Trace Gas Chemistry in the Cities and Over the Oceans
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ErdrutschMeeting/Interview
00:51
DecompositionErdrutschPlant breedingSet (abstract data type)StickstoffdioxidIslandIce frontLecture/ConferenceMeeting/Interview
01:16
ColourantMoleculeGasUmweltchemikalieAreaWursthülleLipopolysaccharideLecture/ConferenceMeeting/Interview
01:41
DecompositionComposite materialWursthülleStickstoffdioxidThermoformingStickstoffoxideRiver sourceSea levelStickstoffatomOzoneLecture/ConferenceMeeting/Interview
02:06
Composite materialGasSea levelCarbon dioxideMethanisierungPeriodateLecture/ConferenceMeeting/Interview
02:30
StickstoffoxideSpeciesConcentrateHydroxylController (control theory)Lecture/ConferenceMeeting/Interview
02:55
MagnetometerLecture/ConferenceMeeting/Interview
03:20
Stainless steelMoleculeLecture/ConferenceMeeting/Interview
03:45
ConcentrateMoleculeStainless steelMethanisierungSample (material)Lecture/ConferenceMeeting/Interview
04:10
MethanisierungRiver sourceCarbon (fiber)Radioactive decayLecture/ConferenceMeeting/Interview
04:35
River sourceLactitolMethanisierungLecture/ConferenceMeeting/Interview
05:00
Cell growthMethanisierungPeriodateAgeingLecture/ConferenceMeeting/Interview
05:25
MethanisierungConcentrateInitiation (chemistry)GasLecture/ConferenceMeeting/Interview
05:50
EtherHydroxybuttersäure <gamma->OzoneSeparation processLecture/ConferenceMeeting/Interview
06:14
OzonePhotochemistrySeparation processChemistryLecture/ConferenceMeeting/Interview
06:39
ThermoformingPhotochemistryOzoneSatellite DNAPeriodateComposite materialPlant breedingLecture/ConferenceMeeting/Interview
07:04
OzoneLecture/ConferenceMeeting/Interview
07:29
EtherRiver sourceCarbon monoxideHydrocarbonLecture/ConferenceMeeting/Interview
07:54
DecompositionCarbon monoxideStickstoffatomHydrocarbonStickstoffoxideMoleculeOxygenLecture/ConferenceMeeting/Interview
08:19
HydrocarbonWine tasting descriptorsStickstoffoxideFireRiver sourceIsotropyAreaAbundance of the chemical elementsComposite materialLecture/ConferenceMeeting/Interview
08:44
Angular milOzoneSetzen <Verfahrenstechnik>AreaLecture/ConferenceMeeting/Interview
09:09
OxygenStickstoffatomStickstoffoxideHuman body temperatureLecture/ConferenceMeeting/Interview
09:33
DecompositionCalcium hydroxideCatalytic converterStickstoffoxideSunscreenFunctional groupHuman body temperatureGasLecture/ConferenceMeeting/Interview
09:58
EtherPotenz <Homöopathie>GasStickstoffoxideHuman body temperatureConcentrateLecture/ConferenceMeeting/Interview
10:23
ConcentrateEthaneMoleculeSample (material)PropionaldehydHydrocarbonSeparation processGas chromatographyZunderbeständigkeitAageBreed standardLecture/ConferenceMeeting/Interview
10:48
Sample (material)Azo couplingPropionaldehydConcentrateHydrocarbonEthaneMoleculeSeparation processLecture/ConferenceMeeting/Interview
11:13
ChemistryConcentrateLeft-wing politicsLecture/ConferenceMeeting/Interview
11:38
Lecture/ConferenceMeeting/Interview
12:03
ConcentrateCarbon dioxideCarbon monoxidePlant breedingPoppersLecture/ConferenceMeeting/Interview
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PoppersCarbon monoxideAcetyleneCarbon dioxideChemical compoundConcentrateCardiac arrestLecture/ConferenceMeeting/Interview
12:52
OceanPropionaldehydAcetyleneCarbon monoxideConcentrateButyraldehydeLecture/ConferenceMeeting/Interview
13:17
MagmaPropionaldehydPetroleumButyraldehydeAgeingLecture/ConferenceMeeting/Interview
13:42
DibromethaneBleitetraethylOzoneTetrachloroethyleneMoleculeEthyleneElectronic cigaretteSolventLecture/ConferenceMeeting/Interview
14:07
EtherHydroxybuttersäure <gamma->MoleculeSystemic therapyFireLecture/ConferenceMeeting/Interview
14:32
OceanUmweltchemikalieFireAgricultureBurnLecture/ConferenceMeeting/Interview
14:57
Radioactive decayRiver sourceEmission spectrumLecture/ConferenceMeeting/Interview
15:22
Radioactive decayRiver sourceConcentrateAreaLecture/ConferenceMeeting/Interview
15:47
BurnAreaFireConcentrateSmoking (cooking)StickstoffoxideLecture/ConferenceMeeting/Interview
16:12
Coast ProvinceFireStickstoffatomLecture/ConferenceMeeting/Interview
16:36
ChemistTrace elementAtomic orbitalBurnSmoking (cooking)AgricultureNeotenyAreaLecture/ConferenceMeeting/Interview
