTUALLY, THAT'S EVEN LARGER
THAN THE TEMPERATURE CHANGE
THAT'S FORECAST FOR THE COMING
CENTURY BUT, YOU KNOW, THEY'RE
SORT OF COMPARABLE.
THEY'RE SORT OF AN ILK.
THEY'RE BOTH BIGGER THAN A HALF
A DEGREE, LIKE WE'VE SEEN SO
FAR.
AND THE TRANSITION FROM THE
GLACIAL TIME TO THE PRESENT DAY,
THAT IS A HUGE CLIMATE CHANGE.
THERE WERE, YOU KNOW, MILES OF
ICE ABOVE OUR HEADS RIGHT HERE
DURING THE GLACIAL TIME.
YOU COULD TELL THE DIFFERENCE
FROM SPACE THAT, YOU KNOW, THAT
THE CLIMATE WAS DIFFERENT DURING
THE ICE AGE.
THAT WAS A BIG DEAL.
SO THE TEMPERATURE CHANGE IN THE
COMING CENTURY TO THE YEARS 2100
IS SORT OF MORE COMPARABLE MAYBE
TO THE TEMPERATURE CHANGE AT THE
END OF AN ICE AGE AND A MUCH
BIGGER DEAL.
WE SORT OF DON'T WANT TO CONFUSE
WHAT WE'VE SEEN SO FAR WITH WHAT
WE'RE GOING FOR IN THE COMING
CENTURY.
BUT THE TEMPERATURE CHANGE IN
THE FUTURE DIFFERS FROM THE
TEMPERATURE CHANGE COMING FROM
THE ICE AGE BECAUSE, NOW, WE'RE
VENTURING OFF INTO NEW
TERRITORY.
WE'VE BEEN--
THE EARTH HAS HAD ICE SHEETS AND
HAS BEEN ROUGHLY KIND OF THE
SAME PACKAGE OF TEMPERATURES AND
CLIMATES FOR ABOUT 2 MILLION
YEARS.
AND SO, TO GET TO TEMPERATURES
THAT ARE 3 DEGREES WARMER THAN
TODAY, LOOKING INTO THE PAST,
YOU HAVE TO GO BACK, YOU KNOW,
3 MILLION, 5 MILLION YEARS INTO
THE PAST.

A new chart shows that the Earth was 3 degrees warmer 5 million years ago, and even warmer before.

David continues SO, YOU KNOW, THAT KIND OF UPS
THE ANTE A BIT BECAUSE WE DON'T
KNOW SO MUCH ABOUT WHAT THE
WORLD IS LIKE WHEN IT'S THAT
WARM BECAUSE THE LAST TIME IT
HAPPENED WAS A LONG TIME AGO.
AND THEN, ANOTHER SORT OF NOTE
FROM THE PAST WHICH I'LL JUST
MAKE IN PASSING, AND WE'LL KIND
OF SEE AGAIN, A LITTLE BIT, IS
THAT THE FORECASTS--
REMEMBER I SHOWED YOU THE
TEMPERATURES KIND OF RAMPING UP,
YOU KNOW, TO 3 OR 5 DEGREES C BY
THE END OF THE CENTURY AND THE
RAINFALL'S SORT OF SLOWLY
RAMPING UP?
WELL, IN SOME WAYS, THAT WAS THE
BEST-CASE SCENARIO BECAUSE, IN
THE PAST, CLIMATE CHANGES, AS
OFTEN AS NOT, TENDED TO BE MORE
LIKE FLICKERING LIGHT SWITCHES
OR SOMETHING LIKE THAT.
THEY WOULDN'T CHANGE GRADUALLY
THE WAY THE FORECAST DOES FROM
THE CLIMATE MODELS.
BUT RATHER, THE CLIMATE WOULD
TEND TO FLIP-FLOP FROM ONE
STABLE STATE TO ANOTHER JUST IN
A FEW YEARS, YOU KNOW, JUST A
CHANGE.
SO, YOU KNOW, THAT WOULD MAKE A
TRANSITION MORE DIFFICULT IF IT
HAPPENED ALL OF A SUDDEN LIKE
THAT.
THIS IS KIND OF SOMETHING THAT
YOU MAY NOT HAVE HEARD BEFORE,
YOU KNOW, COMPARING GLOBAL
WARMING IN THE COMING CENTURY TO
CLIMATE CHANGES IN THE PAST.

A new slate reads “The future. Fate of fossil fuel CO2.”
It shows that it takes centuries for CO2 to dissolve in the ocean or its uptake and release from terrestrial biosphere; it also takes 5 to 10 thousand years for it to be neutralized by CaCO2 and about 400 thousand years for it to be lithified by weathering of silicate rocks.

David continues YOU KNOW, THAT'S KIND OF GEOLOGY
101 SORT OF STUFF AND I HADN'T
PUT ANY ORIGINAL IDEAS INTO
THAT.
I'M JUST SORT OF SHOWING YOU
THAT.
BUT THE PROGNOSIS FOR THE DEEP
FUTURE, THIS IS SOMETHING THAT
ISN'T WIDELY MENTIONED IN THE
POLICY DISCUSSIONS ABOUT GLOBAL
WARMING.
SO WE RELEASE
CO2 INTO THE ATMOSPHERE AND IT
DOES A NUMBER OF THINGS ON A
NUMBER OF DIFFERENT TIME SCALES.
THE MOST IMPORTANT THING THAT IT
DOES IN TERMS OF HOW MUCH CO2
PARTICIPATES IN IT IS TO
DISSOLVE IN THE OCEAN.
SO, ULTIMATELY,
SOME three quarters OF THE CO2 THAT WE
RELEASE INTO THE ATMOSPHERE WILL
DISSOLVE IN THE OCEANS AND THIS
TAKES A FEW CENTURIES.
ACTUALLY, SCIENTISTS BACK IN
ARRHENIUS'S DAY FIGURED THAT ANY
CO2 WE RELEASED TO THE
ATMOSPHERE TODAY WOULD DISSOLVE
IN THE OCEAN NEXT WEEK BECAUSE,
YOU KNOW, THE OCEAN COVERS three quarters
OF THE SURFACE OF THE EARTH AND
SO WHO'S TO THINK THAT IT
WOULDN'T JUST TOTALLY DOMINATE
THE CO2 CONCENTRATION IN THE
ATMOSPHERE?
ARRHENIUS DIDN'T THINK IT'D BE
POSSIBLE FOR HUMANKIND TO DO THAT.
BUT IT TAKES LONGER THAN THAT
BECAUSE OF THE WAY THE OCEAN
CIRCULATES AND SO WE HAVE TO
WAIT SEVERAL CENTURIES FOR THAT
TO HAPPEN.
THE TERRESTRIAL BIOSPHERE, THE
LAND SURFACE, ALSO TAKES UP
CARBON AND RELEASES CARBON
DEPENDING ON WHETHER, YOU KNOW,
TREES ARE CUT DOWN OR WE'RE
PROTECTING A FOREST FROM FOREST
FIRES OR FERTILIZING IT FROM THE
NITRATE FROM ACID RAINS OR
SOMETHING LIKE THAT.
AND THAT ALSO ADJUSTS ON A TIME
SCALE OF CENTURIES.
AND THEN THERE ARE PROCESSES
WHERE THE CO2 REACTS WITH ROCKS.
SO CO2 IS CHEMICALLY AN ACID.
CALCIUM CARBONATE IS CHEMICALLY
A BASE AND SO THE TWO OF THOSE--
WHILE THE CO2 IN IT DISSOLVES IN
THE OCEAN WILL TEND TO ACIDIFY
IN THE OCEAN SOMEWHAT, SOMETHING
THAT YOU MAY HAVE HEARD ABOUT.
IT'S AN ISSUE THAT'S GETTING--
THERE WAS THAT
NEW YORKER
ARTICLE JUST A WEEK OR TWO AGO
ABOUT THAT.
AND THEN, ULTIMATELY AFTER SOME
THOUSANDS OF YEARS, THE CALCIUM
CARBONATE WILL NEUTRALIZE THAT
BASE.
SO IT'S LIKE YOU HAVE A SOUR
STOMACH AND YOU TAKE A TUMS.
TUMS IS CALCIUM CARBONATE.
AND THEN THERE ARE ALSO CHEMICAL
REACTIONS WITH IGNEOUS ROCKS
THAT WILL ULTIMATELY TAKE DOWN
THE LAST, THE BITTER END OF THE
FOSSIL FUEL CO2, AND THAT TAKES
HUNDREDS OF THOUSANDS OF YEARS.
SO WHAT IT LOOKS LIKE IS THIS.
WE'RE NOW LOOKING AT A TIME SPAN
OF 40,000 YEARS GOING ACROSS THE
WHOLE THING, AND THEN HERE IS--
WELL, I GUESS WE ARE RIGHT ABOUT
THERE.
BUT IF CO2, IF WE BURNED ALL OF
THE COAL, CO2 COULD REACH THIS
HIGH OF A CONCENTRATION, IT
WOULD--
ABOUT three quarters OF IT WOULD DISSOLVE
IN THE OCEAN ON A TIME SCALE OF
CENTURIES AND THEN THE REST OF
IT WOULD BE A SORT OF LONG TALE
THAT TAKES THOUSANDS OF YEARS
INTO THE FUTURE.
SO 25 percent OR SO DOESN'T GO AWAY IN
JUST A FEW CENTURIES.
AND THIS IS THE POINT OF A--
THAT MISSED BECAUSE THIS IS SORT
OF AN AIR ON THE PART OF THE
INTERGOVERNMENTAL PANEL OF
CLIMATE CHANGE, THE IPCC.
THEY GOT IT RIGHT IN THE
DETAILED CHAPTER, YOU KNOW, BACK
ON PAGE 897 OR WHATEVER, BUT IN
THE TECHNICAL SUMMARY THEY PUT
INTO THIS TABLE--

A table pops up.

