[00:00:29]
>> But. I know it's standing room only already so. Hello. Hello. We might as well get started all the seats are full and there's standing room only in case any of you are mistaken thinking that it's Steve Conan's brother who is a musician here today it's not so we thought maybe his rock star brother was attracting the crowd would everybody please silence their cell phones so we don't get into that I know some of you are still on your cell phones and we can.

[00:02:19]
Shut him off so we can avoid interruptions thank you I'm more and Weiner chair of the Woodruff school in mechanical engineering and it's a real pleasure to have you here today for the two thousand and seven Woodruff distinguished lecture. Who would have to sing or selectors were started in one thousand nine hundred and we've had a very distinguished group of speakers and you won't be disappointed today I'm sure.

[00:02:47]
The purpose of the lecture is to bring somebody to the Georgia Tech community who has had a technical education and background but has done things far beyond you expect most engineers or physical scientists to do and to talk to the Georgia Tech community about issues that are important to the community at large and that are related to technology.

[00:03:14]
The lecture is made possible by the generous generosity of George Woodruff who was a member of the class of one nine hundred seventeen I believe it was and the left us a significant endowment in the late one nine hundred eighty S. and at which time the school of mechanical engineering was named in his honor and we're fortunate begin today as we have ever since these lectures started to have a member of the family here with us George Woodruff granddaughter Missy Pierce is here with us today in the front row and continues to support.

[00:03:55]
Our speaker today is Dr Steve Coonan. Dr Cohen was born and raised in Brooklyn New York. Did his undergraduate work at Cal Tech in physics and his graduate work at MIT in Theoretical Physics in one nine hundred seventy five you joined the faculty at Cal Tech where he was until two thousand and four nearly thirty years for the last nine years he was there he was provost at Celtic.

[00:04:24]
His areas of interest are high energy physics and a variety of other physics related issues. He's a fellow of the American Physical Society the American Association for the Advancement of Science and a number of other organizations he's also been on and is on a number of high level advisory boards in the U.S. government including the National Science Foundation the Defense Department the Jasons group and the Defense Department in two thousand and four he joined British Petroleum as their chief scientist and his portfolio is to look beyond petroleum as he's discussed or has the title implies and into what are the energy issues for the.

[00:05:14]
Future and that's what is going to talk to us today we're very fortunate to have Dr Cohen join us today I give you Dr am. It is a great honor for me to be here and give this year's installment of the distinguished lectureship as a remark true award I think I knew about half of the previous one in the series about yours in the series and particularly happy to be joining that group I want to talk to you today about energy and particularly the technology aspects of energy this is a subject of that's of great importance for the future of society and yet one finds a tremendous amount of misinformation or if not ignorance and so what I would like to do is to take you through a discussion of energy technologies really from a physicist point of view given my own training I will try to be analytic quantitative and maybe most importantly I'm going to try to be factual and descriptive and not normative talking about the way the world really is as opposed to the way I think it should be which is a common confusion in discussions and of energy so when you start thinking about energy technology you realize it's not about the technologies alone but rather the technologies that we will develop and deploy depend of course upon the policies that are adopted by the government but also about the political economic social contexts in which those technologies are deployed because energy is ubiquitous it's not only about the technology itself but about other aspects of society we came to realizes as we were thinking about B.P.'s long term technology strategy that there are really four forces that will determine energy technologies in the future one is the strong growth in demand a second is the challenges associated with supplying energy to meet that demand a third is issues associated with security of supply and then a fourth all the environmental impacts associated with energy supply and use I want to take you briefly through each one of these four drivers hitting the highlights and then we'll turn to the technologies themselves and what conclusions one can draw from them so let's start in with demand and the headlines here are first of all strong growth in demand anticipated over the next thirty to fifty years associated largely with growing G.D.P. in the world but also with growing populations second is the issue of urbanization about half of the people in the world live in big cities right now that number will rise to seventy percent by two thousand and thirty and that determines the kind and quantity of energy that they will require And then of course a discussion of demand management and what can be done to at least slow the growth in demand.

[00:08:18]
This chart for me summarize the so much about the energy situation what its product is the tar memory energy per capita in good tools per year against the G.D.P. per capita in constant dollars and these are evolutionary tracks or over about twenty four. Years from one nine hundred eighty until essentially the present and when you look at this many things jump out at you first of all the U.S. is the high lawyer on the chart about twice that of other countries in the developed world but with a relatively constant energy use growing only very slowly.