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NeotenySatellite DNAOzoneLecture/ConferenceMeeting/Interview
17:26
EtherOzoneBurnRiver sourceLecture/ConferenceMeeting/Interview
17:51
DecompositionChemistrySetzen <Verfahrenstechnik>FireLecture/ConferenceMeeting/Interview
18:16
FireFunctional groupLecture/ConferenceMeeting/Interview
18:41
Trace elementComposite materialHydrocarbonElektrolytische DissoziationStickstoffoxideOzoneNickelFireFunctional groupBurnLecture/ConferenceMeeting/Interview
19:06
DecompositionFunctional groupStickstoffoxideOzoneBurnSea levelFireLecture/ConferenceMeeting/Interview
19:31
Trace elementCarbon monoxideBurnCarbon (fiber)ÖlIslandLecture/ConferenceMeeting/Interview
19:55
DecompositionBurnCarbon monoxideConcentrateIsotropyLecture/ConferenceMeeting/Interview
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ChemistryMoleculeMolecular beamOzoneNanoparticleLecture/ConferenceMeeting/Interview
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ChemistryOzoneLecture/ConferenceMeeting/Interview
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Breed standardOzoneComposite materialMaterials scienceLecture/ConferenceMeeting/Interview
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ErdrutschMaterials scienceOzoneUmweltchemikalieLecture/ConferenceMeeting/Interview
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OzoneLecture/ConferenceMeeting/Interview
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Lecture/ConferenceMeeting/Interview
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SunscreenLecture/ConferenceMeeting/Interview
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OperonLecture/ConferenceMeeting/Interview
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Cell growthLecture/ConferenceMeeting/Interview
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DeceptionGum arabicUmweltchemikalieLecture/ConferenceMeeting/Interview
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UmweltchemikalieDeceptionAreaLecture/ConferenceMeeting/Interview
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LactoseAreaLecture/ConferenceMeeting/Interview
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Death by burningBurnLecture/ConferenceMeeting/Interview
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BurnCarbon dioxideComposite materialSunscreenPhotosynthesisAageProcess (computing)DecompositionLecture/ConferenceMeeting/Interview
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EtherSunscreenCarbon dioxideBurnCharcoalLecture/ConferenceMeeting/Interview
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Hydro TasmaniaCarbon dioxideStadtgasPotenz <Homöopathie>River sourceÖlLecture/ConferenceMeeting/Interview
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WettingCarbon dioxideIce frontRiver sourceLecture/ConferenceMeeting/Interview
27:23
DecompositionGermanic peoplesZunderbeständigkeitBreed standardLecture/ConferenceMeeting/Interview
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PeriodatePressureLecture/ConferenceMeeting/Interview
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SubstitutionsreaktionBreed standardCarbon (fiber)Lecture/ConferenceMeeting/Interview
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PressureCarbon dioxideLecture/ConferenceMeeting/Interview
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Lecture/ConferenceMeeting/Interview
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OzoneTrace elementReaktionsgleichungNew Millennium ProgramLecture/ConferenceMeeting/Interview
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EtherAnomalie <Medizin>UmweltchemikalieLecture/ConferenceMeeting/Interview
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Lecture/ConferenceMeeting/Interview
30:42
NobeliumComputer animation
Transcript: English(auto-generated)
00:21
Andrea is heading back to handle the slides. Countess Bernadotte, fellow scientists. What I want to talk about today fits rather closely with what Paul has talked about. It's a situation I think that Paul and Mario
00:42
and I have been in for much of the last 20 years that our work keeps interacting in ways that have been profitable for all of us. If we're ready, the first slide. Now we need some lights down.