David continues THIS IS TABLE 1 OF THE SUMMARY--
THAT THE LIFETIME, ATMOSPHERIC
LIFETIME OF CO2 IS 5 TO 200
YEARS.
AND NOW, I MEAN, ONCE IT'S
THERE, IT'S EVERYWHERE.
YOU FIND THAT ON UNITED STATES
ENVIRONMENTAL PROTECTION AGENCY
WEB SITE, YOU FIND IT IN POPULAR
BOOKS ON CLIMATE CHANGE, ALL
KINDS OF THINGS.
THERE WAS ONE BOOK RECENTLY BY
JAMES LOVELOCK, THE GUY WHO CAME
UP WITH THE GAIA HYPOTHESIS,
WHICH IS THAT THE EARTH IS A
LIVING, BREATHING THING.
HE TALKS ABOUT ENGINEERING THE
CLIMATE BACK TO SOME, YOU KNOW--
IF IT GETS TOO HOT, WE CAN
ALWAYS SORT OF ENGINEER IT BACK
DOWN, COOLING IT BY PUTTING SOME
SMOKE UP IN THE STRATOSPHERE,
ANALOGOUS TO VOLCANOES.
WELL, YOU CAN MAYBE CONSIDER
DOING THAT IF THE PROBLEM IS
GONNA LAST FOR ONLY A CENTURY.
BUT IF IT'S GONNA LAST FOR
10,000 YEARS, YOU KNOW, WE CAN'T
SIGN FOR THAT.
THAT'S TOO MUCH.
SO IT'S NOT JUST ME THAT SAYS
THAT THE CO2 HAS THIS LONG
LIFETIME.
IT'S NOT A DIFFICULT
CALCULATION, ACTUALLY.
THESE ARE ALL MODEL STUDIES THAT
I'VE SEEN OR REVIEWED.
THIS IS ALL OF THEM, I'M NOT
HIDING ANY OF THEM FROM YOU.
AND IT'S NOT REALLY A DIFFICULT
CALCULATION.
I COULD SHOW YOU JUST WITH SOME
THERMODYNAMICS AND A PIECE OF
PAPER WHY THERE'S THIS--
WHY ALL THE CO2 DOESN'T DISSOLVE
IN THE OCEANS, FOR EXAMPLE.

A new table shows different projections of the CO2 peak, and its prognosis for 1 thousand years and 100 thousand years.

David continues BUT JUST TO LOOK AT THESE
DIFFERENT MODELS, YOU SEE IN THE
CO2 PEAK SOMETHING LIKE 50 percent TO
70 percent OF THE CARBON THAT WE
RELEASE OVER THE WHOLE TIME
PERIOD THAT WE'RE RELEASING CO2
WILL BE IN THE ATMOSPHERE AT THE
TIME OF THE PEAK.
OF COURSE, THAT DEPENDS ON THE
TIMING.
IF YOU RELEASED IT ALL, YOU
KNOW, IN AN INSTANT, THEN THAT
NEXT INSTANTLY WOULD ALL BE IN
THE ATMOSPHERE.
THIS DEPENDS ON RELEASING IT
OVER, YOU KNOW, A FEW--
OVER DECADES AND A FEW
CENTURIES.
BUT THEN, THE TALE COMES IN
HERE.
AFTER A THOUSAND YEARS, YOU
STILL HAVE 30 percent, 40 percent OF THE CO2
THAT WAS RELEASED STILL IN THE
ATMOSPHERE, AFTER 10,000 YEARS
YOU STILL HAVE 10 percent, 15 percent, 20 percent,
SOMETHING LIKE THAT.
SO IT DOESN'T ALL JUST GO AWAY.

A new slide with line charts compares the current release of CO2 with a natural release from the past.

David continues AND THEN HERE IS A RECORD OF A
CLIMATE EVENT FROM THE GEOLOGIC
PAST THAT ALSO CORROBORATES THIS.
THIS IS AN EVENT THAT HAPPENED
55 MILLION YEARS AGO CALLED THE
PALAEOCENE-EOCENE THERMAL
MAXIMUM.
SO WE ARE GOING FROM HERE TO
THERE IN TIME, LEFT TO RIGHT.
THIS PLOT, IF I FLIP THEM, YOU
HAVE TO CHECK TO SEE WHICH WAY
TIME IS GOING.
PALEO CLIMATE, PEOPLE HAVE THIS
WEIRD THING I DON'T UNDERSTAND.

[Audience laughter]

David continues UH, SO WE'RE
GOING ALONG AND EVERYTHING'S
KIND OF FINE.
AND THEN THERE'S THIS SPIKE OF
CO2 THAT'S RELEASED TO THE
ATMOSPHERE AND IT'S NOT CLEAR
WHERE THAT COMES FROM.
IT'S ACTUALLY--
WE DON'T HAVE DIRECT
MEASUREMENTS OF CO2 BECAUSE
THERE ARE NO ICICLES THAT GO
BACK THAT FAR.
THIS IS ACTUALLY A MEASUREMENT
OF THE ISOTOPIC COMPOSITION OF
C13 AND CALCIUM CARBONATE, WHICH
TELLS US ABOUT CO2...
IF YOU WANT TO HEAR IT, I CAN GO
INTO IT, BUT YOU CAN JUST TAKE
MY WORD FOR IT.
THIS IS SORT OF A CO2 PROXY.
CO2 SPIKES UP, TEMPERATURE
SPIKES UP, AND BOTH OF THEM
RECOVER BACK ON A TIME SCALE OF
ABOUT 100,000 YEARS.
SO IT DOESN'T GO AWAY IN 100
YEARS, IT LASTS FOR MUCH LONGER
THAN THAT.

A new table shows the average temperature increase for different amounts of coal burnt.

David continues SO IF WE ASSUME 3 DEGREES C
FOR, UH--
AS A NUMBER CALLED THE THE
CLIMATE SENSITIVITY, THAT'S HOW
MUCH YOU WARM THE PLANET IN
EQUILIBRIUM IF YOU DOUBLE THE
CO2 CONCENTRATIONS.
THAT WAS THE NUMBER THAT SVANTE
ARRHENIUS CALCULATED AND HE GOT
ABOUT THE SAME, MAYBE HE GOT 4
DEGREES.
HE GOT 4 TO 6 DEGREES C FOR
THAT.
BUT IF WE ASSUME 3 DEGREES C,
WHICH IS KIND OF A STANDARD
MODEL RESULT THESE DAYS, THEN WE
CAN FIGURE OUT THE TEMPERATURE
CHANGE GOING INTO THE DEEP
FUTURE, 1,000 YEARS OR 10,000
YEARS INTO THE FUTURE, DEPENDING
ON HOW MUCH CARBON WE ULTIMATELY
RELEASE.
SO THESE UNITS HERE ARE PROBABLY
ESOTERIC TO YOU.
THAT UNIT IS GIGATONNES, WHICH
MEANS BILLION METRIC TONNES, AND
TO GIVE YOU AN IDEA OF THE
FOSSIL FUELS, MOST OF THE FOSSIL
CARBON IS IN THE FORM OF COAL.
THERE'S MUCH MORE COAL, LIKE 50
TIMES MORE COAL THAN THERE IS
OIL OR NATURAL GAS.
AND 5,000 GIGATONNES IS SORT OF
A STANDARD ESTIMATE FOR HOW MUCH
TRADITIONALLY MINEABLE COAL
THERE IS.
SO THIS BOTTOM-LINE IS IF WE GO
TO TOWN AND BURN ALL THE COAL.
THAT WOULD TAKE SEVERAL
CENTURIES.
2,000 GIGATONNES IS JUST A
LITTLE BIT MORE THAN THE
BUSINESS'S USUAL SCENARIO TO THE
YEAR 2100.
SO, YOU KNOW, THIS IS SORT OF A
MODERATE BURN AND THIS IS A
LARGE BURN.
AND SO YOU GET THESE TEMPERATURE
CHANGES OF 3 DEGREES, 5 DEGREES
LOOKING OFF INTO THE FUTURE.
SO WHY IS THAT IMPORTANT?
WELL, ANOTHER LESSON WE CAN
LEARN FROM THE PAST IS THAT SEA
LEVEL IS VERY RESPONSIVE TO
GLOBAL TEMPERATURE.