[00:08:57]
The second is that other countries in the developing world are down here also growing relatively slowly smaller G.D.P. as per capita than the US as well. There are some fast movers on the chart with the way Australia takes off look at what happens to Ireland over here great growth accelerated growth in G.D.P. with not very much increased use in energy there are some countries that exhibit A non-monotonic growth if we go back up Russia for example given all the turmoil that happened in the one nine hundred ninety S.

[00:09:32]
you see Russia showing a non-monotonic variation. And then there is a broad swath of countries in the developing world that follow a more or less universal trajectory of increasing energy use as their G.D.P. goes and what sobering to realize is that there are about a billion people between the US the E.U. and Japan in the developed world there are roughly two and a half billion people in the rapidly developing economies of China and India and then there are another about two billion people in the world that aren't even on this chart that strong growth in G.D.P. is coupled with a strong growth in population the world's population a few years ago was six point three billion it will climb to nine billion by mid century with the trajectory shown there those two factors together give rise to an anticipated strong growth in energy in fact it will grow by about seventy percent to twenty thirty and double by mid century most of that increase will come from the developing countries shown here the energy uses both historically and projected in the O.E.C.D. countries shown in green the transition economies shown in yellow those are basically the former Soviet Union and then to the developing countries and you can see that that's where the energy growth will be.

[00:10:58]
This is illustrated even more dramatically by showing thirty years of absolute energy use now not per capita in various regions of the world on the extreme left you can see North America. Growing certainly but the really surprising feature of this chart is the very strong growth in Asia shown in the right hand set of data.

[00:11:24]
It's interesting also not to look only at the total quantity of energy required but how it is split among various uses most people when you say energy immediately think of automobiles and oil and in fact that is the most visible and personal use of energy in the developed world however transportation accounts for only about twenty five percent of the world's energy use.

[00:11:51]
Forty percent is consumed by the generation of electrical power and another forty percent is consumed in heating both in buildings and in industrial processes as the world develops transport and power will grow a bit disproportionately But by and large those fractions remain and as we think about the total energy picture it's useful to keep in mind that there are different kinds of energies and different energy use or say a word about energy efficiency and conservation first of all energy use depends more than upon G.D.P. There are multiple factors the economic mix that you have factories consume more energy than people sitting in offices the demographics younger people consume more energy than older people etc etc It's interesting to note that the US per capita energy and transport is more than three times that of Japan in part of course because the much larger size of the U.S. but also because of technology choices efficiency is a cost a wonderful thing and should be promoted and developed as much as one can but it's important to realize that it may not reduce demand either because it can be misused or because one is in a surprise limited situation for example if there is now not enough electricity in India to supply the at conditioning needs of people in India making air conditioners more efficient will certainly make it more Indians cooler but will not reduce the demand because it will simply be more Achan dition is used and so efficiency is important in the short to mid term in the developed world but will have not a great impact in the developing world efficiency can also be misused here is a chart summarizing what happens with the U.S. automobile fleet in one thousand nine hundred ninety S.

[00:13:44]
the net mpg of new cars sold in that decade went up by four point six percent However when you open it up a little bit what you realize is that the engine efficiency of new cars went up by an amazing twenty three percent in that decade wonderful engineering achievement but that efficiency was negated by increases in weight and improvements in performance by eighteen point four percent all right so you can make things more efficient but in the end it really is about conservation not efficiency.

[00:14:17]
OK let's turn to energy supply and here in the headlines off first of all there are significant energy resources the world is not going to run out of energy any time soon however we are going to see a growing fraction of non conventional energy sources in the mix as the decades evolve this is a wonderful chart on like very much it shows where the U.S. got its energy for the last two hundred fifty years.

[00:14:45]
And it shows at the time of the Civil War The US was getting most of its energy from wood and a little bit from coal as the nineteenth century evolved you can see that wood was displaced by coal was the industrial revolution gathered steam if you'll excuse the pun are and then is the transport all revolution took over in the early to mid twentieth century you see oil becoming a large fraction of the energy mix gas has recently supplanted oil and you can see the beginning of a nuclear wage in the one nine hundred eighty S.

[00:15:21]
or so more or less stagnating as we will discuss in a bit non hydro renewables of that little pink band up in the last two bars right now. What's interesting is that the total amount of energy in eight hundred fifty from wood is just about the same as the total amount of energy from wood today it's just a cost that society is energy needs have increased so dramatically over the last two hundred fifty years this is where the world got its energy over the last thirty five years you can see that oil is thirty six percent coal and natural gas are twenty five percent each roughly nuclear and hydro about six percent nuclear and hydro as you can see from the graph on the right are roughly constant over the last several decades at six percent gas has been growing or oil has been coming down and coal has been coming down but recently is experiencing a resurgence and we'll discuss the reasons for that in a moment.