01:03
This is a slide taken in Southern California looking out towards Santa Catalina Island, which is back behind there. What one sees across in front of that is a brown line. That brown line is nitrogen dioxide coming from Los Angeles.
01:22
I live south of Los Angeles. We produce our own gases as well, but in this particular case, this pollution is from Los Angeles. It's only in polluted areas that you really see colored gases because the existence of color means
01:41
that the molecule can be absorbing visible radiation, and that usually breaks it up. In the particular case of nitrogen dioxide, it also breaks it up, but it reacts to form nitrogen oxide and that reacts with ozone to reform it, so it's constantly being made there, and that's why you see this as a characteristic of smog.
02:03
I will now be looking at some of the same things that Paul did, and that is the composition of the atmosphere in which what one sees is that down to the level of one part and 10 to the ninth, there aren't many things that you can see.
02:20
All of these gases are relatively stable. The amounts of carbon dioxide and methane, as you've heard, are changing, but other than that, this is the way the atmosphere with small changes has been for a long period of time. However, when you can get down to looking at concentrations that are very much lower,
02:43
down in the range of 10 to the minus 11 for nitrogen oxide and the brown NO2, and even down below that for hydroxyl, then you see the reactive species that control much of what's going on in the atmosphere, and the ability to understand what's going on
03:03
down in this range has depended upon the development of instrumentation that allows you to be able to make measurements there. Now, you did hear from Paul that we have been making, you heard, rather, in the introduction that we've been making measurements around the world, especially in the Pacific.
03:22
This is right at the beginning in 1978, and I'm holding here a canister in which it's evacuated in the laboratory. You take it to a remote location, and you proceed to fill it and bring it back to the laboratory and see what was there. This was on a trip.
03:41
The picture was taken by my wife. It was before we were funded for any of this kind of work. The canister itself is shown here. It's a stainless steel canister evacuated in the laboratory and returned for analysis of what's in it. One of the molecules that we started measuring immediately,
04:02
that we had those samples, was methane, as you heard from Paul. The concentration which we measured in 1978 was about 1.6 parts per million in the northern hemisphere, a little bit less than 1.5 parts per million in the southern hemisphere.
04:21
The sources of this are mostly biological. We know that from the radioactivity, the carbon-14 radioactivity, in the methane in the atmosphere. Cattle are a source. The average cow produces half a pound of methane per day, and there are 1.3 billion cows in the world,
04:42
and that makes it an important source. Rice paddies are another source, and so on. But the important aspect of this is that if you continue to make measurements of methane, as shown here, 1978 to 1986, we move ahead eight years or so, and instead of 1.6, one finds 1.75,
05:03
and in the southern hemisphere, instead of being down around 1.5, it was up over 1.6. So there's been a steady growth in the amount of methane in the atmosphere in that time period, starting in 1978 and running up to here. We're now up at around 1,750 parts per parts
05:22
in 10 to the ninth, where we started at 1,520, and where, in the pre-industrial age, the number was around 700. So there's been a very substantial increase in the amount of methane in the atmosphere, especially during the latter part of the 20th century.