A new chart shows the sea level at different points in Earth’s history.

David continues SO THIS IS A PLOT OF THE
TEMPERATURE OF THE EARTH ON THIS
AXIS RELATIVE TO TODAY AND, ON
THE VERTICAL AXIS, IS THE SEA
LEVEL.
AND SO, WHEN YOU MAKE A BIG ICE
SHEET, THE OCEAN LEVEL DROPS
BECAUSE YOU PUT ALL THE WATER IN
THE ICE.
AND SO THE LAST GLACIAL MAXIMUM
TIME, 20,000 YEARS AGO,
TEMPERATURE WAS ABOUT 6 DEGREES
COLDER THAN TODAY AND THE SEA
LEVEL WAS 120 METRES LOWER.
THE PLIOCENE 3 MILLION YEARS
AGO, THAT WAS BEFORE WE HAD ICE
IN THE NORTHERN HEMISPHERE, LIKE
GREENLAND.
AND THE SEA LEVEL WAS MAYBE 20,
25 METRES HIGHER AND THE
TEMPERATURE WAS SOMEWHAT WARMER.
THIS IS AN ICE FREE STATE 40
MILLION YEARS AGO, BEFORE THERE
WAS ICE EVEN IN ANTARCTICA.
AND IF YOU WERE TO MELT ALL THE
ICE TODAY, YOU WOULD GET ABOUT
70 METRES OF SEA LEVEL RISE.
SO THERE'S THIS CORRELATION
BETWEEN TEMPERATURE AND SEA
LEVEL IN THE PAST.
OKAY, NOW IN RED, YOU SEE THE
IPCC FORECAST FOR THE COMING
CENTURY, WHICH IS AS WE'VE SAID
NOW A COUPLE OF TIMES, 3 DEGREES
C OF WARMING GLOBALLY AND THEY
FORECAST THE SEA LEVEL RISE TO
BE A HALF A METRE OR ONE METRE
OF SEA LEVEL RISE.
WHICH IS TOTALLY OFF OF THAT
HISTORIC LINE AND THE REASON WHY
IT'S OFF IS BECAUSE IT TAKES A
LONG TIME TO MELT AN ICE SHEET
AND IT TAKES A LONG TIME ALSO TO
WARM UP THE DEEP OCEAN.
SO SOME OF THE SEA LEVEL RISE IN
THE FORECAST FOR THE COMING
CENTURY IS JUST BECAUSE OF THE
THERMAL EXPANSION OF THE WATER,
AND BOTH OF THOSE PROCESSES TAKE
TIME.
BUT WE HAVE TIME.
IF WE STICK TO A MODERATE CARBON
BURN, WE GET 3 DEGREES OF
WARMING FOR 1,000 YEARS.
AND IF WE GO TO TOWN ON ALL OF
THE COAL, WE CAN KEEP THE 3
DEGREES GOING FOR 10,000 YEARS.
SO, YOU KNOW, IF WE HAVE ALL THE
TIME THAT WE NEED TO MELT AN ICE
SHEET, THEN WE'RE TALKING ABOUT
VASTLY MORE SEA LEVEL RISE THAN
WHAT'S FORECAST FOR THE COMING
CENTURY.
NOW WE'RE NOT
GONNA BE AROUND IN 1,000 YEARS
OR 10,000 YEARS.
I'M NOT ARGUING THAT WE SHOULD
BASE OUR DECISION-MAKING PROCESS
IN THE HERE AND NOW ON SOMETHING
THAT'S HAPPENING IN 10,000 YEARS
RATHER THAN SENSIBLY WORRYING
ABOUT WHAT'S HAPPENING IN THE
NEXT 100 YEARS.
BUT JUST FOR
THE SAKE OF CURIOSITY, I'M JUST
SHOWING YOU WHAT HAPPENS ON THE
LONGER TIME FRAME.
WELL, AND YOU CAN ALSO MAKE THE
CASE THAT THE MODELS THAT WERE
USED TO FORECAST THE SEA LEVEL
RISE ARE TOO SLUGGISH BECAUSE
THERE ARE ALL KINDS OF THINGS
THAT HAPPENED IN THE PAST WHICH
THE MODELS CAN'T REPRODUCE.
THERE'S A NEW IPCC REPORT COMING
OUT IN 2007, WHICH DOESN'T HAVE
THAT ERROR IN TABLE 1 ANYMORE.
I CAN VOUCH FOR THAT, I BELIEVE.
BUT IT STILL BASES THE SEA LEVEL
RISE FORECAST ON MODELS.
YOU KNOW, I MEAN, YOU CAN'T
REALLY FAULT THEM FOR THAT, WHAT
ELSE ARE YOU GONNA DO?
AND THERE'S A VERY CLEAR, YOU
KNOW, CAVEAT IN THE REPORT THAT
SAYS THAT, WELL, THE REALITY
YOU KNOW, YOUR MILEAGE MAY VARY
ESSENTIALLY.
THE REALITY MAY BE GREATER THAN
THIS BECAUSE MODELS, YOU KNOW,
MAY BE TOO SLUGGISH.

A new slide shows a drawing of an ice sheet and a sun.

David continues BUT FOR WHAT IT'S WORTH, THE WAY
AN ICE SHEET WORKS IS IF IT'S
COLD DOWN AT THE BASE OF THE ICE
SHEET AND THE ICE IS ACTUALLY
FROZEN TO THE ROCK, THE ICE
SHEET WILL BE VERY SLUGGISH AND
IT WON'T MOVE BY VERY MUCH.
AND SO AN ICE SHEET, YOU CAN
MAKE AN ICE SHEET MOVE IN A
MODEL IF YOU HEATED THE SURFACE
AND THEN THE HEAT HAS TO DIFFUSE
DOWN THROUGH THE ICE, AND IT
TAKES THOUSANDS OF YEARS TO
AFFECT THE BED, WHICH IS WHERE
THE ACTION IS.
BUT THE REAL GREENLAND ICE
SHEET, WE SEE FLUCTUATIONS IN
THE FLOW RATE OF THE ICE SHEET
IN THE SUMMER VS. THE WINTER.
THE REAL ICE SHEET CAN RESPOND
TO WARMING IN A COUPLE OF
MONTHS, NOT 1,000 YEARS AND THE
IDEA IS--
THE THOUGHT IS THAT IT'S BECAUSE
MELT WATER, WATER THAT MELTS AT
THE SURFACE, IS SOMEHOW ABLE TO
GO ALL THE WAY THROUGH THIS ICE
SHEET AND THEN LUBRICATE THE BED
AT THE BOTTOM.
AND NOBODY REALLY UNDERSTANDS
HOW THIS CAN HAPPEN BECAUSE IT'S
COLDER THAN FREEZING DOWN INSIDE
THAT ICE SHEET AND SO, YOU KNOW,
WE WOULD EXPECT THE WATER TO
FREEZE ON THE WAY DOWN.

A picture shows a hole in a blueish ice sheet and water pouring down into it.

David continues BUT HERE'S A PICTURE OF WATER
FLOWING DOWN INTO THE GREENLAND
ICE SHEET.
IT'S CALLED A MOULIN.
THIS PICTURE IS NOW--
IT WAS ON THE COVER OF
SCIENCE
A FEW WEEKS AGO
AND IT'S NOW KIND OF REACHED
ICONIC--
YOU'LL PROBABLY SEE THIS ON
T-SHIRTS, YOU KNOW, VERY SOON,
THIS PICTURE.

[Audience laughter]

A new slide shows several charts and graphs with information about earthquakes in Iceland.