[00:16:23]
It's interesting and important to break up the different fuels and how they're used differently all the world in recent years as used one hundred eighty six million barrels of oil equivalent per day never mind the units because they don't matter very much it's the relative magnitudes that matter power generation consumed roughly forty percent of that seventy six industry buildings and transport as shown there let's see how the different fuels have played into these different uses Oriel by far the largest fraction of it goes into transport smaller fraction scumming into generation in fact that's going down industry and some people still heat their buildings with oil.

[00:17:08]
Gas The second fossil fuel is mostly about heating twenty two of the thirty seven or thirty eight and then a growing fraction of power generation coal forty three is ascension all about electrical power very little uses apart from that biomass is mostly about buildings many people in the world still heat their buildings with biomass not only wood but dunk in the third world.

[00:17:39]
Renewables are essentially all about the electrical power generation and of course nuclear as well and so when you put it all together you get a picture that's pretty complicated but there are some lessons to take from this oil is mostly about transport and transports essentially only about oil.

[00:17:57]
Coal is essentially about power and gas is spread among them and the renewables are mostly about power and this is a business as usual projection of the primary energy sources over the next twenty five years and of course some history as well you can see that now and projections of new business as usual show that fossil fuels will provide the bulk of the world's energy eighty five percent of the world's energy in twenty thirty a significantly large fraction surprisingly large fraction is biomass and waste but again those are the traditional uses of biomass as shown on the right the growth rates of most energy sources are relatively modest except on the renewables which is solar wind and geothermal wave energy as well you can see even with the strong growth at six and a half percent by two thousand and thirty if the world doesn't do anything unexpected they will still be a very small fraction of the total.

[00:19:00]
So the question is if the world is powered now and in the foreseeable next decades by fossil fuels is there enough to meet that demand and the answer is yes if you look at all the world has in energy terms. About one and a half trillion barrels one one and a half trillion barrels of proven oil reserves in the ground or oil that we know is there and we can get out economically that corresponds to forty one years of use at the current rate the geologist believes that there is yet to find another equal amount to that and then there are all sorts of unconventional sources for oil toss and shale oil which we will discuss in a moment gas has sixty seven years at the present consumption rate a plausible amount yet to find and then enormous resources in gas hydrates if one could ever figure out how to tap into them.

[00:20:00]
This is on an energy for energy basis and so you can see that coal is the big gorilla here there are one hundred sixty four years of coal at the current consumption and constantly yet to find there are up to one thousand years of course no one has gone looking for coal yet in any serious way Oriel is of particular interest because if it's important for transportation and this is a curve from the International Energy Agency that shows how much oil is there at a given price.

[00:20:32]
In the last hundred fifty years the world has produced about a trillion barrels of oil shown by that first ball on the left at pretty low prices it's estimated that the OPEC countries in the Middle East have about another trillion barrels of oil also at very low cost all the conventional oil around the world in the non OPEC countries or outside of the Middle East about another trillion and then you can see a succession of other sources of oil deep water the Arctic.

[00:21:02]
Conversion of heavy oil shocks oil shales all providing another in total another four and a half trillion barrels of oil at costs that are less than today's sixty five or sixty dollars a barrel the world will need in the next twenty five years the amount of oil about a trillion barrels indicated by the with of that red bar today the world consumes about eighty five million barrels a day the with of that red bar corresponds to one hundred million barrels a day because that will be growth in the next twenty five years and so I look at this and conclude that the world is not likely to run out of oil anytime soon.

[00:21:44]
However there are issues associated with the fossil fuels and one of them is the dislocation of resources and the ensuing dependence upon imports by many of the consuming countries. This chart shows in energy terms the abundances of the resources in the three fossil fuels oil both conventional and unconventional gas and coal in various regions of the world shown on the same energy scale if you look first at the Middle East well of course everybody knows that's where the oil and gas are and sure enough those dollars are pretty big There is however no coal in the Middle East.

[00:22:25]
If you look at North America you can see that there's not much conventional on oil left but there is a lot of unconventional oil toss and shale oil a good bit of gas but an awful lot of coal if you look at Asia Pacific another demand Center China India.

[00:22:43]
Not much oil not much gas but a lot of coal. Interestingly if you look at the former Soviet Union they lucked out in the geo logical lottery and they got a lot of oil a lot of gas and an article. And so what you can conclude from looking at this.