05:41
But that's not the only gas that's been changing in concentration. And the initial measurements of tropospheric ozone that were made at a place called Montserrat, which was outside Paris, and this is a 20-year average from 1870 to 1890. And the characteristic that one can see
06:02
in the amount of ozone present at that time, more than a century ago, was that it was about the same throughout the year, from January to December, had essentially the same amount of ozone, and the amount was at the order of 10 parts per billion. Several 20th century, late 20th century measurements are shown here,
06:22
one of them being Hohen-Peisenberg that you already heard about from Paul. And what you see is two things that have changed. One is that the total amount of ozone is larger in every season, but it's much larger in the summer. And this is because of the photochemical production of ozone, which is favored by the sunlight
06:42
of the summer and the greater humidity. You get more ozone production at that time. So this has been a major change in the composition of the atmosphere over the period of time of one century, from low ozone here to being seasonally dependent with a lot of photochemical ozone being formed.
07:01
One can see this in a dual satellite measurement, which you subtract one from the other and you get the tropospheric ozone. And what you see is across, during May and June, across the entire northern hemisphere, between 25 and 50 degrees north, the red indicating higher amounts of ozone,
07:21
but you see a band of high ozone in which most of the developed world lives. And so this is a characteristic that we think is only something of the late 20th century and that wasn't there in the 19th. And one of the major causes is shown by looking at this, that you have major traffic problems
07:42
and traffic is a source of tropospheric ozone. And if I summarize again what Paul had talked about, these are the three characteristics that one needs for making tropospheric ozone. You need hydrocarbons or carbon monoxide.
08:02
You need the nitrogen oxides and you need sunlight. And you get the nitrogen oxides by heating ordinary air, which is nitrogen and oxygen, in the presence of some catalyst like your carburetor that will convert the N2 and O2 into two molecules of NO.
08:20
That gives you the nitrogen oxides. The hydrocarbons come from unburned or partially burned gasoline, and in parentheses I've indicated that you don't have to have it coming from traffic. If you burn wood and get partial decomposition, you can also get hydrocarbons.
08:41
Hot fires can produce nitrogen oxides and of course the tropics are an abundant source of sunlight. And what we have found, the tropospheric ozone in Los Angeles was found around 1950. And at that time it was suggested that maybe it was some special characteristic
09:00
of the area around Los Angeles that made it susceptible to having ozone formation. What we found out in the last four decades is that it doesn't really make much difference where as long as you have a lot of traffic, then you'll get tropospheric ozone. And that's now a characteristic of cities all over the world.
09:22
The equilibrium between nitrogen and oxygen and nitrogen oxide is one which is always in favor of the nitrogen and oxygen. But if you can set up the equilibrium, the amount of nitrogen oxide that's in equilibrium with the N2 and O2 is very different
09:41
depending on the temperature. And you can see that it doesn't change the amount of N2 and O2 in the first two significant figures, but the amount of NO has gone up by a factor of 10 to the 10th in this range. And the function of the catalytic converter in your carburetor on your automobile
10:00
is to take the gases that have already been burned and have been given you the power and have produced a certain amount of nitrogen oxide and then you convert them back to some equilibrium at a lower temperature that has less nitrogen oxide in it. And that was one, of course, one of the major advantages in trying to keep down the nitrogen oxide concentration of the atmosphere.
10:23
We're looking here at SMOG at the Eiffel Tower in Paris. We were measuring the concentrations of hydrocarbons in Paris a few years back. And this is a standard technique that we use called gas chromatography,
10:42
in which the time goes on this axis and the time identifies the individual molecule and the concentration goes on this axis and several of them here are off scale. But you'll see molecules in here like ethane and propane and a number of hydrocarbons.