David continues THERE ARE
MEASURABLE EARTHQUAKES AROUND
THE EDGE OF GREENLAND, WHICH ARE
ATTRIBUTED TO THE ICE MOVING
AGAINST THE ROCK.
AND YOU SEE--
SO THERE'S TWO DIFFERENT KINDS
OF EARTHQUAKES IN THE PLOTS.
THE GREY ONES ARE NON-GLACIAL
EARTHQUAKES, SO THOSE ARE JUST
SORT OF GARDEN-VARIETY GENERIC
EARTHQUAKES, AND THEN THE GREEN
ONES ARE GLACIAL EARTHQUAKES,
THE ONES WHERE THE ICE IS
FLOWING.
AND YOU SEE THAT THEY ACCELERATE
IN THE SUMMER, AND YOU SEE ALSO
THAT THEY HAVE BEEN ACCELERATING
THROUGH TIME.
SO HERE'S 2000 AND HERE'S 2005.
SO THERE'S BEEN THIS
ACCELERATION OF THE RUMBLING OF
THE GREENLAND ICE SHEET.
THERE ARE EVENTS IN THE PAST
WHICH CAN'T BE EXPLAINED BY THE
ICE SHEET MODELS ALSO.
ONE CLASS OF THESE EVENTS ARE
CALLED HEINRICH EVENTS, NAMED
AFTER A SEDIMENT OCEANOGRAPHER
NAMED HEINRICH, WHO DISCOVERED
THESE LAYERS OF ROCKS IN HIS
SEDIMENT COURSE FROM THE NORTH
ATLANTIC.
SO THESE ARE BIG ROCKS.
THEY'RE THINGS THAT YOU COULDN'T
CARRY AROUND IN THE WIND.
THEY COULDN'T BE WIND-BLOWN.
THE ONLY WAY TO GET THEM THERE
WAS AS--
CARRY THEM, IS IN ICEBERGS.
SO THE ONLY WAY TO MAKE A HUGE
LAYER OF THESE THINGS ALL THE
WAY ACROSS THE ATLANTIC, AS FAR
SOUTH OF SPAIN, IS TO HAVE THE
LAURENTIDE ICE SHEET JUST
COLLAPSE WITHIN A CENTURY OR SO,
SPAWNING WHAT THEY CALL AN
ARMADA OF ICEBERGS, WHICH THEN
DROP THESE ROCKS ALL OVER THE
PLACE.

A new slide titled “Heinrich events, 30 to 70 thousand years ago” shows a drawing of how the chunks of ice left the sheet carrying debris.

David continues THEY ARE THOUGHT TO HAVE RAISED
SEA LEVEL BY MAYBE 5 METRES IN A
CENTURY OR A FEW CENTURIES, AND
WE DON'T REALLY UNDERSTAND HOW
THESE WORKED.
WE CAN'T MAKE A MODEL DO THIS
AND SO, YOU KNOW, WE COULDN'T
POSSIBLY FORECAST IF GREENLAND
WAS GONNA START DOING IT.
WE COULD TELL YOU THAT, IF IT
DOES START, THERE'S NO WAY WE
COULD STOP IT BUT WE CAN'T TELL
YOU WHETHER IT'S LIKELY OR NOT.

A new slide reads “Meltwater pulse 1A 19 thousand years ago.”

David continues THERE WAS A TIME INTERVAL DURING
THE END OF THE LAST ICE AGE,
WHEN THE ICE SHEETS, THE
LAURENTIDE ICE SHEET WAS
MELTING, SORT OF GOING FROM THE
GLACIAL MAXIMUM TO TODAY.
IT'S RIGHT HERE.
IT'S CALLED MELT WATER PULSE 1A.
AND THIS WAS A SEA LEVEL RISE OF
25 METRES OR SO, 20, 25 METRES
WITHIN ONE TO FIVE CENTURIES.
SO, YOU KNOW, THAT'S A HUGE SEA
LEVEL RISE.
WE CAN'T EVEN TELL YOU THERE'S
STILL DISPUTE ABOUT WHERE THIS
WATER CAME FROM, WHICH ICE SHEET
IT WAS THAT DID IT.
WE CAN'T TELL YOU, YOU KNOW, HOW
IT DID IT.
WE DON'T--
YOU KNOW, THE MODELS DON'T DO
SO, YOU KNOW, THAT'S A HUGE SEA
LEVEL RISE.
WE CAN'T EVEN TELL YOU THERE'S
STILL DISPUTE ABOUT WHERE THIS
WATER CAME FROM, WHICH ICE SHEET
IT WAS THAT DID IT.
WE CAN'T TELL YOU, YOU KNOW, HOW
IT DID IT.
WE DON'T--
YOU KNOW, THE MODELS DON'T DO
THIS.
SO JUST TO SHOW YOU WHAT THIS
LOOKS LIKE, MY--
ACTUALLY, MY 12-YEAR-OLD SON
SHOWED ME HOW TO PASTE IMAGES
INTO GOOGLE EARTH.
I DON'T KNOW IF YOU'VE PLAYED
WITH GOOGLE EARTH YET BUT--

[Audience laughter]

David continues YOU SHOULDN'T
INSTALL IT ON YOUR COMPUTER
UNTIL YOU'VE GOT A LONG, RAINY
WEEKEND AHEAD OF YOU BECAUSE
YOU'LL JUST PLAY WITH IT FOR
HOURS AND HOURS.

A map shows the eastern coast of U.S.A. painted in red, with the caption “20 metres.”

David continues SO WHAT HE SHOWED ME HOW TO DO
WAS TO PASTE IN AREAS WHERE--
THAT ARE WITHIN 20 METRES OF SEA
LEVEL, AND SO I COULD JUST LOOK
AROUND THE GLOBE AND SEE THIS.
AND IT TURNS OUT THAT ONE OF THE
PLACES THAT'S--
ONE OF THE BIG HEADLINE PLACES
ON THE EARTH THAT GETS HARD-HIT
IS SORT OF THE EAST AND GULF
COASTS OF THE U.S.
FLORIDA, YOU SEE, KIND OF GETS
IT FROM BOTH SIDES.

A new map shows northern Europe with the lowlands painted in red.

David continues ANOTHER IS THE LOW COUNTRIES OF
EUROPE, HOLLAND AND DENMARK, MOSTLY.

A new map shows the same for China.

David continues AND THEN THERE'S THIS RIVER
DELTA IN CHINA, AND IT'S
ASTONISHING THAT THE POPULATION
OF CHINA IS SO MUCH HIGHER THAN
IT IS OF THE U.S. OR CANADA, NOT
BECAUSE IT'S SUCH A VAST
COUNTRY, BUT BECAUSE IT'S JUST
REALLY CROWDED.
THE DENSITY IS HUGE.
AND THIS WHOLE REGION HERE WHICH
IS WITHIN 20 METRES OF SEA LEVEL
CUTS RIGHT INTO THE HEART OF THE
POPULATION DENSITY OF THE
PLANET, REALLY.
SO I WANTED TO GO ON NOW AND
TELL YOU ABOUT THE PROGRESSION
OF ICE AGES ON EARTH AND HOW THE
FOSSIL FUEL CO2 KIND OF COMPARES
WITH THAT.
SO WE DON'T REALLY UNDERSTAND
VERY WELL THE PROGRESS OF ICE
AGES.
WE KNOW THAT IT'S CORRELATED IN
TIME TO VARIATIONS IN THE
EARTH'S ORBIT AND, IN
PARTICULAR, THAT THE INTENSITY
OF SUNLIGHT IN THE NORTHERN
HEMISPHERE SUMMER SEEMS TO BE
VERY IMPORTANT.
SO, WHEN THE ORBIT IS SUCH THAT
YOU GET A REALLY HOT SUN IN THE
NORTHERN HEMISPHERE SUMMER--
SO, IN OTHER WORDS, WHEN THE
SUMMER, NORTHERN HEMISPHERE
SUMMER HAD A PART OF THE EARTH'S
ORBIT THAT'S CLOSE TO THE SUN,
THE ICE SHEETS MELT.
AND WHEN IT'S COLD IN THE
NORTHERN HEMISPHERE SUMMER, YOU
DON'T--
YOU GROW THE ICE SHEETS.
THE SUMMER IS WHAT'S IMPORTANT
BECAUSE IT'S ALWAYS COLD ENOUGH
TO SNOW IN THE WINTER, RIGHT?
BUT IN THE SUMMERTIME, IF IT'S
TOO WARM, THEN YOU MELT THE SNOW
AND YOU GOT TO START OVER AGAIN
NEXT WINTER AND YOU DON'T MAKE
AN ICE SHEET.
WHEREAS IF IT'S COOL IN THE
SUMMER, THE SNOW CAN KIND OF
ACCUMULATE AND START TO MAKE AN
ICE SHEET.
BUT THERE ARE ALL KINDS OF
DETAILS THAT ARE NOT VERY WELL
UNDERSTOOD.
SO WHAT I'M GONNA SHOW YOU IS
BASED ON SORT OF A 3-STATE MODEL
BY A FRENCH GUY NAMED DIDIER
PAILLARD.
AND WE'RE ONLY INTERESTED IN ONE
PART OF THIS.

He walks up to the giant screen and shows a chart with three apexes captioned “Interglacial state,” “unstable glacial,” and “glacial.”

David continues WE START FROM AN INTERGLACIAL
STATE LIKE WE'RE IN NOW AND IF
THE SUMMER SUNLIGHT AT 65
DEGREES NORTH DROPS BELOW A
THRESHOLD AND WE'RE IN THIS
STATE, THEN YOU FLIP TO THAT
STATE.
SO YOU NUCLEATE AN ICE SHEET.