[00:22:59]
Is that the oil is where the people aren't and the coal is where the people are and you can make that a little bit more quantitative by looking at the three largest energy markets North America Europe and Asia Pacific if you look at the two bars on the left for oil those three countries consume seventy eight percent of the daily production but have only ten percent of the reserves of oil gas is similarly mismatched the big countries to begin soon are sixty one percent and only fifteen percent of the reserves it's interesting that the gas reserves seventy percent of them all localized in four countries Russia Saudi Arabia Iran and Cutter have seventy percent of the world's gas reserves for coal the situation is much more equally matched the big consumers consume eighty eight percent of the production and sixty five percent of the reserves is what they have so it's natural to believe that our security of supply concerns become more important that the consuming countries will turn increasingly to coal and in fact that's certainly what we're seeing in China and to some extent in the U.S. that has other negative implications which will discuss in a moment.

[00:24:17]
OK environmental impacts and these common in two flavors are one of the local pollution concerns and it is really a remarkable achievement by the engineering folks and the fuel scientists that in the Western countries and increasingly stringent set of regulations has been met at reasonable cost by technology developments I live for Los Angeles I've lived in Los Angeles for thirty years and the air got palpably cleaner in the L.A. Basin even though the number of automobiles and the number of people increased dramatically.

[00:24:55]
That's not the case in China or India if you visited there recently but in fact it seems inconceivable that those societies will not address the local pollution question when it gets bad enough and they have the resources to do so and the technologies will be there in order to do that much more problematic in terms of environmental impacts is the issue of greenhouse gas emissions particularly C O two and their role in climate change and I want to spend a few minutes talking about that.

[00:25:25]
We know that C O two concentrations are rising and that is due to fossil fuel use this is the famous killing curve Osseo two concentrations started out at two hundred eighty ppm before the industrial revolution they are now at three hundred eighty four ppm I believe and going up at about two ppm a year we know that that is due to fossil fuel use from the isotopic ratios of the carbon we also know that the global temperature is increasing certainly has been increasing strongly in the last thirty years and in fact a shows a non-monotonic increase over the last hundred twenty years or so.

[00:26:05]
There are other indicators of climate change we see glaciers melting we see the ice packs diminishing in the Arctic not true in the Antarctic but in in the Arctic Yes the dire. Temperature difference between day and night is becoming compressed season seem to be advancing spring comes a little bit earlier in many parts of the world so it certainly looks like the climate is changing and there is a pause of all causal connection as was worked out by Arrhenius more than a century ago if the C O two goes up the temperature is going to go up eventually but one is looking now at a one percent effect in a very complex and noisy climate system the scientific case is further complicated by natural variability Why did the system vary as it did over the last several millennia where we know there have been substantial variations and frankly ill understood forcings particularly associated with manmade aerosols on the clouds that they produce.

[00:27:04]
The impacts of higher C O two are quite uncertain beyond simply saying that the temperature is very likely to go up Nevertheless many people have talked about five hundred and fifty ppm twice the pre-industrial value as a widely discussed stabilisation target above which it would be imprudent to let the concentration go.

[00:27:26]
That is reached under a straightforward extrapolation of the killing curve in about forty five years or fifty years on to business as usual scenarios so the world has about fifty years to deal with this problem actually shorter for reasons we'll discuss in a moment my own stance and that of B.P. is that precautionary action is well warranted even if the scientific case is not one hundred percent and we don't quite understand what the impacts will be the real questions are not to address all what could the world do and will the world do it and these are very complicated technical policy economic issues in order to do that there are two crucial facts about C O two science that you need to know in order to one think about what to do one is that the Earth can absorb the anthropogenic C O two only at a limited rates.

[00:28:17]
We are dumping C O two into the atmosphere faster than the system can absorb it and so it is accumulating in the atmosphere. What you need to understand is that emissions would have to drop to about half of their current value by the end of this century if we want to stabilize at five hundred fifty ppm and this has to happen in the face of a projected doubling of energy demand in the next fifty years so all energy production system if demand doesn't moderate has to get four times more called an efficient than it is right now emissions are growing at one and a half percent a year currently the other thing in this is the more extra ball part of the problem is that the C O two lives in the atmosphere for a very long time of order a thousand years which is much longer than any of the time scales that are of interest for human society what that means is that the atmosphere will accumulate emissions during this century it's not my political and pollution where if you stop polluting the distant pollution disappears after a week or so.

[00:29:24]
This stays in the atmosphere the upside of that is that it is only the integral of the emissions curve that really matters in raising the concentration and so near term growth can be offset by a sharper reductions long term but the downside is that because the emissions all growing exponentially the concentration is growing exponentially and so modest reduction in emissions only delay but do not prevent you from crossing the five hundred fifty ppm threshold a good rule of thumb is that if we can manage to reduce emissions by twenty percent that will only buy us fifteen years in seeing the concentration costs five fifty ppm Here are some quantitative courage.