11:03
And this sample was taken on the top of the Eiffel Tower at midnight. And here was a sample taken a couple of days later down in the traffic. And you can see in the midst of traffic you'll get very intense concentrations of hydrocarbons, all of which contribute then to the chemistry
11:20
of the atmosphere there. This is a picture of Santiago, Chile. It's actually a picture taken from a postcard. This is the way it looks on occasion. I want to call your attention to the existence of a major traffic artery that runs from the lower left to the upper right in this picture
11:41
because I'm going to come back to that in a minute. This is the look of Santiago much of the time because they now have very bad smog problems. And so with the aid of about 40 students from the Catholic University of Santiago,
12:01
we had them all over Santiago with empty canisters at five o'clock in the morning and then again at nine o'clock in the morning. And so we have a before and after the major traffic pattern for Santiago. And this is what we saw now. The major artery runs, again, as I indicated across here,
12:22
the red indicates higher concentrations of carbon monoxide. And so what we see at five o'clock that there was a little bit higher carbon dioxide here which is down sloped from during the night. And then in the four hours in between during the rush hour, there's a tremendous amount of carbon monoxide
12:40
that's put into the atmosphere in Santiago. And that surely then is a contribution from traffic. But we measured a very large number of compounds at the same time and two different kinds are shown here. This is acetylene or ethyne and it looks very much like carbon monoxide. That the concentration was a little bit higher at five o'clock
13:01
and then the traffic pattern gets superimposed on it. And that's because acetylene is one of the major products coming out of the traffic in the morning. On the other hand, we have a gas like propane which was there at five o'clock and it was there at nine o'clock and doesn't look as though there's much difference. And the reason for that is
13:20
that propane is not associated with traffic. Propane and the two butanes are associated with liquefied petroleum gas which is what's used for heating and cooking in many cities and certainly in Santiago also in Mexico City where we saw similar effects. And this is simply leakage of liquefied petroleum gas
13:42
and that's taking place all the time and that becomes a major contributor to the ozone problems in Santiago and Mexico City and elsewhere. And then you have molecules like perchloroethylene here which is a cleaning solvent not associated with traffic and ethylene dibromide which is a molecule
14:01
put in with leaded gas and which was still in use in Santiago. And again, you see the traffic pattern of this molecule leaking out there. So we have a lot of information out of experiments like this that tell us which things are coming from traffic and which things are coming from other aspects of the environment.
14:21
What you're looking at here are the Petronas Towers in Kuala Lumpur in Malaysia. They are the two tallest buildings in the world and this is what they look like occasionally and this is what they looked like last August when the fires with Indonesia and where it was sufficiently bad in Malaysia
14:43
that the government of Indonesia apologized to the government of Malaysia for the fact that their air pollution there was so bad and it was coming from the burning of agricultural wastes primarily in Indonesia. And this, now we're looking at a space shuttle photograph of Western Europe
15:04
and what you can see, what you're really looking at is the nighttime emission of radiation in the visible region. And this is what it looks like and you can pick out all of the major cities of Western Europe here because that's the major source of that radiation being picked up from outside.
15:23
But if you take it on a global basis then you can ask a question in the same way. What is the source of all this radiation? Well, something like 90% of this radiation comes from the cities just as you saw with Western Europe. But here in Africa and over here in South America
15:42
and in occasional places in Australia, you see substantial amount of light being emitted from areas in which there are no concentration of large cities. And that's the biomass burning that Paul was talking about before. This is a photograph taken in Botswana. This is a fire that was 60 miles, 100 kilometers long.
16:04
It burned for a week and so you could see a huge amount of material would have been burned in that time producing smoke, producing hydrocarbons, producing nitrogen oxides. This is taken from the space shuttle looking northward from Namibia over Angola.
16:22
So you're on the west coast of Africa in the southern hemisphere in the tropics and you're looking north and what you can see is that fires are just everywhere. It is a very common practice for clearing off the agricultural waste to burn them off in preparation for the next year. And so you see huge amounts there.
16:41
This is taken from the space shuttle in September over Brazil and you can see from the curvature that this is a very large area. It's in fact all of Brazil. It's the equivalent of the entire eastern half of the United States was covered by a smoke cloud coming again from the burning of agricultural wastes
17:02
and from forests. This is World Cup time and if you're going to, this is a Brazilian child or a young Brazilian, he's kicking a soccer ball despite the fact that September smog was there. If that's the way it is, you've still got to practice.