A new chart shows the changes before and after the ice ages.

David continues AND SO THIS IS HIS SORT OF
IDEALIZED SEQUENCE OF ICE AGES,
SO HERE IS THE ICE VOLUME.
HERE IS THE PRESENT-DAY, HERE'S
THE LAST GLACIAL, AND HERE'S THE
LAST INTERGLACIAL, AND SORT OF
GOING BACK AND FORTH.
SO THE INTERGLACIALS ARE
GENERALLY THESE DARK SPLOTCHES
HERE, AND THEN HERE IS
PAILLARD'S PROGRESSION FROM
INTERGLACIAL TO GLACIAL.
AND HE MAKES THE CASE THAT, YOU
KNOW, THE TRANSITIONS LINE UP
PRETTY WELL.
HERE IS THE SUNLIGHT FORCING AND
THE NORTHERN HEMISPHERE SUMMER,
AND WHEN IT DROPS BELOW THIS
THRESHOLD, THAT'S WHEN YOU GO
FROM AN INTERGLACIAL TO A
GLACIAL TIME.
SO THIS IS THE
TRIGGER THAT WE'RE GOING TO LOOK
AT, IS THE SUMMER SUNLIGHT
INTENSITY AT 65 NORTH.
SO WE CAN GET THIS SAME KIND OF
TRIGGER BEHAVIOUR IN A CLIMATE
MODEL.

A complex graph pops up.

David continues WHAT WE DID IN
THIS MODEL IS WE STARTED OUT
WITH AN ORBIT THAT GUARANTEED
THAT THERE WAS A WARM SUMMER
SUNSHINE AT THE BEGINNING OF THE
MODEL RUN AND WE SLOWLY TURNED,
CHANGED THE ORBIT SO THAT THE
NORTHERN HEMISPHERE SUMMERS
WOULD GET COLDER AND COLDER AND
THEN, ALL OF A SUDDEN, BLAM!
THEY NUCLEATED AN ICE SHEET AT
A SORT OF TRIGGER VALUE OF THE
SUNLIGHT INTENSITY.
AND THEN WE KEEP GETTING COLDER
AND COLDER AND THE ICE SHEET
SORT OF GROWS, AND THEN WHEN YOU
GO BACK WARMER AGAIN, YOU CAN--
YOU OVERSHOOT.
BECAUSE ONCE THE ICE SHEET IS
THERE, IT REFLECTS SUNLIGHT AND
SO IT SORT OF STABILIZES ITS OWN
EXISTENCE.
THIS IS THAT ICE ALBEDO FEEDBACK
AGAIN THAT ARRHENIUS DISCOVERED.

New charts appear on the screen.

David continues SO NOW SETTING THE STAGE FOR
THIS CALCULATION, WE'VE GOT CO2
IN THE TOP PANEL.
SO HERE ARE THE GLACIAL,
INTERGLACIAL CYCLES OF
ATMOSPHERIC CO2 CONCENTRATION,
AND THEY DON'T LOOK VERY
DRAMATIC THERE BECAUSE THEY'RE
KIND OF SQUISHED TOGETHER
BECAUSE I'VE ALSO SUPERIMPOSED
THE FUTURE TRAJECTORIES OF
ATMOSPHERIC CO2 CONCENTRATION,
GIVEN DIFFERENT SIZES OF THE
FOSSIL FUEL RELEASE, THE SLUG
THAT WE RELEASE.
AND REMEMBER 5,000 GIGATONNES OF
CARBON, THAT WAS BASICALLY ALL
OF THE COAL.
AND THEN, ON THE SECOND PART OF
THE PLOT, WE HAVE THE SUNLIGHT
INTENSITY AT 65 NORTH IN THE
SUMMER AGAIN, AND THEN THE GREEN
LINE HERE IS THE CRITICAL
TRIGGER VALUE.
AND SO, ACCORDING TO PAILLARD'S
MODEL, WE ARE IN INTERGLACIAL
STATES WHENEVER, YOU KNOW, WHERE
THERE'S A GREEN DASH HERE.
THOSE ARE PAILLARD'S
INTERGLACIAL TIMES.
SO YOU SEE WHERE WE ARE AT THE
PRESENT IS RIGHT THERE, AND THE
SUNLIGHT AT THE NORTHERN
HEMISPHERE SUMMER IS ACTUALLY
GETTING RATHER CLOSE TO THE
CRITICAL TRIGGER VALUE.
SO THERE'S ALL KINDS OF DISPUTES
IN THE SCIENTIFIC LITERATURE
ABOUT WHETHER THE NEXT ICE AGE
IS SORT OF COMING IN THE NEXT
1,000 YEARS OR SO, OR WHETHER
IT'S NOT GONNA COME UNTIL SORT
OF THE NEXT TIME AROUND THERE,
WHICH IS ABOUT 50,000 YEARS INTO
THE FUTURE.
YOU SEE THAT THE VARIATION IN
THE SUNLIGHT INTENSITY IS NOT AS
EXTREME IN THE NEAR FUTURE AS IT
WAS 20,000 YEARS AGO AND THAT'S
BECAUSE THE CONFIGURATION OF THE
EARTH'S ORBIT IS CURRENTLY SUCH
THAT IT DOESN'T--
IT'S NEARLY CIRCULAR NOW AND SO
IT DOESN'T--
YOU DON'T GET THE VARIATIONS IN
THE INTENSITY OF THE SUNLIGHT.
I WOULD SAY THAT THIS IS SORT OF
A TOO-CLOSE-TO-CALL KIND OF
RESULT.
WE DON'T KNOW THE CRITICAL
TRIGGER THAT WELL TO BE ABLE TO
SAY, YOU KNOW, WHO'S RIGHT AND
WHO'S WRONG IN A NATURAL WORLD,
WHETHER THE NEXT ICE AGE WOULD
COME, YOU KNOW, IN THE NEXT
1,000 YEARS, 2,000 YEARS, OR
MAYBE NOT UNTIL 50,000 YEARS
FROM NOW.
BUT THIS CRITICAL TRIGGER IDEA
OF PAILLARD'S, THIS WAS BASED ON
THE NATURAL CO2 CONCENTRATION IN
THE NATURAL ATMOSPHERE DURING A
NORMAL INTERGLACIAL TIME, WHICH
WAS ABOUT 280 PARTS PER MILLION.
WHAT IT WAS, YOU KNOW, OUR
INTERGLACIAL UNTIL ABOUT THE
YEAR 1750 WHEN IT STARTED GOING UP.
SO, IN THIS MODEL THAT PREDICTED
THIS, THAT GOT THE SAME SORT OF
TRIGGER BEHAVIOUR, WE RAN THE
SAME THING AGAIN WITH DIFFERENT
CO2 CONCENTRATIONS.
AND WE FOUND THAT THE VALUE OF
THE TRIGGER WHERE THE ICE SHEET
SUDDENLY FORMED DEPENDS ON HOW
MUCH CO2 IS THERE.
SO IF YOU HAVE MORE CO2 IN THE
AIR THAT KIND OF WARMS THINGS
UP, AND SO YOU HAVE TO HAVE A
DEEPER CUT IN THE SUNLIGHT
INTENSITY IN ORDER TO MAKE THAT
ICE SHEET START.
SO HIGHER CO2 VALUES AND A LOWER
VALUE OF THIS CRITICAL TRIGGER
SUNLIGHT INTENSITY.
FEWER WATTS PER METRE SQUARED OF
SUNLIGHT.
SO IF WE TAKE THE CO2
TRAJECTORIES FOR THE FUTURE HERE
AND WE RUN THEM THROUGH THAT
LAST RELATIONSHIP WITH THE
CRITICAL TRIGGER VALUE, THIS IS
WHAT HAPPENS TO THE TRIGGER IN
THE FUTURE.
IT GOES, YOU KNOW, WAY DOWN LIKE
THAT SO THAT IT'S--
IF, YOU KNOW, WE WERE TO BURN
5,000 GIGATONNES OF CARBON,
WE'RE NOW WAY OUTSIDE OF THE
RANGE OF ORBITAL SUNLIGHT
INTENSITY VARIATIONS AND WE
COULD AVOID ANOTHER ICE AGE FOR
HALF A MILLION YEARS, SOMETHING
LIKE THAT.
IT'S A REALLY DEEP TIME IMPACT.

Coloured bars pop up on the chart.

David continues SO HERE, WE SEE THE INTERGLACIAL
PERIODS.
THE MODEL'S SAYING THAT WE
WOULD'VE STAYED AN INTERGLACIAL
FOR 50,000 YEARS ANYWAY
ALTHOUGH, LIKE I SAID BEFORE,
IT'S SORT OF TOO CLOSE TO CALL.
1,000 GIGATONNES OF CARBON
PROLONGS IT UNTIL WHAT IS THIS,
130,000 YEARS AND 5,000
GIGATONNES OF CARBON, LIKE I
SAY, HALF A MILLION YEARS.
AND THEN HERE'S SORT OF A CRUDE
ESTIMATE OF EARTH'S TEMPERATURE.
IT JUST SHOWS THAT THE EFFECTS
OF RELEASING CO2 NOW CAN PERSIST
INTO THE GEOLOGIC FUTURE.
NOW I ALSO LIVE IN A PLACE THAT
USED TO BE COVERED WITH A MILE
OF ICE.
CHICAGO IS NOT THAT FAR FROM
HERE.
AND SO I'D BE THE LAST ONE TO
ARGUE THAT WE NEED TO SAVE THE
NEXT ICE AGE.
THE NEXT ICE AGE WOULD PROBABLY
NOT BE GOOD FOR, YOU KNOW, MY
REAL ESTATE VALUES OR YOURS
EITHER.
BUT I GUESS I WOULD SAY THAT
THIS SHOWS THAT WE HAVE NOW SORT
OF TAKEN THE REINS OF THE
CLIMATE OF THE PLANET, OR AT
LEAST WE HAVE THE POTENTIAL TO
IF WE BURN ALL OF THE COAL.
AND THAT NATURAL COOLING IS
UNLIKELY TO BE ABLE TO COME IN
AND SORT OF SAVE US FROM
OURSELVES.
YOU MAY BE WONDERING, WELL, WHY
DO WE CARE?
AND I CAN'T ANSWER THAT.
YOU KNOW, WE WON'T BE AROUND IN
10,000 YEARS SO, IN ANY
PRACTICAL SENSE, WE HAVE
ABSOLUTELY NO REASON TO CARE
ABOUT SOMETHING THAT'S THAT FAR
INTO THE FUTURE.
ON THE OTHER HAND, WE ALSO HAVE
NO PRACTICAL REASON TO CARE
ABOUT THE LONGEVITY OF NUCLEAR
WASTE.
YOU KNOW, IF IT LASTS 10,000
YEARS, WHAT'S THE DIFFERENCE TO
US IF IT LASTS 100 YEARS?
IT'S ALL THE SAME, WE'RE NOT
GONNA BE AROUND ANYWAY.
AND YET, PEOPLE DO SEEM TO CARE.
IT DOES SEEM TO BE--
I THINK IF, YOU KNOW, NUCLEAR
WASTE WAS SHOWN TO BE JUST A
100-YEAR SORT OF PHENOMENON,
PEOPLE MIGHT FEEL DIFFERENTLY
ABOUT IT.
AND I PERSONALLY FEEL
DIFFERENTLY ABOUT, YOU KNOW,
FILLING UP MY GAS TANK WITH
GASOLINE AND PUTTING IT INTO THE
AIR GIVEN THAT a quarter OF WHAT I
RELEASE IS GONNA BE AFFECTING
CLIMATE FOR, YOU KNOW, THE AGE
OF HUMAN CIVILIZATION.
I DUNNO, IT GETS TO ME SOMEHOW.
I DON'T KNOW WHY.

[Audience laughter]

David continues SO, TO END ON
AN UP BEAT INSTEAD OF A DOWN
BEAT, WHAT IS THERE TO DO?
WE HAVE ALREADY EMITTED ABOUT
300 GIGATONNES OF CARBON FROM
FOSSIL FUELS AND FROM
DEFORESTATION.
SO THAT'S THE SAME UNIT, 300
VERSUS THE 5,000 IS ALL OF THE
COAL.
I AND MY COLLABORATORS CALCULATE
THAT WE COULD ULTIMATELY EMIT--
A FUZZY NUMBER BECAUSE WE DON'T
KNOW EVERYTHING PERFECTLY--
BUT ULTIMATELY ABOUT 700 OF
THOSE SAME UNITS TO JUST BARELY
AVOID WHAT THEY CALL A DANGEROUS
CLIMATE CHANGE OF 2 DEGREES C.
NOW THOSE ARE
SORT OF FIGHTING WORDS,
DANGEROUS CLIMATE CHANGE,
BECAUSE SOME PEOPLE WILL ATTACK
YOU FOR SAYING, YOU KNOW, FOR
IMPLYING THAT ANYTHING LESS THAN
2 DEGREES C IS SAFE, WHICH I
WOULDN'T DO OR--
SAYING THAT 2 DEGREES C, I MEAN,
THAT'S, YOU KNOW, IT'S 2 DEGREES
C COLDER OUT THERE NOW THAN IT
WAS THIS MORNING.
YOU CALL THAT DANGEROUS?
IT'S SORT OF A PERSONAL--
I MEAN, IT'S A JUDGMENT CALL, IS
WHAT IT IS.
BUT 2 DEGREES C
WOULD WARM THE PLANET MORE THAN
HAS BEEN SEEN IN MILLIONS OF
YEARS AND SO THAT SEEMS LIKE A
REASONABLE DISCUSSION POINT
ABOUT WHAT WE CONSIDER TO BE
DANGEROUS.
SO IF WE SAY THAT 2 DEGREES C IS
A DANGEROUS CLIMATE CHANGE BASED
ON THE HISTORY TO TEMPERATURE,
BASED ON HISTORY OF SEA LEVEL,
STUFF LIKE THAT THAT I'VE SHOWN
YOU, WE CALCULATE THAT WE
COULD EMIT ABOUT AS MUCH
CARBON, MAYBE A LITTLE MORE, AS
HAS ALREADY BEEN DONE AND JUST
BARELY AVOID EXCEEDING THAT
DANGER LIMIT.
SO THE 400 GIGATONNES THAT WE
HAVEN'T RELEASED YET THAT WE
COULD CONCEIVABLY RELEASE
WITHOUT PASSING THAT DANGER
LIMIT IS ABOUT EQUIVALENT TO THE
REST OF THE PETROLEUM AND THE
NATURAL GAS DEPOSITS.
COAL IS REALLY THE BIG FOSSIL FUEL.
COAL IS WHERE THE THOUSANDS OF
GIGATONNES ARE.
SO WE COULD BURN ALL THE--
LOOKS TO ME LIKE WE COULD BURN
ALL OF THE OIL AND THE GAS AND
JUST STOP BURNING COAL, AND THAT
WOULD PROBABLY JUST ABOUT DO IT.
NOT SO EASY TO DO, OBVIOUSLY,
BUT WHEN YOU PUT IT THIS WAY, IT
DOESN'T SOUND SO BAD, RIGHT?
OKAY, SO THANK YOU VERY MUCH.

[Long applause]

Now a slate reads “Questions and answers.”

David and a man in his fifties sit on stools on the stage.

The man holds a microphone and says
YOU SAID STOP BURNING COAL.
LET'S IMAGINE IN THE REAL WORLD
WHEREIN YOU ARE ELECTED
PRESIDENT OF THE UNITED STATES
AND I'LL GIVE YOU BOTH HOUSES OF
CONGRESS AS WELL.

David says WOW!

[Audience laughter]

The man continues SO HERE--
BUT EVERYTHING ELSE IS REAL.
WE'RE STILL IN 2006, WE STILL
HAVE A REAL ECONOMY, WE STILL
HAVE REAL RESTRAINTS...

David says YEAH, YEAH,
YEAH.

The man continues AND SO FORTH.
WHAT--
THIS IS--

David says HOW DO YOU STOP
BURNING COAL.

The man continues WHAT SHOULD WE DO?