17:22
Now if I go back to this dual satellite picture here, what one sees is that as you, now again we're looking at tropospheric ozone and now it's September and October and this indicated there was a substantial amount of ozone out here over the South Atlantic
17:42
and the obvious logical source for this was biomass burning and so in 1992 there were two programs, one of them called SAFARI and Paul showed some of the results from that. SAFARI was largely a European investigation but at the same time there was a US investigation
18:01
based on the NASA DC-8 to see what the chemistry was that was going on in the formation of this tropospheric ozone. Here is a fire map for September of 1992 when the airplane was flying and these are the fires that were seen in Africa at that time and so there's a lot of fires
18:21
in Namibia and Angola and Zambia there. The aircraft that we were using is the NASA DC-8. It is equipped, it's a flying laboratory and maybe 10 or 12 different research groups will be on it. This is Don Blake, my colleague in there, an undergraduate working with us
18:42
and this is our air intake. We bring the air into the airplane and inside the airplane we have a large number of the canisters which we have here and this is Senior Research Associate Nicola Blake filling these canisters and again we send them back for analysis to see what the hydrocarbon composition was
19:02
and what we found was by comparing our hydrocarbon measurements and other people's nitrogen oxide measurements and the ozone measurements from still another group that yes, it was biomass burning that was producing that extra tropospheric ozone. About two-thirds of it was coming from the fires
19:20
in Africa and blowing out at low level and some of it was coming back from Brazil coming in at high level and so it was a substantial amount of increase in tropospheric ozone that could be attributed directly to this burning. Now in 1996 we were flying in the Pacific with two airplanes and this was just on a flight
19:42
from Guayaquil in Ecuador to the Galapagos Islands and this is the entire flight along here and this is just carbon monoxide measurements and the carbon monoxide in the background should have been somewhere down around like that but you can see on that flight which lasted for a number of hours that about half the time they were running
20:02
into high carbon monoxide concentrations instead of being down around 50 or 60 up as high as 300 and that's again, that's biomass burning coming across the Andes and out into the, over Ecuador and into the tropical Pacific. On the DC-8 aircraft,
20:21
this represents a LIDAR measurements and LIDAR is simply a technique in which you shoot a beam of light down that is scattered by a particular molecule or material. The upper one would show particles, the bottom one shows ozone. When the light is scattered and comes back up,
20:41
all you have to do is divide by the velocity of light to find out at what altitude and so the airplane was flying along like this and down below it for that whole time, this shows half an hour but it was there the whole flight. There is a very intense plume and then later on the airplane flew through it and the plume was 130 parts per billion of ozone.
21:03
Well, this was about 500 miles north of Fiji at an altitude of five miles. The 130 parts per billion of ozone violates EPA standards in any US city but this was out over the tropical Pacific and the question was where did all that come from and one can trace it back by doing backward trajectories,
21:26
knowing what the wind directions have been for some time, you can trace it back and when these were traced back from Fiji, they came back across Australia and then clear over here into Africa in about 10 days and from the composition,
21:40
we believe that most of the ozone forming materials actually started in Africa and had still held together as a plume all the way over to Fiji. So, it says that pollution episodes at a long distance away from the start are becoming very common. Now, if I return to this slide that I started with,
22:03
I want to point out that in fact, we're looking at something which started out as being urban ozone, that is things formed in cities like Los Angeles but the general impression one gets is not that there are a lot of cities, that there's a city or two producing something here
22:22
but that the tropospheric ozone is present everywhere and that means we need to think about exactly what it is that was going on and this is now a summary then of what's been happening during the 20th century. The beginning of the 20th century,
22:42
these were the 13 largest cities in the world. It took one million people in order to be one of the 13 most populous cities in the world. Population of the world at that time was about 1.6 billion. Now, in 1995,
23:00
population of the world was about 5.8 or 9 billion, we expect it to be 6 billion, so an increase of a factor of four during this century and the 6 billion will be reached sometime next year and then you get places like Tokyo, Yokohama with almost 30 million people living in one metropolitan area. This is a major change
23:21
in the way that the world's population operates. There are far more people and more and more of them are living in cities. This map here shows 37 different cities that have populations now of two and a half million people or more and of course, all of the people living in all of these cities
23:42
want the same kind of lifestyle that those of us in this room want and there's no reason that they should, that we should have it and that they should not. So the question that we have is how do we accommodate this growth in cities, the growth in total population