David says WELL, YOU CAN
BURN IT OR THERE ARE OTHER
THINGS YOU CAN DO WITH IT TO
EXTRACT ENERGY.
THERE'S A TECHNOLOGY CALLED
INTEGRATED GASIFICATION COMBINED
CYCLE, WHICH TREATS THE COAL.
IT'S STEAM AND PRODUCES HYDROGEN
AND CARBON MONOXIDE, WHICH--
AND THE CARBON MONOXIDE CAN BE
BURNED TO GET ENERGY FROM IT,
AND IT GIVES YOU A STREAM OF
PURE CO2, WHICH IS THEN MUCH
MORE EASY TO CAPTURE AND YOU CAN
SEQUESTER IT DOWN IN THE EARTH.
THERE'S ALL THESE PLACES, UH,
SALINE AQUIFERS.
THEY'RE SORT OF SANDSTONE LAYERS
FOLDED WITH SALTY WATER THAT
NOBODY WOULD EVER WANT ANYWAY,
THE IDEA.
SO YOU COULD JUST SQUIRT CO2
DOWN IN THERE AND--
I MEAN, IT SOUNDS DANGEROUS
BECAUSE WHAT IF IT CAME BACK
OUT, THAT WOULD BE BAD.
BUT ON THE OTHER HAND, THERE'S
METHANE NATURAL GAS THAT'S BEEN
DOWN IN THE EARTH FOR MILLIONS
OF YEARS, SO IT'S NOT INFEASIBLE
THAT IT COULD BE DONE.
SO IT COSTS MORE TO BUILD AN
IGCC PLANT AND THEY'RE STILL
SORT OF EXPERIMENTAL AND
TEMPERAMENTAL AND--
YOU KNOW, IT'S NOT LIKE FALLING
OFF A LOG, THE WAY BUILDING A
COAL-FIRED POWER PLANT IS.
BUT IF YOU BURN COAL, WHAT YOU
GET IS A MIXTURE OF 80 percent NITROGEN
AND THEN 20 percent CO2.
SO YOU HAVE TO SEPARATE THE CO2
OUT AND IT COSTS ENERGY TO DO
THAT.
AND SO, IF YOU ACTUALLY BUILD
INTO YOUR ASSUMPTIONS WHEN
YOU'RE MAKING THE DECISION THAT
YOU WANT TO SEQUESTER THE
CARBON, IT'S CHEAPER TO GO WITH
THE NEW TECHNOLOGY THAN TO GO
WITH THE OLD.
AND YET, IN THE U.S., WE ARE
GOING BANANAS BUILDING NEW
COAL-FIRED POWER PLANTS.
THERE ARE 160, 158, SOMETHING
LIKE THAT, NEW PLANTS THAT ARE
EITHER BEING BUILT OR THAT ARE
ON, YOU KNOW, IN THE PLANNING
STAGES OF BEING BUILT.
AND THESE THINGS ARE GOOD FOR 50
YEARS.
SO, YOU KNOW, INVESTING IN
BUILDING THESE THINGS NOW IS
JUST--
IT SEEMS FOOLISH.
SO THAT'S ONE THING THAT WE
COULD DO RIGHT NOW.

The man says RIGHT.

David says I MEAN, WHETHER
WE COULD--
TO MAKE THE CO2 CONCENTRATION IN
THE ATMOSPHERE STOP GOING UP, WE
WOULD HAVE TO CUT OUR EMISSIONS
BY ABOUT HALF.
AND, IN THE U.S., WE ALREADY ARE
BURNING TWICE AS MUCH CARBON PER
PERSON AS TWO PEOPLE IN EUROPE
OR JAPAN.
WE'RE ALREADY TWICE--
I MEAN, YOU KNOW, WE SHOULD CUT
BY HALF ANYWAY AND--
JUST TO BE ON A PAR WITH THOSE
OTHER PLACES.
BUT GLOBALLY THE EMISSIONS HAVE
TO BE CUT BY HALF, WHICH MEANS
THAT IN A PERFECTLY, YOU KNOW,
FAIR WORLD WHERE EVERY PERSON
WAS RELEASING THE SAME AMOUNT OF
CO2, THE AVERAGE CITIZEN OF THE
U.S. WOULD HAVE TO CUT BY 90 percent.
AND THIS IS THE REAL WORLD,
THAT'S NOT GONNA HAPPEN
OVERNIGHT.
BUT AT LEAST WE COULD START
GOING IN THE RIGHT DIRECTION BY
DEVELOPING THESE NEW
TECHNOLOGIES RATHER THAN SORT OF
GOING FOR THE DINOSAUR OPTION
AND TRYING TO GRANDFATHER AGAIN.

The man says SURE.

David continues SO ONE EXAMPLE
I LIKE TO THINK OF IS TELEPHONES
IN ISRAEL, FOR EXAMPLE, OR IN
INDIA.
THEY NEVER INSTALLED LANDLINES
IN LOTS OF PLACES.
THEY LEAPFROGGED BECAUSE, IN THE
MEANTIME, WE DEVELOPED CELL
PHONES AND, YOU KNOW, THAT WAS A
MUCH CHEAPER THING FOR THEM TO
ADOPT, AND SO THEY JUST MOVED
RIGHT TO THE GOOD STUFF,
WELL, THE SAME THING COULD
HAPPEN WITH ENERGY.
WE COULD, YOU KNOW--
WE GOT A LOT OF SMART PEOPLE.
WE COULD DEVELOP THESE
TECHNOLOGIES TO NOT RELEASE CO2
AND GET ENERGY, EITHER FROM IGCC
OR FROM WINDMILLS, OR--
I'VE HEARD ALL KINDS OF GREAT
IDEAS FOR REALLY BIG ENERGY
PAYOFF.
SOLAR CELLS ON THE MOON, I HEARD
A TALK ONCE.

The man says RIGHT.

David says WE BEAM THE
ENERGY BACK TO THE EARTH IN
MICROWAVES.
YEAH, THAT WAS GREAT, I LOVED
THAT.

[Audience laughter]

David continues UH...
WE COULD START DOING THAT, YOU
KNOW.
IF WE TOOK IT UPON OURSELVES AS
A CHALLENGE, WE COULD DO THAT
AND THEN THE DEVELOPING WORLD
WOULD BE ABLE TO SORT OF
LEAPFROG OVER THE DESTRUCTIVE
TECHNOLOGY THAT WE'VE BEEN
INDULGING IN.

The man says WHEN YOU TALK ABOUT THE
ECONOMICS, OFTEN, PEOPLE TEND TO
BE OVERLY DESPAIRING AND THEY
GIVE UP.
BUT THERE ARE SOLID ECONOMIC
ARGUMENTS AS TO HOW TO GO
FORWARD, AND THERE'S A SOLID
ECONOMIC FRAMEWORK TO BE ABLE TO
SPECIFY THE PROBLEM.
IN YOUR BOOK, YOU MENTION THE
TRAGEDY OF THE COMMON
CATEGORIZATION OF THE PROBLEM
WHICH MAYBE YOU CAN SPEAK TO FOR
JUST A MINUTE.
AND YOU ALSO MENTION THIS NOTION
OF CAPPING AND TRADE--
CAP AND TRADE AS A WAY OF BEING
ABLE TO SOMEHOW DEAL ON A
WIDESPREAD LEVEL WITH THIS
PARTICULAR ISSUE, AND THERE ARE
PRECEDENTS OF THAT HAVING BEEN
QUITE SUCCESSFUL WITH ACID RAIN
AND SO FORTH.
SO PERHAPS YOU COULD SPEAK A
LITTLE BIT ABOUT THAT AS WELL.

David says WELL, THE
TRAGEDY OF THE COMMONS IS THE
SITUATION WHERE A PERSON WHO
BENEFITS FROM MAKING A DECISION
DOESN'T PAY THE COSTS OF IT.
SO A FARMER BUYS ONE MORE SHEEP
TO GRAZE ON THE COMMON YARD IN
THE VILLAGE CENTRE AND THAT
AFFECTS THE PRODUCTIVITY OF ALL
THE OTHER FARMERS AND THEIR
SHEEP, YOU KNOW.
THEY ALL SUFFER.
SO EVERYBODY PAYS THE COST OF
THAT SHEEP BUT ONLY ONE PERSON
GETS THE BENEFIT.
AND SO, THE INCENTIVE OF EACH
INDIVIDUAL FARMER IS TO PUT AS
MANY SHEEP ONTO THE COMMONS AS
POSSIBLE BECAUSE HE'S NOT PAYING
THE COST.
AND THAT, IN ECONOMICS, IS
CALLED AN EXTERNAL COST 'CAUSE
IT'S EXTERNAL TO THE GUY THAT'S
MAKING THE DECISION.
SO ONE WAY TO AVOID THAT IS TO
DIVIDE THE COMMONS UP INTO
LITTLE PIECES AND SAY, OKAY,
BOB, YOU GET THIS PIECE, AND
JANE, YOU GET THAT PIECE.
AND SO YOU PUT ANOTHER SHEEP ON
THERE AND IT DOESN'T AFFECT
ANYBODY BUT YOU.
YOU OWN THAT PIECE OF LAND NOW,
AND SO THAT COST IS NOT EXTERNAL
ANYMORE, IT'S INTERNAL, AND IT
CAUSES YOU TO BE A BETTER
STEWARD OF THE LAND.
THE ATMOSPHERE, YOU CAN'T REALLY
DIVIDE IT UP INTO OWNERSHIP THAT
WAY SO, BECAUSE IT, YOU KNOW, IT
FLOWS AROUND AND IF WE RELEASE
CO2 HERE, IT AFFECTS THE CLIMATE
IN CHINA.
IF THEY RELEASE IT THERE, IT
AFFECTS OUT HERE.
SO THE OTHER ALTERNATIVE IS,
WELL, SOME SORT OF REGULATION
GASP, HATE TO SAY IT.
SOME SORT OF--

The man says YOU CAN SAY IT.

David says COMMUNAL--
WELL, THAT'S RIGHT.
I'M NOT IN THE U.S. ANYMORE.

The man says YOU CAN SAY IT IN THIS
COUNTRY, THAT'S RIGHT.

[Audience laughter]

David continues IT'S SO
REFRESHING, I LOVE IT HERE.
SO YOU SET A LIMIT, YOU PUT A
TAX ON EMITTING CARBON, SO
YOU'RE TAKING THE EXTERNAL COST
AND YOU'RE MAKING THE PERSON WHO
MAKES A DECISION PAY THAT COST.
SO THAT'S A LESSON FROM
ECONOMICS.
ANOTHER IS THAT...
IF THE ECONOMY IS GROWING AT
SOME RATE PER YEAR, SAY IT'S
GROWING AT 3 percent A YEAR, AND THEN
YOU CAP--
YOU PUT A TAX ON IT OF 3 percent EVERY
YEAR BECAUSE YOU HAVE TO GET
YOUR ENERGY FROM AN IGCC PLANT,
WHICH IS A LITTLE MORE
EXPENSIVE, OR WINDMILLS OR
SOMETHING, THAN, YOU KNOW, CHEAP
BURNING OF COAL, THOSE ARE
DIFFERENT 3 PERCENTS.
SO IT'S NOT LIKE THE GROWTH RATE
THEN GROWS FROM 3 percent TO BEING 0.
SO YOU TAKE 3 percent EVERY YEAR OFF
AND WHAT THAT MEANS IS IF THE
GROWTH TRAJECTORY IS EXACTLY
WHAT IT WOULD'VE BEEN BUT JUST
DELAYED BY ONE YEAR--
SO, SAY, WE WOULD'VE HAD 100 dollars
THIS YEAR, 103 dollars NEXT YEAR, BUT
NOW WE'VE GOT TO PAY 3 dollars EVERY
YEAR TO THE CLEAN ENERGY
FACTORY, THEN WE GOT 97 dollars THIS
YEAR, 100 dollars NEXT YEAR.
SO WE HAVE 100 dollars JUST A YEAR LATER.
AND THEN THE OTHER LESSON FROM
ECONOMICS THAT YOU MENTIONED WAS
THIS IDEA OF TRADING EMISSIONS,
WHICH--
I MEAN, IT SOUNDS ODIOUS.
YOU BUY THE RIGHT TO POLLUTE.
BUT WHAT IT ACTUALLY DOES IS IT
SHIFTS THE COST--
THE CUTTING OF THE EMISSIONS TO
WHOMEVER CAN DO IT THE MOST
CHEAPLY.
SO IF YOU'VE GOT SOME BIG POWER
PLANT THAT'S EMITTING HUGE
AMOUNTS OF CO2 AND FOR, YOU
KNOW, 10 dollars YOU CAN MAKE IT STOP
EMITTING THAT CO2, AND THEN
THERE'S ANOTHER PLANT OVER THERE
THAT WOULD COST 100 dollars TO DO THE
SAME THING, THE WAY IT'LL WORK
IS YOU'LL DO THE CUTTING LOCALLY
WHERE IT'S CHEAP, AND THEN
YOU'LL SELL THE PERMITS TO THE
OTHER GUY FOR, YOU KNOW, 50 dollars OR
SOMETHING.
SO YOU'LL MAKE MONEY AND HE'LL
SAVE MONEY OFF OF MAKING THE
CUTS THERE.
AND SO THIS WAS DONE IN THE U.S.
TO REGULATE ACID RAIN, WHICH
ACTUALLY, THERE'S A LITTLE BIT
OF A PROBLEM THAT CAN ARISE IF
YOU--
THAT ALL THE ACID RAIN BE
EMITTED FROM ONE PLACE, IT'LL
STILL HAVE A BAD IMPACT RIGHT AT
THAT PLACE.
SO YOU SORT OF WANT TO SPREAD IT
OUT, IDEALLY, WHICH CAP AND
TRADE DOESN'T DO BY ITSELF BUT
CO2 IS PERFECT FOR THAT BECAUSE
IT DOESN'T MATTER WHERE IT'S
RELEASED, IT'S A GLOBAL ISSUE.
AND THE RESULT WITH ACID RAIN IN
THE U.S. WAS THAT IT CUT THE
EMISSIONS AT A FAR CHEAPER PRICE
THAN ANYBODY HAD DARED HOPE.
FOR THE CAP AND TRADE WITH
KYOTO, IT SEEMS LIKE IT'S HAVING
KIND OF GROWTH PAINS THAT THE
COST OF THE PERMITS THAT GET
TRADED DEPEND VERY SENSITIVELY
ON HOW MANY OF THEM ARE
ALLOCATED.
SO HOW AMBITIOUS YOU MAKE THE
CUTS.
AND IT--
AND LITTLE CHANGES IN THE
ALLOCATION HAVE CAUSED THESE
HUGE SPIKES AND GYRATIONS IN THE
COSTS OF THOSE CO2 EMISSIONS
PERMITS.
AND THEN THE FACT THAT THE WHOLE
THING IS COMING TO AN END IN
2012 MEANS THAT, IF YOU'RE NOT
CERTAIN WHAT'S GONNA HAPPEN,
MAYBE INSTEAD OF MAKING SOME
CAPITAL INVESTMENT TO YOUR POWER
PLANT THAT WILL CUT YOUR
EMISSIONS FOR, YOU KNOW, 30
YEARS INTO THE FUTURE THAT WOULD
COST A LOT OF MONEY NOW, MAYBE
IT'D BE SAFER TO YOUR
STOCKHOLDERS OR WHATEVER TO JUST
BUY THE EMISSIONS TRADES CREDITS
FROM SOMEWHERE ELSE.
SO THE FACT THAT THE WHOLE THING
WINDS DOWN SOON IS UNDERMINING A
LITTLE BIT THE LONG-TERM
EFFECTIVENESS, IS MY
UNDERSTANDING.
ANOTHER LESSON FROM ECONOMICS
THAT TIES IN HERE IS THAT IF YOU
MAKE A CHANGE SORT OF GRADUALLY,
IT'S A LOT CHEAPER THAN MAKING
IT IN AN EMERGENCY WAY ALL AT
ONCE.
SO IF WE STOP BUILDING THESE BIG
POWER PLANTS AND THEN, YOU KNOW,
TEARING THEM DOWN--

The man says RIGHT.

David says YOU KNOW, THEN
HAVING LATER TO TEAR THEM DOWN
AND BUILD SOMETHING NEW, BUT
RATHER REPLAN AHEAD, WE CAN DO
IT MORE CHEAPLY.
AND I THINK IT CAN BE DONE.

The man says THANK YOU VERY MUCH.
AND ON THAT OPTIMISTIC NOTE, I'D
LIKE TO THANK YOU ONCE AGAIN FOR
A VERY STIMULATING LECTURE.

David says OKAY, THANK YOU.

[Long applause]

The clip ends and Andrew reappears in the studio with a caption that reads “Andrew Moodie.”

He says FASCINATING,
ISN'T IT?
SWEDISH CHEMIST SVANTE
ARRHENIUS CALLED IT IN 1896.
THE WORLD
STARTED TO LISTEN IN 2006.
110 YEARS, THAT'S NOT BAD AS FAR
AS EVOLUTIONARY HISTORY GOES.
IT'S HARD NOT TO GET A LITTLE
DEPRESSED ABOUT ARCHER'S DATA.
ARCHER MADE A STAB AT OPTIMISM
AT THE END OF THE LECTURE,
SUGGESTING THAT WE CAN BURN ALL
THE OIL WE WANT AS LONG AS WE
STOP BURNING COAL.
I WOULD ADD THAT IT TOOK ABOUT A
CENTURY TO GET THE PLANET INTO
THIS STATE.
THAT'S A BLIP OF TIME IN THE
GRAND SCHEME OF THINGS.
WHAT WE CAN DO IN THE NEXT 100
YEARS TO CLEAN IT UP?
WELL, I'LL TELL YOU WHAT I'M
GOING TO DO.
I'M GOING TO STOP USING
NEWSPRINT.
I'VE HAD A WONDERFUL
RELATIONSHIP WITH IT ALL MY LIFE
BUT IT'S OVER.
WE NEED THE TREES NOW MORE THAN
EVER.
AND THERE WILL BE NO PAPER
INVOLVED, IN CASE YOU WANT TO
REQUEST INFORMATION ABOUT
UPCOMING PROGRAMS ON
BIG
IDEAS.
SEND US AN E-MAIL AT
bigideas@tvo.org AND EVERY
FRIDAY YOU'LL RECEIVE AN UPDATE.
FOR
BIG IDEAS, I'M ANDREW
MOODIE.

[Theme music plays]

The end credits roll.

bigideas@tvo.org

416-484-2746

Big Ideas. Producer, Wodek Szemberg.

Producers, Lara Hindle, Mike Miner, Gregg Thurlbeck.

Logos: Unifor, Canadian Media Guild.

A production of TVOntario. Copyright 2007, The Ontario Educational Communications Authority.

Watch: David Archer