24:01
and at the same time, take care of the environment? This is the expectation on the global population that we will be around eight and a half, around nine and a half or 10 billion people by the year 2050 and there's some error bar on that. There's not much error bar on the fact
24:21
that we'll be eight billion people by the year 2025 and so it's most of those two billion people that are added in there are going to live in cities. So the problems of the pollution of cities are going to be increasingly important but so far I've emphasized population
24:42
and that gives a misleading aspect because it's really population times affluence and affluence is probably more important than population and just to illustrate, I've shown here a map of the United States with the forested areas in the year 1620
25:04
when the Europeans had just begun to come over in any appreciable number and essentially the eastern half of the United States was virgin forest. By 1850, a lot of the eastern part of it had been broken up. The western part was still more or less the same
25:22
but now as you get into here, we see that virgin forest is essentially gone in the United States. So it isn't, when we look at all of the forest burning that's going on in the developing world now, what we're looking at is the same thing that was done in the United States
25:41
in the 18th and 19th centuries and what was done in Europe in centuries before that. So it's a process that has been part of mankind for a long time and now we've just found out that there are some severe penalties on a global basis from that. One of those penalties is the amount of carbon dioxide
26:01
in the atmosphere shown here in the measurements of Dave Keeling where you see the seasonal photosynthesis and decomposition but you're seeing it on this background of growing amounts of carbon dioxide in the atmosphere that the major contributory factor to that growing carbon dioxide is the burning of fossil fuels.
26:23
Here are the energy uses in the world in 1995. Traditional energy means fuel wood, charcoal, crop waste and so on. In these units, 1.8 terawatts. And then in the industrial energy,
26:40
what we see is that coal, gas and oil dominate. 85% of the industrial energy and 75% of the total energy is wrapped up in the fossil fuels. Nuclear and hydro play significant but not major roles and all of the others, wind power and solar photovoltaics and so on add up to less than 1% on this.
27:03
So at the present time and for the foreseeable future, the fossil fuels are going to be our main source of energy in the globe and they carry with it the penalty of carbon dioxide. If you put the carbon dioxide emissions in terms of the per capita use of energy,
27:21
then the United States is way out in front and what you see is that India, Nigeria, Indonesia, that there's very little emitted per person. So in the present circumstance, it isn't really the growing population, it's the growing population becoming more affluent and wealthier
27:40
and moving up the scale of production of energy and the use of that for their standard of living is as it's true in United States and Germany and so on. In other words, if we think about the pressures on the environment, it is partly population but it is very much more the fact that we have over a long period of time
28:02
been using energy in a way that assumes that there are no environmental problems associated with it. One thinks about the 19th century, at the beginning of the 19th century, the world was just starting to substitute steam power for animal and horsepower and then in the late part of the 19th century,
28:22
they discovered fossil fuels and in the first half of the 20th century, one found that the fossil fuels could give you enough energy to do many things you couldn't do before and thereby raise your standard of living and that has led to this existence of the developed countries as we know them
28:42
and in the second part of the 20th century, we found out there was a penalty that was associated with that and that penalty is the pressures that we placed on the environment and which we see with the tremendous amount of carbon dioxide that's going into the atmosphere, its accumulation in the atmosphere
29:01
and the problems that that will raise. Global temperature in the last century has gone up about seven tenths of a degree centigrade, a little over one degree Fahrenheit. The measurements for 1997 showed it as the warmest year ever and for 1998, the first five months,
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each month was the warmest month, the warmest January of all time was in January of 1998, the warmest February was in February of 1998 and so on and the Intergovernmental Panel on Climate Change said in 1995 that the balance of evidence
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suggests a discernible human influence on global climate. That is that the climate is changing and that we're partially, at least partially responsible for its changing. As we go into the new millennium, one of the major problems that we have in the world is how we take care of the burgeoning population,
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their legitimate desires for greater affluence without paying a tremendous environmental penalty and that means we're going to have to do an enormous amount of work on a variety of pollution problems, not only with the atmosphere but also with water and in general, just how we handle things
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when there isn't any place to throw things away. Thank you very much.